The authors have no acknowledgment.

The patient provided written informed consent for the operation and use of medical data for scientific purposes. This research was performed in compliance with the Declarations of Helsinki and was approved by the local institution&#39;s human research ethics committee and institutional review board.
1. Operative setting and trocar placement
<ol>
	<li>After satisfactory anesthesia, place the patient in a supine, 30&#176; reverse Trendelenburg position and spread the legs apart. Perform the sterilized exposition and check the instrument availability.</li>
	<li>Ensure that the first surgeon stays in front of the robot console and the table-side surgeon stands between the patient&#39;s legs. Ensure the availability of the robotic system and robotic instruments (Table of Materials).</li>
	<li>Establish pneumoperitoneum through a 1 cm incision above the umbilicus using a Veress needle connected to the insufflator (set the pressure to 14 mmHg). Remove the Veress needle, transfer the insufflation tube to a 12 mm trocar, and then insert the trocar as a temporary camera port.</li>
	<li>Insert the robotic endoscope through the camera port and perform a diagnostic laparoscopy (the robotic endoscope is held by the assistant surgeon) to confirm adhesion status, exclude peritoneum metastasis, and evaluate operative feasibility. Subsequently, insert the remaining four trocars as follows, under the visual guidance of the endoscope.
	<ol>
		<li>Place 8 mm trocars in the right and left anterior axillary lines (AALs) under the costal margin, for the second (bipolar forceps) and third (Cadiere forceps) robotic arms, respectively.</li>
		<li>Place a 12 mm trocar 5 cm to the umbilicus in the right lateral position as the camera port.</li>
		<li>Place an 8 mm trocar 8 cm to the umbilicus at the superior left lateral position for the first (electrocoagulation hook) robotic arm.</li>
		<li>Place a 12 mm trocar right to the umbilicus in the right midclavicular line as the camera port. The assistant port is the original temporary camera port (step 1.3) (Figure 3). 
		NOTE: The location of the ports can be adjusted according to the lesion&#39;s location and the patient&#39;s body figure.</li>
	</ol>
	</li>
</ol>
2. Abdominal inspection and assessment of resectability
<ol>
	<li>Perform a full abdominal inspection using robotic endoscopy to observe the shape and size of the liver, gallbladder, and hepatoduodenal ligament, assessing for tumor resectability. Advance the endoscope into the abdominal cavity to rule out tumor metastasis.</li>
	<li>Dissect the lesser omentum from right to left with an electrocoagulation hook to descend the pylorus and duodenum. Create a Kocher&#39;s incision, about 5 cm, at the lateral side of the second part of the duodenum using an electrocoagulation hook to expose the retroduodenal portion of the common bile duct.</li>
	<li>Clip the distal and proximal stump of the common bile duct with an absorbable ligating clip.</li>
	<li>Transect the common bile duct in the superior edge of the pancreas using curved shears. Sample the tissue from the largest margin of the distal stump of the common bile duct and send it for frozen section pathological examination.</li>
	<li>Dissect the common bile duct and hepatic duct from caudal to cephalad direction, toward the cystic triangle. Confirm the presence of the cystic duct and artery. Dissect the cystic triangle using an electrocoagulation hook and determine the relationship between tumor and hepatic artery as well as portal vein. 
	NOTE: The cystic triangle is constituted by the common hepatic duct, cystic duct, and cystic artery.</li>
	<li>After ligation with an absorbable ligating clip, transect the cystic duct and artery using curved shears, and then remove them and the gallbladder from the gallbladder bed.</li>
	<li>Dissect the hepatic artery and portal vein using the intraglissonian approach8 with an electrocoagulation hook and bipolar forceps. Identify the position of the gastroduodenal artery, common hepatic artery, and portal vein, and fasten them with a rubber band. 
	&#8203;NOTE: The intraglissonian approach is used to dissociate the whole bundle of the left, middle, and right Glissonean pedicles beyond the hilar plate, and based on this, dissect the Glissonean pedicles, hepatic artery, and portal vein, respectively. Thereafter, a regular and precise hepatectomy is performed according to the ischemia line after selective hepatic flow occlusion.</li>
	<li>Skeletonize arteries and veins in the hilar region using an electrocoagulation hook and bipolar forceps.
	<ol>
		<li>Dissect the hepatoduodenal ligament and transect the common bile duct from bottom to top. Dissect the bile duct, proper hepatic artery, and portal vein completely with an electrocoagulation hook and bipolar forceps. Transect their branches with an ultrasonic scalpel to expose arteries and veins one by one.</li>
		<li>Resect the 8a, 8p, and 12 lymph nodes, peripheral nerve connective tissue, and hepatic portal plate with the electrocoagulation hook. Finally, remove fibrous connective tissue and lymph nodes along the duct.</li>
		<li>Mobilize the left and right portal veins and tie a rubber band around the left portal vein. Transect the branches of the portal vein from the right caudate lobe using an ultrasonic scalpel.</li>
	</ol>
	</li>
</ol>
3. Taj Mahal hepatectomy and regional lymphadenectomy
<ol>
	<li>Label the resection line of S4b, S5, and the caudate lobe on the liver&#39;s surface using an electrocoagulation hook. Transect the perihepatic ligaments and dissociate the bilateral halves of the liver with the electrocoagulation hook and bipolar forceps.</li>
	<li>Expand the Kocher&#39;s incision using an ultrasonic scalpel and an electrocoagulation hook. Resect lymph nodes 13a, 16a2, and part of the 7 and 9 groups using an ultrasonic scalpel and bipolar forceps. Remove these lymph nodes together with the previously dissected lymph nodes (8a, 8p, and 12) to achieve en bloc regional lymphadenectomy, which could also improve the exposure of the left caudate lobe.</li>
	<li>Transect the hepatic round ligament and its falciform ligaments using an electrocoagulation hook and bipolar forceps. Correct the resection line in order to expose intrahepatic bile ducts sufficiently, according to the actual situation during surgery.</li>
	<li>Occlude the left Glissonean pedicle with bulldog clamps and transect the left liver parenchyma (S4b) along the resection line with an ultrasonic scalpel. Similarly, occlude the right Glissonean pedicle and transect the right liver parenchyma (S5).</li>
	<li>Ligate the branches of the intrahepatic Glissonean system and hepatic veins using surgical clips and use an ultrasonic scalpel for parenchymal transection. Completely resect S4b and S5. 
	NOTE: To occlude the left and right Glissonean pedicles, use the intraglissonian approach before this process.</li>
	<li>Transect the liver parenchyma of the caudate lobe and the Spiegel lobe. Finally, transect the ventral caudal portion of S1.</li>
</ol>
4. Reconstruction of the intrahepatic bile ducts and bilateral hepaticojejunostomy
<ol>
	<li>Examine the cut surface of the liver and close the bile duct orifice of the caudate lobe with 4-0 sutures. Use a electrocoagulation hook (spray coagulation model, effect 3, 80 W) to stop small bleeds and bile leakage, while using a 4-0 suture to stop larger bleeds and bile leakage.</li>
	<li>Insert silicon stents into the branches of the left and right hepatic ducts to confirm the location of the ducts. Remove the stents and suture the adjacent walls of the right hepatic duct branches (B5d/7/8+6) and the left hepatic duct branches (B2-4) with 4-0 sutures. When the adjacent branches are sufficiently close, reconstruct the adjacent hepatic duct branches into an arch with a septum using a CV-4 suture (Figure 4A). Close the remaining small bile duct orifice with 4-0 sutures. Cover the cut surface of the liver with a hemostatic sponge.</li>
	<li>Open the gastrocolic ligament with an electrocoagulation hook and ultrasonic scalpel. Open the avascular area on the left of vessels of the middle colic artery to expose the jejunum. Retract the proximal jejunum through the transverse mesocolon.</li>
	<li>Perform retrocolic hepaticojejunostomy about 20 cm away from the ligament of Treitz for the left hepatic duct (B2-4) using a CV-4 suture in the hypotonic position of the jejunum. Using the same method, perform the hepaticojejunostomy for the right hepatic duct (b5d/7/8+6) and jejunum, and finish the bilateral hepaticojejunostomy (Figure 4). 
	NOTE: Before the hepaticojejunostomy, suitably mobilize the bile duct stumps for anastomosis. The 5-0 absorbable suture is preferred for hepaticojejunostomy, while the non-absorbable suture, such as the size CV-4 ePTFE monofilament suture is preferred for a wider anastomosis site.</li>
	<li>Transect the jejunum and jejunal mesentery using a cutting stapler away from the proximal stump of the biliary-enteric anastomosis. Perform a side-to-side jejuno-jejunostomy with the cutting stapler about 45 cm away from the distal stump of the biliary-enteric anastomosis. 
	&#8203;NOTE: To reduce the tension of hepaticojejunostomy, the key is the preparation of a tension-free jejunum loop. Transect 1-2 branches of jejunal artery, if necessary. Put two suspension sutures at both sides of the hepaticojejunostomy to further reduce the tension caused by gravity and intestinal motility.</li>
</ol>
5. Drain placement
<ol>
	<li>Examine the cut surface of the liver and anastomosis sites. Eliminate bleeding and bile leakage as described in step 4.1.</li>
	<li>Place two drainage tubes at the anterior and posterior areas of the biliary-enteric anastomosis, respectively.</li>
</ol>
6. Postoperative care
<ol>
	<li>Remove the nasogastric tube the day after the operation. Start an abrosia and expand to a normal diet in 3 days.</li>
	<li>Assess serum total bilirubin on postoperative day 1, day 3, day 7, and day 12. Perform a CT of the abdomen if total bilirubin on day four is elevated compared to day three.</li>
	<li>Assess drain bilirubin on postoperative day 1 to day 3. Remove the drain when drain bilirubin levels are less than three times the upper limit of normal serum amylase.</li>
	<li>Perform abdominal CT, blood routine examination, and blood biochemistry examination to assess postoperative recovery before discharge.</li>
</ol>

<ol>
	<li>H&#248;gdall, D., Lewinska, M., Andersen, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Desmoplastic+tumor+microenvironment+and+immunotherapy+in+cholangiocarcinoma.">Desmoplastic tumor microenvironment and immunotherapy in cholangiocarcinoma.</a> Trends in Cancer. 4 (3), 239-255 (2018).</li><li>Mansour, J. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hilar+cholangiocarcinoma:+expert+consensus+statement.">Hilar cholangiocarcinoma: expert consensus statement.</a> The Official Journal of the International Hepato Pancreato Biliary Association (Oxford). 17 (8), 691-699 (2015).</li><li>Li, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interventional+treatment+for+cholangiocarcinoma).">Interventional treatment for cholangiocarcinoma).</a> Frontiers in Oncology. 11, 671327 (2021).</li><li>Kawarada, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=S4a+++$5+with+caudate+lobe+(S+1)+resection+using+the+Taj+Mahal+liver+parenchymal+resection+for+carcinoma+of+the+biliary+tract.">S4a + $5 with caudate lobe (S 1) resection using the Taj Mahal liver parenchymal resection for carcinoma of the biliary tract.</a> Journal of Gastxointesdnal Surgery. 3 (4), 369-373 (1999).</li><li>Bismuth, H., Corlette, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrahepatic+cholangioenteric+anastomosis+in+carcinoma+of+the+hilus+of+the+liver.">Intrahepatic cholangioenteric anastomosis in carcinoma of the hilus of the liver.</a> Surgery Gynecology and Obstetrics. 140 (2), 170-178 (1975).</li><li>Amin, M. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> AJCC Cancer Staging Manual. 8th ed. , (2017).</li><li>Hirano, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+strategy+for+hilar+cholangiocarcinoma,+with+special+reference+to+the+limits+of+ductal+resection+in+right-sided+hepatectomies.">Treatment strategy for hilar cholangiocarcinoma, with special reference to the limits of ductal resection in right-sided hepatectomies.</a> Journal of Hepato-Biliary-Pancreatic Surgery. 14 (5), 429-433 (2007).</li><li>Machada, M. 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H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+the+management+of+cholangiocarcinomas.">Recent advances in the management of cholangiocarcinomas.</a> Seminars in Liver Disease. 14 (2), 109-114 (1994).</li><li>&#214;zg&#252;ner, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Camera-robot+calibration+for+the+da+Vinci+robotic+surgery+system.">Camera-robot calibration for the da Vinci robotic surgery system.</a> IEEE Transaction on Automation Science and Engineering. 17 (4), 2154-2161 (2020).</li><li>Araujo, R. L. C., Sanctis, M. A., Barroti, L. C., Coelho, T. R. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotic+approach+as+a+valid+strategy+to+improve+the+access+to+posterosuperior+hepatic+segments-Case+series+and+review+of+literature.">Robotic approach as a valid strategy to improve the access to posterosuperior hepatic segments-Case series and review of literature.</a> Journal of Surgical Oncology. 121 (5), 873-880 (2020).</li><li>Cillo, U., D'Amico, F. 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I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotic+approach+to+the+liver:+Open+surgery+in+a+closed+abdomen+or+laparoscopic+surgery+with+technical+constraints.">Robotic approach to the liver: Open surgery in a closed abdomen or laparoscopic surgery with technical constraints.</a> Surgical Oncology-Oxford. 33, 239-248 (2020).</li><li>Xu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotic+radical+resection+for+hilar+cholangiocarcinoma:+perioperative+and+long-term+outcomes+of+an+initial+series.">Robotic radical resection for hilar cholangiocarcinoma: perioperative and long-term outcomes of an initial series.</a> Surgical Endoscopy and Other Interventional Techniques. 30 (7), 3060-3070 (2016).</li><li>Chou, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotic+hilar+cholangiocarcinoma+radical+resection+compared+with+laparotomy+in+prognosis.">Robotic hilar cholangiocarcinoma radical resection compared with laparotomy in prognosis.</a> Zhonghua Wai Ke Za Zhi. 58 (3), 230-234 (2020).</li><li>Wang, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laparoscopic+surgery+and+robotic+surgery+for+hilar+cholangiocarcinoma:+an+updated+systematic+review.">Laparoscopic surgery and robotic surgery for hilar cholangiocarcinoma: an updated systematic review.</a> ANZ Journal of Surgery. 91 (1-2), 42-48 (2021).</li><li>Stremitzer, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prognosis+and+circumferential+margin+in+patients+with+resected+hilar+cholangiocarcinoma.">Prognosis and circumferential margin in patients with resected hilar cholangiocarcinoma.</a> Annals of Surgical Oncology. 28 (3), 1493-1498 (2021).</li><li>Gomez, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+specialized+multi-disciplinary+approach+and+an+integrated+pathway+on+outcomes+in+hilar+cholangiocarcinoma.">Impact of specialized multi-disciplinary approach and an integrated pathway on outcomes in hilar cholangiocarcinoma.</a> European Journal of Surgical Oncology. 40 (1), 77-84 (2014).</li><li>Nagino, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+surgical+treatment+for+perihilar+cholangiocarcinoma:+a+single-center+34-year+review+of+574+consecutive+resections.">Evolution of surgical treatment for perihilar cholangiocarcinoma: a single-center 34-year review of 574 consecutive resections.</a> Annals of Surgery. 258 (1), 129-140 (2013).</li><li>Matsuo, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Blumgart+preoperative+staging+system+for+hilar+cholangiocarcinoma:+analysis+of+resectability+and+outcomes+in+380+patients.">The Blumgart preoperative staging system for hilar cholangiocarcinoma: analysis of resectability and outcomes in 380 patients.</a> Journal of the American College of Surgeons. 215 (3), 343-355 (2012).</li><li>Jarnagin, W., Winston, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hilar+cholangiocarcinoma:+diagnosis+and+staging.">Hilar cholangiocarcinoma: diagnosis and staging.</a> The Official Journal of the International Hepato Pancreato Biliary Association (Oxford). 7 (4), 244-251 (2005).</li></ol>

The authors have no conflicts of interest.

Because the left hepatic duct is longer and less prone to anatomic variation than the right, the residual left hepatic duct after right hepatectomy has a decreased risk of a positive margin9. For hilar cholangiocarcinoma, a right hepatectomy is typically performed due to its anatomical advantages over a left hepatectomy However, increased complications and mortality rate of large-scale hepatectomy restrict the application of hemihepatectomy in hilar cholangiocarcinoma patients with poor liver function.
To preserve maximum liver parenchyma in patients with hilar cholangiocarcinoma, resection of the S4b, S5, and S1 (Taj Mahal hepatectomy) could be applied. Compared to the conventional operation, the Taj Mahal procedure significantly reduces the damage to normal liver tissue, preserves more normal liver tissue, and reduces the occurrence of serious postoperative complications, such as acute liver failure. More importantly, it follows the principle of radical tumor resection and can obtain a higher resection margin within P point or U point, thus ensuring the negative rate of longitudinal resection margin and transverse resection margin for hilar cholangiocarcinoma. Peripheral tissue of the bile duct can also completely be resected in Taj Mahal hepatectomy, which improves the negative rate of transverse incision margin as well. In the Taj Mahal hepatectomy, the liver must be transected along two planes to remove these liver segments, and four or more intrahepatic bile ducts will require anastomoses10. In the Taj Mahal hepatectomy, there are three technically difficult steps: the resection of the ventral part of the caudate lobule under non-hemihepatectomy,the safe dissection of vessels of the short hepatic veins and two or more hepaticojejunostomies. Because of the complex operative techniques, the Taj Mahal hepatectomy is seldom reported. The Taj Mahal procedure for the radical resection of hilar cholangiocarcinoma was first described in 19994. It was an open approach, and no serious perioperative complications were observed. Since then, few centers have reported the procedure due to its technical difficulty and a lack of surgical experience.
The robotic surgical system offers an optimal surgical view, which improves the exposure of the hilar structure and facilitates the skeletonization of the hilar duct with a thorough dissection of lymph nodes11. In addition, multiple hepaticojejunostomies are more precise and stable to perform. This parenchyma-preserving technique improves surgical tolerance and patient prognosis12. Several studies have reported the success of the radical robotic resection procedure in patients with hilar cholangiocarcinoma13,14,15. Xu et al16 reported 32 cases of robotic hemihepatectomy and caudate lobectomy in patients with hilar cholangiocarcinoma and proposed that the procedure only be conducted in strictly selected patients. A subsequent study further demonstrated acceptable long-term efficacy for robotic resection in patients with hilar cholangiocarcinoma17. These previous reports demonstrated an increasing trend for robotic radical resection in patients with hilar cholangiocarcinoma. A systematic review suggested that the feasibility and safety of radical surgery for hilar cholangiocarcinoma will be improved with technological innovations and the gradual accumulation of surgical experience, whether laparoscopic or robot-assisted systems18.
A margin-negative resection is a key factor affecting long-term survival in patients undergoing radical resection for hilar cholangiocarcinoma. The median survival (27-58 months) and 5-year survival (27%-47%) of patients with a negative margin are significantly longer compared to the median survival (12-21 months) and 5-year survival (0%-23%) of patients with a positive margin2,19,20,21,22,23. For hilar cholangiocarcinoma invading the bilateral 2nd-orderbile tract, a radical resection results in multiple stumps of the hepatic duct on the cutting surface. Performing hepatic duct reconstruction and hepaticojejunostomy safely and effectively is key to postoperative recovery and long-term outcomes. The authors&#39; experience indicated that a maximum of eight intrahepatic bile ducts could be formed into one orifice by hepatic ductoplasty.
According to a lateset systematic review, the average hospital stay for laparoscopic surgery and robotic surgery for hilar cholangiocarcinoma was 14 days18. However, the presented data showed that the level of total bilirubin returned to normal level on POD 12, which had already reached the standard of discharge. This patient was discharged on POD 17 because of some other complications.
This article shows that the robotic Taj Mahal hepatectomy is safe and feasible for minimally invasive, radical resection in patients with hilar cholangiocarcinoma. Robotic surgery seems to have advantages over laparoscopic and open approaches in the dissection and anastomosis of the hilar bile duct. As the radical resection of hilar cholangiocarcinoma varies based on the location and extent of the lesion, thorough preoperative medical imaging examination and multidisciplinary cooperation are essential.

Hilar cholangiocarcinoma is a type of malignant tumor that is typically resistant to radiotherapy and chemotherapy1. Most patients with hilar cholangiocarcinoma can only survive 1 year after the diagnosis. Surgical resection is the only effective treatment for hilar cholangiocarcinoma2. Recently, several approaches have been proposed for the treatment of hilar cholangiocarcinoma3.
The Taj Mahal procedure comprises complete resection of S4b, S5, and S1 combined with regional lymphadenectomy, extrahepatic bile duct resection, hilar bile duct reconstruction, and hepaticojejunostomy4. Different from conventional hilar cholangiocarcinoma radical resection, the Taj Mahal procedure does not require a large-scale liver resection such as hemihepatectomy, thus preserving the maximum residual liver volume for patients, which greatly improves patient&#39;s tolerance to the surgery and may reduce the incidence of postoperative complications. However, the Taj Mahal procedure is technically demanding and has not been widely applied. The robotic surgical system provides multiple instruments and has many advantages over laparoscopic surgery, which could make the dissection and suturing more precise. The protocol herein presents a robotic hepatic S4b, S5, and S1 resection using the Taj Mahal procedure for Bismuth type IVa hilar cholangiocarcinoma5.
Indications 
Patients with Bismuth type II, III, and selected type IV hilar cholangiocarcinoma wherein the bilateral hepatic artery and portal vein are not widely invaded, especially those with liver function impairment require treatment via hemihepatectomy2,3,4,6.
Contraindication 
Tumor massively invades the hepatic artery or portal vein and needs resection and reconstruction of vessels by preoperative imaging and intraoperativeassessment. The upper extent of the tumor far exceeds the U Point defined as the bend between the transverse portion and the umbilical portion of the left portal vein or P point defined as the bifurcation of the anterior branch and the posterior branch of the right portal vein7.
Case presentation 
A 32-year-old Chinese man presented with jaundice and tea-colored urine. The patient had a 10-year history of heavy drinking and smoking. Laboratory examinations revealed elevated CA19-9 (31.48 U/mL) and total bilirubin (145.7 &#956;mol/L). Severe obstruction with partial thickening of the hilar bile duct wall was observed in Magnetic Resonance Cholangiopancreatography (MRCP) (Figure 1) and 3D reconstruction of MRI (Figure 2). The patient was diagnosed with Bismuth IV4a hilar cholangiocarcinoma. Vascular invasion in the porta hepatis was not seen in the preoperative evaluation and intraoperative observation. A multidisciplinary team decided to perform radical resection using a robotic Taj Mahal procedure.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>4-0 Non-Absorbable Suture</td>
			<td>Ethicon, USA</td>
			<td>W8761</td>
			<td>Synthetic non-absorbable Suture</td>
		</tr>
		<tr>
			<td>5-0 Non-Absorbable Suture</td>
			<td>Ethicon, USA</td>
			<td>W8556</td>
			<td>Synthetic non-absorbable Suture</td>
		</tr>
		<tr>
			<td>Collagen Sponge</td>
			<td>Beidi, CHINA</td>
			<td>20143642302</td>
			<td>Used for hemostasis</td>
		</tr>
		<tr>
			<td>Da Vinci Robotic Surgical System</td>
			<td>Intuitive&#160;Surgical, USA</td>
			<td>Si</td>
			<td>Surgical Robot Instrument</td>
		</tr>
		<tr>
			<td>Disposable Ligation Clip(Medium)</td>
			<td>KANG JI ,CHINA</td>
			<td>KJ-JZJ06ML</td>
			<td>Used for ligature</td>
		</tr>
		<tr>
			<td>Endo GIA 60 mm Articulating Stapler with Tri-Stapler Technology</td>
			<td>Covidien (Dublin, Ireland)</td>
			<td>EGIA60AMT</td>
			<td>Laparoscopic Surgical Stapler</td>
		</tr>
		<tr>
			<td>EndoWrist Cadiere Forceps</td>
			<td>Intuitive&#160;Surgical, USA</td>
			<td>420049</td>
			<td>Surgical Robot Instrument</td>
		</tr>
		<tr>
			<td>ENDOWRIST Fenestrated Bipolar Forceps</td>
			<td>Intuitive&#160;Surgical, USA</td>
			<td>470205</td>
			<td>Surgical Robot Instrument</td>
		</tr>
		<tr>
			<td>EndoWrist Large Needle Driver</td>
			<td>Intuitive&#160;Surgical, USA</td>
			<td>420006</td>
			<td>Surgical Robot Instrument</td>
		</tr>
		<tr>
			<td>EndoWrist Permanent Cautery Hook</td>
			<td>Intuitive&#160;Surgical, USA</td>
			<td>420183</td>
			<td>Surgical Robot Instrument</td>
		</tr>
		<tr>
			<td>Gore-Tex Suture</td>
			<td>Gore, USA</td>
			<td>4N04</td>
			<td>Synthetic non-absorbable Suture</td>
		</tr>
		<tr>
			<td>Harmonic Ace Curved Shears</td>
			<td>Ethicon, USA</td>
			<td>420275</td>
			<td>Used for cutting and coagulation</td>
		</tr>
		<tr>
			<td>High Frequency Electrotome</td>
			<td>COVIDIEN, USA</td>
			<td>FORCE FX-8C</td>
			<td>Used for electrocoagulation hemostasis</td>
		</tr>
		<tr>
			<td>Silicone Catheter</td>
			<td>Kang Wei, CHINA</td>
			<td>Fr8</td>
			<td>Used for define the bile duct</td>
		</tr>
		<tr>
			<td>Specimen Fetch Bag</td>
			<td>GZTK, CHINA</td>
			<td>HSD-130</td>
			<td>Used for removeing the specimen</td>
		</tr>
	</tbody>
</table>

robotic taj mahal hepatectomy for hilar cholangiocarcinoma

Hilar cholangiocarcinoma is the most common malignant tumor of the biliary tract. Radical surgical resection is the only effective treatment option. In this study, a 32-year-old male patient with Bismuth Type IVa hilar cholangiocarcinoma underwent radical robotic resection of hepatic S4b, S5, and S1 (Taj Mahal hepatectomy) combined with regional lymphadenectomy, hilar bile duct reconstruction, and hepaticojejunostomy by the robotic surgical system. Postoperative pathological examination showed moderately-differentiated adenocarcinoma of the hilar bile duct. The surgical margins of the liver and bile ducts were negative. Recovery was smooth and the patient was discharged on the 17th postoperative day. The robotic surgical system and associated multiple instruments along with flexible and precise movements is suitable for the local hepatectomy around the porta hepatis, and delicate reconstruction of the hilar bile duct with a smaller diameter. This first clinical application study found that robotic Taj Mahal hepatectomy for hilar cholangiocarcinoma is safe and feasible and needs more experience for the evaluation of its long-term outcomes.

The operation was eventually completed with trimming of the hepatic ducts (Figure 4A) and the anastomosis of the bilateral hepaticojejunostomy (Figure 4B). The total operative time was 340 min with an estimated blood loss of 100 mL (Table 1). The enhanced recovery after surgery (ERAS) pathway of the People&#39;s Liberation Army (PLA) General Hospital was used during the postoperative recovery period in the surgical ward. Total bilirubin was measured on postoperative days (PODs) 1 (157.5 &#956;mol/L), 3 (162.3 &#956;mol/L), 7 (127.6 &#956;mol/L), and 12 (45.9 &#956;mol/L) to assess recovery. The drain was removed, and the patient was discharged on POD 17.
A pathological analysis of the specimen revealed a moderately-differentiated cholangiocarcinoma (IVa, T3N2M0, AJCC 8th edition)5. The surgical margins of the liver and bile ducts were negative. Immunohistochemical staining was positive for CA19-9, CD10, CDX-2, CEA, CK19, CK7, E-cadherin, EMA, muc-1, MUC-5AC, P53, MLH1, MSH2, MSH6, PMS2, and HER-2, and was negative for CD34, CK20, Syn, muc-2, and muc-5AC. The patient had no laboratory and radiological evidence of recurrence or metastasis 3 months postoperatively (Figure 5).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63648/63648fig01.jpg" /> 
Figure 1: MRCP scan showing the obstruction in the hilar bile duct. The yellow circle indicates the site of cholangiocarcinoma. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63648/63648fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/63648/63648fig02.jpg" /> 
Figure 2: 3D reconstruction of MRI. (A) 3D reconstruction model of the lesion, hilar bile duct, and vessels.Red tubes are arteries, blue tubes are portal veins, green tubes are bile ducts, yellow regions are hilar cholangiocarcinoma, and orange regions are swollen lymph nodes. (B) 3D reconstruction model of the hilar bile duct. B2-B8: Each branch of the intrahepatic bile duct. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63648/63648fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/63648/63648fig03.jpg" /> 
Figure 3: Trocar placement. Five trocars were used. 1: port for the first robotic arm; 2: port for the second robotic arm; 3: port for the third robotic arm; C: camera port; A: assistant port; red circle: 8 mm trocar; blue circle: 12 mm trocar; RAAL: right middle axillary line; LAAL: left anterior axillary line. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63648/63648fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/63648/63648fig04.jpg" /> 
Figure 4: Taj Mahal hepatectomy and bilateral hepaticojejunostomy. (A) Identification of the stumps of the intrahepatic bile duct. B: bile, RHA: right hepatic artery, LHA: left hepatic artery, HA: hepatic artery IVC: inferior vena cava (B) The red circles indicate the sites of the hepaticojejunostomy of the right and left intrahepatic bile ducts. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63648/63648fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/63648/63648fig05.jpg" /> 
Figure 5: MRI of the patient obtained 3 months postoperatively. The red circle indicates the area of the operative region; changes after Taj Mahal hepatectomy for hilar cholangiocarcinoma; mild dilatation of intrahepatic bile duct; liver regeneration without tumor recurrence. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63648/63648fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Variable</td>
			<td>Outcome</td>
		</tr>
		<tr>
			<td>Intraoperative</td>
			<td></td>
		</tr>
		<tr>
			<td>Operative time, minutes</td>
			<td>340</td>
		</tr>
		<tr>
			<td>Intraoperative blood loss, mL</td>
			<td>100</td>
		</tr>
		<tr>
			<td>Postoperative</td>
			<td></td>
		</tr>
		<tr>
			<td>Drain removal, days</td>
			<td>17</td>
		</tr>
		<tr>
			<td>Postoperative hospital stay, days</td>
			<td>17</td>
		</tr>
		<tr>
			<td>Pathological diagnosis</td>
			<td>moderately-differentiated cholangiocarcinoma, 2.0cm</td>
		</tr>
		<tr>
			<td>Positive markers</td>
			<td>CA19-9, CD10, CDX-2, CEA, CK19, CK7, E-cadherin, EMA, muc-1, MUC-5AC, P53, MLH1, MSH2, MSH6, PMS2, HER-2</td>
		</tr>
		<tr>
			<td>Negative markers</td>
			<td>CD34, CK20, Syn, muc-2, muc-5AC</td>
		</tr>
	</tbody>
</table>
Table 1: Representative results of surgery.

Watch this Scientific Journal Video about Robotic Taj Mahal Hepatectomy for Hilar Cholangiocarcinoma at JoVE.com

Robotic Taj Mahal Hepatectomy for Hilar Cholangiocarcinoma

Robotic resection of hepatic S4b, S5, and S1 using the Taj Mahal procedure is feasible and safe for selected patients with hilar cholangiocarcinoma. The step-by-step details for this surgery are presented here.

Hilar cholangiocarcinoma is the most common malignant tumor of the biliary tract. Radical surgical resection is the only effective treatment option. In ...

robotic-taj-mahal-hepatectomy-for-hilar-cholangiocarcinoma

Nanyang Technological University

Research

JoVE Journal

Medicine

3.1K Views.  Medicine school of Chinese PLA. Robotic resection of hepatic S4b, S5, and S1 using the Taj Mahal procedure is feasible and safe for selected patients with hilar cholangiocarcinoma. The step-by-step details for this surgery are presented here.

Video: Robotic Taj Mahal Hepatectomy for Hilar Cholangiocarcinoma

Remote Magnetic Navigation for Accurate, Real-time Catheter Positioning and Ablation in Cardiac Electrophysiology Procedures

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac substrates such as left atrial flutter. This protocol describes all the clinical and invasive interventional steps performed during a human electrophysiological study and ablation to assess the accuracy, safety and real-time navigation of the Catheter Guidance, Control and Imaging (CGCI) system. Patients who underwent ablation of a right or left atrium flutter substrate were included. Specifically, data from three left atrial flutter and two counterclockwise right atrial flutter procedures are shown in this report. One representative left atrial flutter procedure is shown in the movie. This system is based on eight coil-core electromagnets, which generate a dynamic magnetic field focused on the heart. Remote navigation by rapid changes (msec) in the magnetic field magnitude and a very flexible magnetized catheter allow real-time closed-loop integration and accurate, stable positioning and ablation of the arrhythmogenic substrate.

This report provides a detailed description of a new remote navigation system based on magnetic driven forces, which has been recently introduced as a new robotic tool for human cardiac electrophysiology procedures.

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac ...

Robotic Ablation of Atrial Fibrillation

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between pulmonary vein (PV) and left atrium (LA) is created. This conduction block prevents AF, which is triggered by irregular electric activity originating from the PV. However, transmural atrial lesions are required which can be challenging. Re-conduction and AF recurrence occur in 20 - 40% of the cases. Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new remote catheter system (RCS), is presented. Objective of this article is to show feasibility of robotic AF ablation with a novel system. Materials and Methods: After interatrial trans-septal puncture is performed using a long sheath and needle under fluoroscopic guidance. The needle is removed and a guide wire is placed in the left superior PV. Then an ablation catheter is positioned in the LA, using the sheath and wire as guide to the LA. LA angiography is performed over the sheath. A circular mapping catheter is positioned via the long sheath into the LA and a three-dimensional (3-D) anatomical reconstruction of the LA is performed. The handle of the ablation catheter is positioned in the robotic arm of the Amigo system and the ablation procedure begins. During the ablation procedure, the operator manipulates the ablation catheter via the robotic arm with the use of a remote control. The ablation is performed by creating point-by-point lesions around the left and right PV ostia. Contact force is measured at the catheter tip to provide feedback of catheter-tissue contact. Conduction block is confirmed by recording the PV potentials on the circular mapping catheter and by pacing maneuvers. The operator stays out of the radiationfield during ablation. Conclusion: The novel catheter system allows ablation with high stability on low operator fluoroscopy exposure.

Pulmonary vein isolation (PVI) with an ablation catheter is a curative treatment for atrial fibrillation (AF). Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new robotic catheter system is presented. The goal of the procedure is electrical block between pulmonary vein and left atrium.

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between ...

Visualization of Vascular and Parenchymal Regeneration after 70% Partial Hepatectomy in Normal Mice

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the silicone compound, via a 26 G catheter, into the portal or hepatic vein. After silicone injection, organs were explanted and prepared for ex-vivo micro-CT (&#181;CT) scanning. The silicone injection procedure is technically challenging. Achieving a successful outcome requires extensive microsurgical experience from the surgeon. One of the challenges of this procedure involves determining the adequate perfusion rate for the silicone compound. The perfusion rate for the silicone compound needs to be defined based on the hemodynamic of the vascular system of interest. Inappropriate perfusion rate can lead to an incomplete perfusion, artificial dilation and rupturing of vascular trees.
The 3D reconstruction of the vascular system was based on CT scans and was achieved using preclinical software such as HepaVision. The quality of the reconstructed vascular tree was directly related to the quality of silicone perfusion. Subsequently computed vascular parameters indicative of vascular growth, such as total vascular volume, were calculated based on the vascular reconstructions. Contrasting the vascular tree with silicone allowed for subsequent histological work-up of the specimen after &#181;CT scanning. The specimen can be subjected to serial sectioning, histological analysis and whole slide scanning, and thereafter to 3D reconstruction of the vascular trees based on histological images. This is the prerequisite for the detection of molecular events and their distribution with respect to the vascular tree. This modified silicone injection procedure can also be used to visualize and reconstruct the vascular systems of other organs. This technique has the potential to be extensively applied to studies concerning vascular anatomy and growth in various animal and disease models.

Tools used for visualizing vascular regeneration require methods for contrasting the vascular trees. This film demonstrated a delicate injection technique used to achieve optimal contrasting of the vascular trees and illustrate the potential benefits resulting from a detailed analysis of the resulting specimen using &#181;CT and histological serial sections.

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the ...

Method of Direct Segmental Intra-hepatic Delivery Using a Rat Liver Hilar Clamp Model

Major hepatic surgery with inflow occlusion, and liver transplantation, necessitate a period of warm ischemia, and a period of reperfusion leading to ischemia/reperfusion (I/R) injury with myriad negative consequences. Potential I/R injury in marginal organs destined for liver transplantation contributes to the current donor shortage secondary to a decreased organ utilization rate. A significant need exists to explore hepatic I/R injury in order to mediate its impact on graft function in transplantation. Rat liver hilar clamp models are used to investigate the impact of different molecules on hepatic I/R injury. Depending on the model, these molecules have been delivered using inhalation, epidural infusion, intraperitoneal injection, intravenous administration or injection into the peripheral superior mesenteric vein. A rat liver hilar clamp model has been developed for use in studying the impact of pharmacologic molecules in ameliorating I/R injury. The described model for rat liver hilar clamp includes direct cannulation of the portal supply to the ischemic hepatic segment via a side branch of the portal vein, allowing for direct segmental hepatic delivery. Our approach is to induce ischemia in the left lateral and median lobes for 60 min, during which time the substance under study is infused. In this case, pegylated-superoxide dismutase (PEG-SOD), a free radical scavenger, is infused directly into the ischemic segment. This series of experiments demonstrates that infusion of PEG-SOD is protective against hepatic I/R injury. Advantages of this approach include direct injection of the molecule into the ischemic segment with consequent decrease in volume of distribution and reduction in systemic side effects.

A unique rat liver hilar clamp model was developed for studying the impact of pharmacologic molecules in ameliorating ischemia-reperfusion injury. This model includes direct cannulation of the portal supply to the ischemic liver segment via a branch of the portal vein, allowing for direct hepatic delivery.

Major hepatic surgery with inflow occlusion, and liver transplantation, necessitate a period of warm ischemia, and a period of reperfusion leading to ...

Robotic Lateral Pancreaticojejunostomy for Chronic Pancreatitis

Lateral pancreaticojejunostomy (LPJ) has shown good postoperative outcomes in patients with painful, morphine dependent, chronic pancreatitis (CP). The recent rise of robotic and laparoscopic pancreatic surgery has found benefits such as reduced time to functional recovery. Few studies have reported on the feasibility, technique and outcome of robotic LPJ, especially including transection of the gastroduodenal artery. The present study describes the main steps for robotic LPJ in a patient with painful chronic pancreatitis with a dilated main pancreatic duct. The patient underwent robotic LPJ. The LPJ anastomosis is performed using a running suture technique in a longitudinal side-to-side manner. Routinely, the gastroduodenal artery is transected to drain the entire length of the main pancreatic duct. The patient is in French position; 7 trocars are placed (4 robotic, 2 laparoscopic assistants, 1 liver-retractor). After docking of the robot system, the omental bursa is opened, and the right gastroepiploic artery and vein are ligated at their base at the lower border of the pancreas. Intraoperative ultrasonography is performed in order to determine trajectory of the dilated main pancreatic duct which is opened for its entire length after the gastroduodenal artery has been suture ligated both cranially and caudally from the main pancreatic duct. A Roux limb is created, and a latero-lateral PJ is fashioned using several 3-0 barbed sutures. A stapled jejuno-jejunostomy is created at sufficient distance from the pancreatic anastomosis, aided by a 50 cm suture. The described technique for robotic LPJ is a complex but feasible operation for patients with treatment refractory CP and a dilated main pancreatic duct. Due to its complexity, implementation in high volume centers with extensive experience with CP surgery may improve outcomes.

Robotic lateral pancreaticojejunostomy (RLPJ) may be used in patients with painful, morphine dependent, chronic pancreatitis and a dilated main pancreatic duct. We describe a standardized and reproducible technique for RLPJ, which includes transection of the gastroduodenal artery.

Lateral pancreaticojejunostomy (LPJ) has shown good postoperative outcomes in patients with painful, morphine dependent, chronic pancreatitis (CP). The ...

Use of 3D Robotic Ultrasound for In Vivo Analysis of Mouse Kidneys

Common modalities for in vivo imaging of rodents include positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US). Each method has limitations and advantages, including availability, ease of use, cost, size, and the use of ionizing radiation or magnetic fields. This protocol describes the use of 3D robotic US for in vivo imaging of rodent kidneys and heart, subsequent data analysis, and possible research applications. Practical applications of robotic US are the quantification of total kidney volume (TKV), as well as the measurement of cysts, tumors, and vasculature. Although the resolution is not as high as other modalities, robotic US allows for more practical high throughput data collection. Furthermore, using US M-mode imaging, cardiac function may be quantified. Since the kidneys receive 20%-25% of the cardiac output, assessing cardiac function is critical to the understanding of kidney physiology and pathophysiology.

Use of 3D Robotic Ultrasound for In Vivo Analysis of Mouse Kidneys

This protocol demonstrates robotic ultrasound (US) as a practical, cost-effective, and quick alternative to traditional non-invasive image modalities.

Common modalities for in vivo imaging of rodents include positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), ...

Robotic Left Hepatectomy using Indocyanine Green Fluorescence Imaging for an Intrahepatic Complex Biliary Cyst

Biliary cysts (BC) are rare congenital dilatations of intra- and extrahepatic parts of the biliary tract and bear a significant risk of carcinogenesis. Surgery is the cornerstone treatment for patients with BC. While total BC excision and Roux-Y hepaticojejunostomy is the treatment method of the choice in patients with extrahepatic BC (i.e., Todani I-IV), patients with intrahepatic BC (i.e., Todani V) benefit the most from a surgical liver resection. In recent years, minimally invasive liver surgery (MILS) including robotic MILS has gained more acceptance as a feasible, safe, and effective procedure for the treatment of both benign and malignant indications. Robotic major MILS is still considered technically demanding and a detailed description of the technical approach during robotic major MILS has only been limitedly discussed in the literature. The current article describes the main steps for a robotic left hepatectomy in a patient with a large BC Todani Type V. The patient is in French position with 5 trocars placed (4 robotic, 1 laparoscopic assistant). After mobilizing the left hemiliver, the left and right hepatic artery are dissected carefully followed by a cholecystectomy. Intraoperative ultrasound is performed to confirm localization and margins of the BC. The Left hepatic artery and left portal vein are isolated, clipped, and divided. Indocyanine green (ICG) fluorescence imaging is used regularly during the entire procedure to visualize and confirm biliary tract anatomy and the BC. Parenchymal transection is performed with robotic cautery hook for the superficial part and robotic cautery spatula, bipolar cautery, and vessel sealer for the deeper parenchyma. The postoperative course was uncomplicated. A robotic left hepatectomy is technically demanding, yet a feasible and safe procedure. ICG-fluorescence imaging aids in delineating the BC and bile duct anatomy. Further, comparative studies are needed to confirm clinical benefits of robotic MILS for benign and malignant indications.

Robotic liver surgery has gained more acceptance as a feasible, safe, and effective procedure for the treatment of both benign and malignant indications. However, robotic left hepatectomy is still technically demanding. We describe our surgical technique of a robotic left hepatectomy using indocyanine green fluorescence imaging for a large biliary cyst.

Biliary cysts (BC) are rare congenital dilatations of intra- and extrahepatic parts of the biliary tract and bear a significant risk of carcinogenesis. ...

Robotic Cochlear Implantation for Direct Cochlear Access

Robot-assisted systems offer great potential for gentler and more precise cochlear implantation. In this article, we provide a comprehensive overview of the clinical workflow for robotic cochlear implantation using a robotic system specifically developed for a minimally invasive, direct cochlear access. The clinical workflow involves experts from various disciplines and requires training to ensure a smooth and safe procedure. The protocol briefly summarizes the history of robotic cochlear implantation. The clinical sequence is explained in detail, beginning with the assessment of patient eligibility and covering surgical preparation, preoperative planning with the special planning software, drilling of the middle ear access, intraoperative imaging to confirm the trajectory, milling of the inner ear access, insertion of the electrode array, and implant management. The steps that require special attention are discussed. As an example, the postoperative outcome of robotic cochlear implantation in a patient with advanced otosclerosis is presented. Finally, the procedure is discussed in the context of the authors' experience.

Robotic cochlear implantation is a procedure for minimally invasive inner ear access. Compared to conventional surgery, robotic cochlear implantation involves additional steps that need to be carried out in the operating room. In this article we give a description of the procedure and highlight the important aspects of robotic cochlear implantation.

Robot-assisted systems offer great potential for gentler and more precise cochlear implantation. In this article, we provide a comprehensive overview of ...

Isolation of Regenerating Hepatocytes after Partial Hepatectomy in Mice

Partial hepatectomy has been widely used to investigate liver regeneration in mice, but the isolation of high yields of viable hepatocytes for downstream single-cell applications is challenging. A marked accumulation of lipids within regenerating hepatocytes is observed during the first 2 days of normal liver regeneration in mice. This so-called transient regeneration-associated steatosis (TRAS) is temporary but partially overlaps the major proliferative phase. Density-gradient purification is the backbone of most existing protocols for the isolation of primary hepatocytes. As gradient purification relies on the density and size of cells, it separates non-steatotic from steatotic hepatocyte populations. Therefore, fatty hepatocytes often are lost, yielding non-representative hepatocyte fractions. 
The presented protocol describes an easy and reliable method for the in vivo isolation of regenerating hepatocytes regardless of their lipid content. Hepatocytes from male C57BL/6 mice are isolated 24-48 h after hepatectomy by a classic two-step collagenase perfusion approach. A standard peristaltic pump drives the warmed solutions via the catheterized inferior vena cava into the remnant, using a retrograde perfusion technique with outflow through the portal vein. Hepatocytes are dissociated by collagenase for their release from the Glisson's capsule. After washing and careful centrifugation, the hepatocytes can be used for any downstream analyses. In conclusion, this paper describes a straightforward and reproducible technique for the isolation of a representative population of regenerating hepatocytes after partial hepatectomy in mice. The method may also aid the study of fatty liver disease.

Lipid-laden hepatocytes are inherent to liver regeneration but are usually lost upon density-gradient centrifugation. Here, we present an optimized cell isolation protocol that retains steatotic hepatocytes, yielding representative populations of regenerating hepatocytes after partial hepatectomy in mice.

Partial hepatectomy has been widely used to investigate liver regeneration in mice, but the isolation of high yields of viable hepatocytes for downstream ...

Fluorescent Laparoscopic Central Hepatectomy for Liver Cancer Using Indocyanine Green Negative Staining

Laparoscopic hepatectomy is an important treatment method for liver cancer. In the past, the resection boundary was usually determined by intraoperative ultrasound, important vascular structures, and surgeon experience. With the development of anatomical hepatectomy, visual surgery technology has gradually been applied to this type of surgery, particularly indocyanine green (ICG)-guided anatomical hepatectomy. As ICG can be specifically ingested by hepatocytes and used for fluorescence tracing, negative staining techniques have been applied according to different tumor positions. Under ICG fluorescent guidance, the surface boundary and deep resection plane can be more accurately displayed during liver resection. Thus, the tumor-bearing liver segment can be anatomically removed, which helps to avoid damage to important vessels and reduce ischemia or congestion of the remaining liver tissue. Finally, the incidence of postoperative biliary fistula and liver dysfunction is reduced; therefore, a better prognosis is obtained after the resection of liver cancer. Centrally located liver cancer is usually defined as a tumor located at segments 4, 5, or 8 that requires resection of the middle section of the liver. These are among the most difficult hepatectomies to perform because of the large surgical wounds and multiple vessel transections. Based on the specific tumor location, we formulated the required resection ranges by designing personalized fluorescent staining strategies. By completing anatomical resection based on the portal territory, this work aims to achieve the best therapeutic effect.

The present protocol describes fluorescent negative staining in laparoscopic central hepatectomy. This technique can make hepatectomy more accurate and precise.

Laparoscopic hepatectomy is an important treatment method for liver cancer. In the past, the resection boundary was usually determined by intraoperative ...