https://orcid.org/0000-0002-6808-9801
Abstract
With the spread of minimally invasive surgery (MIS), various MIS-specific iatrogenic complications have been reported; however, subserosal bile infiltration of the gallbladder has not been documented. We report a case of subserosal bile infiltration occurring during robot-assisted radical right nephrectomy for clear cell renal carcinoma after robot-assisted partial nephrectomy. Following right kidney resection, dark green discoloration of the gallbladder was observed. Reviewing the operative video revealed that the color change developed during retraction with a snake retractor. Although no bile spillage was observed, laparoscopic cholecystectomy was performed because gallbladder injury was suspected. During dissection from the gallbladder bed, bile was observed within the subserosal layer, confirming subserosal bile infiltration. Subserosal bile infiltration is a rare form of gallbladder injury; however, it may progress to bile peritonitis and should be recognized as a potential complication requiring careful attention during surgery.
Introduction
Although minimally invasive surgery (MIS) is widely used, MIS-specific complications, including gallbladder injury during urologic MIS, have been reported [1]. Subserosal bile infiltration has not been previously reported as an MIS-related gallbladder injury. We report a rare case of gallbladder subserosal bile infiltration during robot-assisted laparoscopic nephrectomy.
Case report
A 74-year-old man with diabetes underwent robot-assisted partial nephrectomy for right renal cell carcinoma. Pathology showed clear cell renal cell carcinoma (G4, pT1a) with negative margins. Two months later, contrast-enhanced computed tomography (CT) revealed a 16-mm early-enhancing nodule at the resection site, suggesting local recurrence. The gallbladder showed no remarkable CT findings.
Robot-assisted radical nephrectomy was performed transperitoneally with the patient in the left lateral position. Because of prior surgery, duodenal mobilization and adhesiolysis between the liver and anterior upper pole of the right kidney were difficult. Bleeding near the gallbladder during adhesiolysis was controlled with soft coagulation and hemostatic agents (Fig. 1a). After the inferior vena cava and left renal vein were taped, a snake retractor was used to retract the gallbladder and identify the right renal artery. Following renal vessel division and right kidney resection, dark green gallbladder discoloration was observed (Fig. 1b).
Intraoperative photographs. (a) The bleeding point at the hepatic adhesiolysis site near the gallbladder (arrowhead). Bleeding was controlled via soft coagulation. The gallbladder displayed normal coloration before retraction with a snake retractor (arrow). (b) The gallbladder after the right nephrectomy was completed. Over time, the gallbladder became dark green in color (arrow).
Video review confirmed that discoloration occurred during retraction of the snake retractor (Supplementary Video S1). Although no serosal injury or free bile spillage was seen, gallbladder injury was suspected, and laparoscopic cholecystectomy (Lap-C) was performed. Intraoperative ultrasound showed an irregular hypoechoic area in the gallbladder bed without luminal findings (Fig. 2a). Doppler ultrasound confirmed preserved right hepatic arterial flow despite concern for secondary cystic arterial flow impairment (Fig. 2b). The fragile gallbladder wall perforated easily when grasped. Intraoperative fluorescent cholangiography (IFC) showed no cystic arterial flow disturbance or bile spillage (Fig. 3a). During dissection, subserosal bile with edema was found (Fig. 3b), consistent with subserosal bile infiltration. The cystic artery was divided, and the gallbladder was removed fundus-first. Cholangiography via the cystic duct showed no bile duct injury (Fig. 3c). The cystic duct was divided, the specimen extracted, and the patient was discharged uneventfully on postoperative Day 10.
Intraoperative ultrasound. (a) An irregular hypoechoic area was observed on the gallbladder bed side. No specific findings were noted in the lumen. The arrow indicates an irregular hypoechoic area. (b) Adequate blood flow in the right hepatic artery was confirmed in Doppler mode.
Intraoperative photographs and cholangiography. (a) Cystic artery visualized using IFC. No evident impairment of cystic arterial flow and no bile leakage into the abdominal cavity was observed (arrow, cystic artery). (b) Image obtained during serosal incision of the gallbladder body. The images show edematous change caused by bile leakage within the subserosal layer; the findings are consistent with subserosal bile infiltration (arrow, bile leak within the subserosal layer). (c) Intraoperative cholangiography confirmed the absence of evident bile duct injury.
Pathology of the right renal specimen showed a 21-mm local recurrence of clear cell renal cell carcinoma with a G3 component. The gallbladder specimen showed no marked inflammation or mucosal or muscular disruption. Although hematoxylin–eosin and Hall staining showed no definite subserosal bile, nuclear loss of subserosal adipocytes on the gallbladder bed side suggested marked degeneration (Fig. 4).
Pathological findings for the gallbladder. (a) Hematoxylin–eosin staining revealed no definite bile within the subserosal layer. Loss of nuclei from subserosal adipocytes on the bed side of the gallbladder was observed. (b) Hall staining also revealed no definite bile within the subserosal layer.
Discussion
Although robotic surgery offers better visualization and dexterity than laparoscopic surgery, the reported adverse-event rates between the two are similar [2]. Approximately 85% of reported robotic-surgery adverse events are attributed to instrument or system malfunction, and 8.2% to organ injuries. In urologic robotic surgery, bowel injury is the most common organ injury (22.3%), followed by common bile duct injury (4.4%) and gallbladder injury (2.8%). Organ injury may result from energy-device thermal damage and mechanical factors, including compression, traction, and adhesiolysis [1, 3]. Although gallbladder injury during urologic MIS is poorly described, two common bile duct injuries have been reported, both occurring during adhesiolysis and retraction [4]. In this case, prior surgery required extensive adhesiolysis, and injury occurred during gallbladder retraction. These findings underscore the need for caution during adhesiolysis and retraction in MIS.
In the case of urologic MIS, the irregular hypoechoic findings on intraoperative ultrasound were attributed to subserosal bile leakage, supported by bile and edema in the gallbladder subserosa during dissection. Doppler ultrasound and IFC were performed to assess possible right hepatic or cystic arterial compromise after hemostatic manipulation; both showed preserved flow, making vascular injury unlikely. Intraoperative cholangiography showed no evident bile leakage; therefore, the injury was considered confined to the gallbladder, and Lap-C was performed. The Doppler findings, subserosal bile, and progressive color change suggest that snake-retractor compression disrupted the mucosal and muscular layers, causing subserosal bile infiltration. Although pathology showed no subserosal bile, loss of adipocyte nuclei indicated marked degeneration, supporting excessive compression as the cause.
Subserosal bile infiltration of the gallbladder is rare. One blunt-trauma case progressed to bile peritonitis, requiring emergency surgery [5]. In the present case, the changes developed gradually, and delayed recognition could have caused peritonitis; however, prompt intraoperative management prevented this. A PubMed search using “minimally invasive surgery,” “intraoperative injury,” and “subserosal bile infiltration” found no similar reports. This rare gallbladder injury may progress to bile peritonitis and should be considered during MIS, requiring extensive adhesiolysis and tissue retraction.
Author contributions
Shunryo Minezaki, Fumihiko Miura, Keisuke Ueno, Yasuyuki Ikehata, Akitoshi Nankaku, Kenji Yamazaki, Junpei Takashima, Daisuke Fujimoto, Toshihiro Kobayashi, and Minato Yokoyama participated in the treatment of the patient and reviewed the manuscript. Tatsuya Aso and Mikiko Takahashi performed the pathological examinations. Keiji Sano and Yousuke Inoue reviewed the manuscript. All the authors have read and approved the final version of the manuscript.
Conflicts of interest
The authors declare that they have no conflicts of interest.
Funding
No funding was received for this study.
Data availability
Data sharing is not applicable to this article, as no datasets were generated or analyzed during the current study.
Consent
Written informed consent for the publication of this case report and accompanying images was obtained from the patient.
