Anatomical Basis for Selective Multiple Arterial Reconstructions in Living Donor Liver Transplantation

A novel arterial coupler with non-return snap-fit connection approach optimized arterial end-to-end anastomotic technique: An experimental study

PURPOSE

Hand-sewn anastomosis as the gold standard of vascular anastomosis cannot fully meet the requirements of vascular anastomosis in speed and quality. Various vascular couplers have been developed to ameliorate this situation. Most of them are mainly used for venous anastomosis rather than arterial anastomosis. Although it is generally acknowledged that in almost all operations involving vascular reconstruction, it is the arteries that need to be anastomosed faster and more accurately and not the veins. A dedicated device is needed for creating arterial anastomosis in an easy, timesaving, less damaging but reliable procedure. Therefore, we plan to develop a novel arterial coupler device and test pre-clinical safety and effectiveness.

METHODS

In this cohort study, the rationality of this novel arterial coupler was preliminarily tested by finite element analysis before it was manufactured. Several factors restrict the use of vascular couplers in arterial anastomosis, such as arterial eversion, fixation, etc. The manufactured arterial couplers underwent in vitro and in vivo experiments. In vitro, isolated arteries of beagles were anastomosed with the assistance of an arterial coupler, and the anastomosed arteries were evaluated through anti-traction tests. In animal experiments, the bilateral femoral arteries of 5 beagles served as a control group. After dissection, the femoral artery on one side was randomly selected to be anastomosed with a quick arterial coupler (QAC) (QAC group), and the femoral artery on the other side was anastomosed by the same person using an end-to-end suture technique with a 6-0 Prolene suture (suture group). The bilateral femoral arteries of 5 beagles were used for coupler-assisted anastomosis and hand-sewn anastomosis in vivo, respectively. Success rate, blood loss, anastomotic time, clamp time, total operation time, and patency rate were recorded. The patency of anastomosed arteries was assessed using vascular Doppler ultrasound, electromagnetic flowmeter, and pathological examination (6 weeks after surgery).

RESULTS

As a novel arterial coupler, QAC was successfully designed and manufactured by using poly lactic-co-glycolic acid raw materials and 3-dimensions printing technology. Its rationality was preliminarily tested through finite element analysis and related mechanical analysis methods. The isolated arteries were successfully anastomosed with the assistance of QAC in vitro testing, which showed good anti-traction properties. In animal studies, QAC-assisted arterial anastomosis has superior profiles compared to hand-sewn anastomosis in anastomotic time (7.80 ± 1.41 vs. 16.38 ± 1.04 min), clamp time (8.80 ± 1.41 vs. 14.14 ± 1.57 min), and total operation time (46.64 ± 2.38 vs. 51.96 ± 3.65 min). The results of electromagnetic flowmeter, vascular Doppler ultrasound, and pathological examination showed that QAC-assisted anastomotic arteries were superior to hand-sewn arteries in terms of postoperative blood flow (16.86 ± 3.93 vs. 10.36 ± 0.92 mL/min) and vascular patency in 6 weeks after surgery.

CONCLUSION

QAC is a well-designed and easily maneuverable device specialized for end-to-end arterial anastomosis. Application of this device may decrease thermal ischemia time and improve the patency of anastomotic arteries, thus, improving outcomes.

Reconstruction of all hepatic arteries in right lobe grafts with 2 hepatic arteries and zero percent hepatic artery thrombosis

Hepatic artery thrombosis (HAT) is a common cause of graft loss in living-donor liver transplantation, occurring in ~2.5%-8% of patients. Some right lobe grafts have 2 hepatic arteries (HAs), and the optimal reconstruction technique remains controversial. This study aimed to identify risk factors for HAT and to evaluate the efficacy of reconstructing 2 HAs in right lobe grafts. This retrospective, single-center study analyzed 1601 living-donor liver transplantation recipients with a right liver graft and divided them into 1 HA (n = 1524) and 2 HA (n = 77) groups. The reconstruction of all HAs was performed using a microscope with an interrupted suture. The primary outcome was any HAT event. Of the 1601 patients, 37.8% had a history of transcatheter arterial chemoembolization, and 130 underwent pretransplant hepatectomy. Extra-anatomical arterial reconstruction was performed in 38 cases (2.4%). HAT occurred in 1.2% of patients (20/1601) who underwent surgical revascularization. In the multivariate analysis, undergoing pretransplant hepatectomy ( p = 0.008), having a female donor ( p = 0.02), having a smaller graft-to-recipient weight ratio ( p = 0.002), and undergoing extra-anatomical reconstruction ( p = 0.001) were identified as risk factors for HAT. However, having 2 HA openings in right liver grafts was not a risk factor for HAT in our series. Kaplan-Meier survival analysis showed no significant difference in graft survival and patient survival rates between the 1 HA and 2 HA groups ( p = 0.09, p = 0.97). In our series, although the smaller HA in the 2 HA group should increase the risk of HAT, HAT did not occur in this group. Therefore, reconstructing both HAs when possible may be a reasonable approach in living-donor liver transplantation using a right liver graft with 2 HA openings.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Technique of Hepatic Artery Anastomosis in Living Donor Liver Transplantation: Review of Its Results in Over 1200 Adult and Pediatric Transplants

BACKGROUND

Failure to achieve a good arterial inflow to the graft in living donor liver transplantation (LDLT) has disastrous consequences to the graft and patient survival. Standard microvascular techniques of hepatic artery (HA) anastomosis used in deceased donor liver transplantation are not applicable in LDLT. We present the results of our unique Backwall-first technique of HA anastomosis in both adult and pediatric LDLT.

PATIENTS AND METHODS

Retrospective review of all consecutive patients who underwent LDLT from January 2010 to December 2020 was performed from our prospective database. Data with regard to early postoperative (90-day) hepatic arterial complications were analyzed.

RESULTS

A total of 1276 LDLTs (876 adults, 400 children) were performed during the study period. In the 90-day postoperative period, HA anastomotic complications [thrombosis in 11 (0.9%); pseudoaneurysm in 3 (0.2%)] were observed in 14 recipients (1.1%) including 8 adults (0.9%) and 6 children (1.5%). Eight of these 14 recipients (0.6%) including 4 adults (0.5%) and 4 children (1%) had standard HA reconstruction. The remaining six (0.5%) including 4 adults and 2 children had complex arterial reconstruction with interposition graft and/or alternative arterial inflow.

CONCLUSION

The Backwall-first technique of HA reconstruction described in this study achieved a very low HA complication rate in LDLT.