Microscope-assisted hepatic artery reconstruction in adult living donor liver transplantation-A review of 325 consecutive cases in a single center

Rates of hepatic artery thrombosis in liver transplantation with the use of a microscope: A systematic review

OBJECTIVE

Hepatic artery anastomosis in liver transplantations requires a meticulous technique to minimize the risk of hepatic artery thrombosis (HAT). The microscope helped improve anastomosis techniques in pediatric patients with small caliber vessels. The aim of this review was to compare microsurgical and non-microsurgical techniques on the incidence of HAT in liver transplantations. The secondary objective was to compare HAT incidence between pediatric and adult cohorts and between plastic and transplant surgeons.

METHODS

A systematic review of the literature using Medline, Embase, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) was conducted on studies involving HAT in liver transplantations with microsurgery. Three reviewers performed a full article review and data extraction for studies meeting the eligibility criteria of the study.

RESULTS

Forty-five studies were incorporated in the final analysis. A total of 7346 patients and 7506 liver transplants were included. The mean age was 17 years old with an equivalent distribution between pediatric (51%, n = 3218) and adult patients (49%, n = 3145). A total of 6351 of these transplantations underwent microsurgical repair, against 1157 with non-microsurgical techniques. The overall HAT rate was 4.9%, including 4.2% in the microsurgical group (n = 268) and 8.5% in the non-microsurgical group (n = 98), a statistically significant increase of 4.3%. The occurrence of HAT was 2.6% with a plastic surgeon versus 4.6% with other types of surgeons. When using microsurgical techniques, the HAT rate was 4.2% with living donors versus 7.7% with deceased donors.

CONCLUSIONS

HAT and subsequent liver transplant failure are lower when microsurgical techniques, living donors, and plastic surgeons with a microsurgical training are involved in the operation.

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.

Arterial Anastomosis Using Microsurgical Techniques in Adult Live Donor Liver Transplant: A Focus on Technique and Outcomes at a Single Institution

BACKGROUND

 Microvascular hepatic artery reconstruction (MHAR) is associated with decreased rates of hepatic artery thrombosis (HAT) in living donor liver transplantation (LDLT). There is a paucity of literature describing the learning points and initiation of this technique at the institutional level. The objective of this study is to report our institutional experience using MHAR in adult LDLT with a focus on technique and outcomes.

METHODS

 A retrospective review of adult patients who underwent LDLT from January 2012 to December 2020 was conducted. Patients were divided into two groups, those who underwent LDLT without MHAR and with MHAR. We analyzed cases for technical data including donor and recipient artery characteristics, anastomotic techniques, intraop events, and postop complications. A Mann-Whitney test was performed to compare outcomes between non-MHAR and MHAR patients.

RESULTS

 Fifty non-MHAR and 50 MHAR patients met inclusion criteria. Median age at transplantation was 58 (interquartile range [IQR] 11.8) and 57.5 years (IQR 14.5), respectively. Median follow-up for MHAR patients was 12.8 months (IQR 11.6). The most common recipient arteries were the right hepatic artery (HA) (58%) and left HA (20%). Median size of recipient and donor arteries were 3.3 mm (IQR 0.7) and 3.1 mm (IQR 0.7), resulting in a median mismatch size of 0.3 mm (IQR 0.4). Median microanastomosis time was 44 minutes (IQR 0). HAT, graft failure, and mortality rates were higher in the non-MHAR cohort (6% vs. 0%, 8% vs. 0%, and 16% vs. 6%, respectively); however, these did not reach statistical significance.

CONCLUSION

 This study found lower rates of HAT and graft failure after implementing MHAR, though statistical significance was not achieved. Larger cohort studies are needed to further assess the potential benefit of MHAR in adult LDLT. From our experience, MHAR requires cooperation between the transplant and microsurgical teams, with technical challenges overcome with appropriate instrumentation and planning.

Techniques of hepatic arterial reconstruction in liver transplantation

BACKGROUND

Hepatic artery reconstruction is an essential part of liver transplantation. This difficult stage of the operation is even more demanding in living donor liver transplantation than in deceased donor liver transplantation. One of the most important advances in hepatic artery reconstruction for living liver grafts was the introduction of microsurgical techniques involving an operative microscope or surgical loupe. Many surgical reconstruction techniques have been used in this field.

PURPOSE

In this article, first, we will talk about the hepatic artery reconstruction techniques that are frequently used in deceased donor liver transplantation, and afterward, we will talk about the hepatic artery reconstruction techniques used in living donor liver transplantation, which include the hepatic artery reconstruction technique we use and call "one stay corner suture technique".

CONCLUSIONS

We think high-volume transplant centers should tend to develop a standardized technique for doing hepatic artery reconstruction with their teams. We think the "one stay corner suture technique" can be easily applied in centers that perform LDLT.

A review of split liver transplantation with full right/left hemi-liver grafts for 2 adult recipients

Liver transplantation has become a routine operation in many transplantation centers worldwide. However, liver graft availability fails to meet patient demands. Split liver transplantation (SPLT), which divides a deceased donor liver into 2 partial liver grafts, is a promising strategy for increasing graft availability for transplantation and ameliorating organ shortage to a certain degree. However, the transplantation community has not yet reached a consensus on SPLT because of the variable results. Specifically, SPLT for 2 adult recipients using full right/left hemi-liver grafts is clinically more challenging in terms of surgical technique and potential postoperative complications. Therefore, this review summarizes the current status of SPLT, focusing on the transplantation of adult recipients. Furthermore, the initiation of the SPLT program, donor allocation, surgical aspects, recipient outcomes, and obstacles to developing this procedure will be thoroughly discussed. This information might help provide an optimal strategy for implementing SPLT for 2 adult recipients among current transplantation societies. Meanwhile, potential obstacles to SPLT might be overcome in the near future with growing knowledge, experience, and refinement of surgical techniques. Ultimately, the widespread diffusion of SPLT may increase graft availability and mitigate organ donation shortages.

Microscope-Assisted Arterial Anastomosis in Adult Living Donor Liver Transplantation: A Systematic Review and Meta-analysis of Outcomes

BACKGROUND

 Living donor liver transplantation (LDLT) has expanded the availability of liver transplant but has been associated with early technical complications including the devastating complication of hepatic artery thrombosis (HAT), which has been reported to occur in 14% to 25% of LDLT using standard anastomotic techniques. Microvascular hepatic artery reconstruction (MHAR) has been implemented in an attempt to decrease rates of HAT. The purpose of this study was to review the available literature in LDLT, specifically related to MHAR to determine its impact on rates of posttransplant complications including HAT.

METHODS

 A systematic review was conducted using PubMed/Medline and Web of Science. Case series and reviews describing reports of microscope-assisted hepatic artery anastomosis in adult patients were considered for meta-analysis of factors contributing to HAT.

RESULTS

 In all, 462 abstracts were screened, resulting in 20 studies that were included in the meta-analysis. This analysis included 2,457 patients from eight countries. The pooled rate of HAT was 2.20% with an overall effect size of 0.00906.

CONCLUSION

 Systematic literature review suggests that MHAR during LDLT reduces vascular complications and improves outcomes posttransplant. Microvascular surgeons and transplant surgeons should collaborate when technical challenges such as small vessel size, short donor pedicle, or dissection of the recipient vessel wall are present.

Meta-analysis and meta-regression of outcomes for adult living donor liver transplantation versus deceased donor liver transplantation

Prior single center or registry studies have shown that living donor liver transplantation (LDLT) decreases waitlist mortality and offers superior patient survival over deceased donor liver transplantation (DDLT). The aim of this study was to compare outcomes for adult LDLT and DDLT via systematic review. A meta-analysis was conducted to examine patient survival and graft survival, MELD, waiting time, technical complications, and postoperative infections. Out of 8600 abstracts, 19 international studies comparing adult LDLT and DDLT published between 1/2005 and 12/2017 were included. U.S. outcomes were analyzed using registry data. Overall, 4571 LDLT and 66,826 DDLT patients were examined. LDLT was associated with lower mortality at 1, 3, and 5 years posttransplant (5-year HR 0.87 [95% CI 0.81-0.93], p < .0001), similar graft survival, lower MELD at transplant (p < .04), shorter waiting time (p < .0001), and lower risk of rejection (p = .02), with a higher risk of biliary complications (OR 2.14, p < .0001). No differences were observed in rates of hepatic artery thrombosis. In meta-regression analysis, MELD difference was significantly associated with posttransplant survival (R² 0.56, p = .02). In conclusion, LDLT is associated with improved patient survival, less waiting time, and lower MELD at LT, despite posing a higher risk of biliary complications that did not affect survival posttransplant.

Assessment of the global practice of living donor liver transplantation

Criteria that drive the selection and utilization of living liver donors are limited. Herein, the global availability of living donor liver transplantation (LDLT) and components of donor selection and utilization were assessed via an international survey. There were 124 respondents representing 41 countries, including 47 from Asia/Middle East (A/ME), 20 from Europe, and 57 from the Americas. Responses were obtained from 94.9% of countries with ≥10 LDLT cases/year. Most centers (82.3%) have defined donor age criteria (median 18-60 years), while preset recipient MELD cutoffs (median 18-30) were only reported in 54.8% of programs. Overall, 67.5% of programs have preset donor BMI (body mass index) ranges (median 18-30), and the mean acceptable macrosteatosis was highest for A/ME (20.2 ± 9.2%) and lowest for Americas (16.5 ± 8.4%, P = 0.04). Americas (56.1%) and European (60.0%) programs were more likely to consider anonymous donors versus A/ME programs (27.7%, P = 0.01). There were no differences in consideration of complex anatomical variations. Most programs (75.9%) perform donor surgery via an open approach, and A/ME programs are more likely to use microscopic arterial reconstruction. Despite variations in practice, key aspects of living donor selection were identified. These findings provide a contemporary reference point as LDLT continues to expand into areas with limited access to liver transplantation.

Microsurgical Hepatic Artery Reconstruction in Deceased Donor Liver Transplantation for Reduced Arterial Complications

Aberrant donor hepatic artery anatomy or hepatic artery injury during organ procurement or recipient preparation poses a surgical challenge during deceased donor liver transplantation. In this study, we aimed to investigate arterial reconstruction using microvascular techniques during deceased donor liver transplantation and suggest reasonable indications for the microsurgical approach in this setting. We retrospectively reviewed the outcomes of 470 deceased donor liver transplantations performed at our institution between July 2011 and December 2015. Of these, 128 recipients underwent microsurgical hepatic artery reconstruction and 342 underwent reconstruction with surgical loupes. Thirty-two patients (6.8%) experienced hepatic artery-related complications, including hepatic artery thrombosis (n = 8, 1.7%). In the propensity score-matched cohort, the surgical loupe group showed a higher complication rate (P = .782). On multivariate analysis, cold ischemia time (odds ratio, 0.995; 95% confidence interval, 0.9920-0.999; P = .009) and use of aortohepatic conduits (odds ratio, 5.254; 95% confidence interval, 1.878-14.699; P = .002) were independent predictors of arterial complications. The low incidence of hepatic artery complications in this study is likely attributable to the active application of microsurgical techniques. Active application of back-table microsurgical plasty and selective application of microsurgical techniques for main arterial reconstruction may help minimize operative difficulties and arterial complications.

Comprehensive review of surgical microscopes: technology development and medical applications

SIGNIFICANCE

Surgical microscopes provide adjustable magnification, bright illumination, and clear visualization of the surgical field and have been increasingly used in operating rooms. State-of-the-art surgical microscopes are integrated with various imaging modalities, such as optical coherence tomography (OCT), fluorescence imaging, and augmented reality (AR) for image-guided surgery.

AIM

This comprehensive review is based on the literature of over 500 papers that cover the technology development and applications of surgical microscopy over the past century. The aim of this review is threefold: (i) providing a comprehensive technical overview of surgical microscopes, (ii) providing critical references for microscope selection and system development, and (iii) providing an overview of various medical applications.

APPROACH

More than 500 references were collected and reviewed. A timeline of important milestones during the evolution of surgical microscope is provided in this study. An in-depth technical overview of the optical system, mechanical system, illumination, visualization, and integration with advanced imaging modalities is provided. Various medical applications of surgical microscopes in neurosurgery and spine surgery, ophthalmic surgery, ear-nose-throat (ENT) surgery, endodontics, and plastic and reconstructive surgery are described.

RESULTS

Surgical microscopy has been significantly advanced in the technical aspects of high-end optics, bright and shadow-free illumination, stable and flexible mechanical design, and versatile visualization. New imaging modalities, such as hyperspectral imaging, OCT, fluorescence imaging, photoacoustic microscopy, and laser speckle contrast imaging, are being integrated with surgical microscopes. Advanced visualization and AR are being added to surgical microscopes as new features that are changing clinical practices in the operating room.

CONCLUSIONS

The combination of new imaging technologies and surgical microscopy will enable surgeons to perform challenging procedures and improve surgical outcomes. With advanced visualization and improved ergonomics, the surgical microscope has become a powerful tool in neurosurgery, spinal, ENT, ophthalmic, plastic and reconstructive surgeries.

Impact of Microsurgical Anastomosis of Hepatic Artery on Arterial Complications and Survival Outcomes After Liver Transplantation

Hepatic artery (HA) complications after liver transplant (LT) can lead to biliary complications, graft failure, and mortality. Although microsurgery has been established to improve anastomotic outcomes, it prolongs surgical time and has not reached widespread adoption at all transplant centers. We investigated the incidences of arterial, biliary complications and outcomes after using microsurgery to anastomose HA during LT. Retrospective cohort of consecutive LT performed from 2006 to 2018 was reviewed for operative details and postoperative outcomes. Cox-regression models were used to investigate the relationship between variables and outcomes. Eighty (62.5%) LTs (Group 1) were performed without and compared with 48 (Group 2) with microsurgical anastomosis of HA. Both groups were comparable in terms of arterial and biliary anastomoses performed. Incidence of early HA thrombosis was similar (6.2% vs 2.1%, P = .28). Group 2 had lower incidence of short- and long-term arterial complications, especially amongst living donor liver transplantations (LDLT) (5.3% vs 35.0%, P = .022). On multivariate analysis, microsurgery was associated with lower risk (hazard ratio [HR] 0.09, 95% confidence interval [CI] 0.01-0.71) of, and LDLT had higher risk (HR 4.23, 95% CI 1.46-12.27) of arterial complications. Biliary complications were associated with LDLT (HR 3.91, 95% CI 1.30-11.71) and dual biliary anastomoses (HR 5.26, 95% CI 1.15-24.08) but not with occurrence of HA complications. Worse patient survival was associated with the occurrence of any HA complication (HR 4.11, 95% CI 1.78-9.48). Hepatic arterial complications can be reduced using microsurgical techniques for the anastomosis, resulting in improved patient survival outcomes after liver transplantation.

What happened in 133 consecutive hepatic artery reconstruction in liver transplantation in 1 year?

Background

The immediate challenges during microvascular reconstruction of hepatic artery (HAR) during liver transplantation (LT) can be many. Hence, in order to give a cross sectional view of these problems this study over a period of 1 year, showing our routine practice, was taken up.

Methods

From January 2015 to December 2015, a total of 133 LTs were performed in Kaohsiung Chang Gung Memorial Hospital, Taiwan. All hepatic artery (HA) reconstructions were performed by a microvascular surgeon under an operating microscope.

Results

In the 133 patients, one artery was anastomosed in 123 (92.5%) patients, two in 9 (6.8%) patients and three in 1 (0.7%) of the patient. Eleven (8.3%) arteries were less than 2 mm in size (1-1.9 mm). There were intimal dissections (IDs) involving either the donor or the recipient arteries of mild to severe nature in 9 (6.8%) patients. Immediately following graft arterial anastomosis, either there was no flow or an intraoperative hepatic artery thrombosis (HAT) was found in nine (7.1%-8 LDLT, 4.8%-1 DDLT) patients. Immediate re-do anastomosis was done in all of these patients who did well in the follow-up. The overall post-operative success rate was 99.2%. One patient (0.8%) developed postoperative HAT due to infection during follow up and died due to sepsis.

Conclusions

Small vessels or HA injury are the frequently encountered problems by a micro vascular surgeon. The other problems could be ID, need to do multiple reconstructions, immediate HAT and ability to re-do the HAR immediately.