Vascular Division Techniques in Minimally Invasive Living Donor Hepatectomy
Direct Answer
In minimally invasive living donor right hepatectomy, the hepatic artery, portal vein, and right hepatic vein should be meticulously dissected extracorporeally during hilar dissection, ligated and transected after parenchymal division is complete, with the right hepatic vein divided using laparoscopic linear cutting staplers, while graft extraction occurs through a mini-laparotomy or hand-port site. 1, 2, 3
Technical Approach to Vascular Division
Hepatic Artery Division
The right hepatic artery requires meticulous dissection and encirclement with vessel loops during the hilar dissection phase before parenchymal transection begins. 2, 4
The artery is typically ligated and transected after parenchymal division is completed, with careful attention to aberrant hepatic arterial anatomy identified preoperatively. 1
Arterial anastomoses in living donor hepatectomy are particularly challenging due to their small diameter (3-4 mm), requiring precise surgical technique. 1
Portal Vein Division
The right portal vein should be dissected and encircled with vessel loops during initial hilar dissection, then ligated and transected after completion of parenchymal transection. 2, 4
An alternative simplified approach exists where intraparenchymal transection of the right pedicle (including portal vein) can be performed without prior hilar dissection, guided by ultrasound definition of the transection line. 5
This ultrasound-guided approach showed comparable outcomes with median operative time of 310 minutes versus 338 minutes for standard technique, though this represents a departure from traditional methodology. 5
Right Hepatic Vein Division
The right hepatic vein should be transected using a laparoscopic linear cutting stapler after parenchymal transection is complete, representing the final step before graft extraction. 3
Major middle hepatic vein branches (>5 mm) should be preserved using Hem-o-lock clips during parenchymal transection when performing modified right hepatectomy. 4
Short hepatic veins require special attention—if the orifice diameter exceeds 0.5 cm on the graft cutting surface, venous outflow tract reconstruction using cadaveric vascular allograft is necessary. 3
Parenchymal Transection Methodology
Liver parenchymal transection should be performed using an alternating combination of laparoscopic ultrasonic aspirator (CUSA) and energy devices like THUNDERBEAT, with Pringle's maneuver applied during transection. 2
The transection can be performed either under pneumoperitoneum in total laparoscopic approaches or through a mini-laparotomy incision (10 cm upper midline) in hybrid techniques. 2, 6
Ultrasonic aspirator use without Pringle maneuver has been reported in some series, though this represents a less common approach. 4
Critical Anatomical Considerations
Preoperative Planning
Careful interrogation of aberrant hepatic arterial anatomy must be performed preoperatively to prevent vascular complications. 1
Preoperative imaging should assess patency of hepatic veins and their anatomical relations, with particular attention to middle hepatic vein tributaries. 1, 4
The minimum graft size must be at least 0.8% of recipient body weight to ensure viability. 1
Bile Duct Management
Intraoperative cholangiography using mobile C-arm should be performed before dividing the left bile duct to prevent injury to segmental bile ducts. 2
Liberal use of cholangiograms and bile leak tests is recommended to prevent bile duct complications, which represent the most common donor complication. 1
Bile leaks occurred in 0% of cases using ultrasound-guided technique versus 28% with standard hilar dissection in one comparative series, suggesting potential benefit of modified approaches. 5
Graft Extraction
The graft should be extracted through the hand-port device site or mini-laparotomy incision after all vascular and biliary structures are divided. 4, 3
Back-table reconstruction of middle hepatic vein branches can be performed using artificial vascular grafts when preservation of these branches is necessary. 4
Warm ischemia time should be minimized, with reported times as low as 4 minutes in experienced centers. 3
Operative Outcomes and Safety
Morbidity Considerations
Approximately one-third of living donors experience complications, with the majority being Clavien-Dindo type I or II, and right lobe donors have significantly higher complication rates than left lobe donors. 1
Minimally invasive approaches demonstrate reduced blood loss (212 mL versus 316 mL for open) and shorter hospital stays (5.9 versus 7.8 days) without compromising safety. 6
Donor mortality risk is estimated at 0.18%, though this may be under-reported, with major hemorrhage (0.06%) representing the primary cause. 1
Technical Feasibility
Total laparoscopic living donor right hepatectomy should only be performed in transplant centers with extensive open living donor experience and skilled laparoscopic techniques. 3
Operative times range from 300-480 minutes for total laparoscopic approaches and 310-575 minutes for laparoscopy-assisted techniques. 2, 4
Blood loss can be maintained under 125-300 mL without transfusion in experienced hands. 2, 3
Critical Pitfalls to Avoid
Avoid dissection about the hilum in patients with complex vascular anatomy—consider ultrasound-guided intraparenchymal division as an alternative. 5
Do not proceed without identifying and preserving middle hepatic vein tributaries greater than 5 mm, as inadequate venous outflow can compromise graft function. 4, 3
Never divide the bile duct without intraoperative cholangiography, as bile duct injury can result in interstage sepsis and donor morbidity. 1, 2
Ensure adequate graft size calculation preoperatively—grafts below 0.8% of recipient body weight risk post-transplant hepatic failure. 1