Microvascular Hepatic Artery Anastomosis in Pediatric Living Donor Liver Transplantation: 73 Consecutive Cases Performed by a Single Surgeon

Systematic Review and Meta-Analysis of the Outcomes After Hepatic Artery Reconstruction in Pediatric Liver Transplantation Using a Microscope Versus Surgical Loupe

BACKGROUND

To review the impact of the operating microscope (OM) for reconstruction of the hepatic artery (HA) by comparing the outcomes with standard loupe reconstruction (SL) in pediatric liver transplantation (LT).

METHODS

Studies comparing the application of OM and SL for the reconstruction of the HA in primary pediatric LT were included from a systematic search of MEDLINE, Cochrane Library and EMBASE from inception to June 2022. Re-transplantation, dual grafts and auxiliary transplants were excluded. Primary outcome was the rate of HA thrombosis (HAT). Secondary outcomes were graft loss and mortality.

RESULTS

There were 1261 liver recipients from 9 included studies published until June 2022. There were 484 patients in the OM group and 777 patients in the SL group. HAT incidence with OM was significantly lower with OR = 0.18 (95% CI: 0.07-0.48). The 1-year graft survival was significantly better in the OM group with OR = 2.77 (95% CI: 1.13-6.80). 1-year overall mortality was also significantly lower with OM with OR = 0.39 (0.18-0.86). The use of OM did not significantly impact the incidence of HAT in the living donor liver transplant subgroup. Differences in time for hepatic HA reconstruction, total operating time and length of hospital stay did not reach statistical significance.

CONCLUSION

The use of OM has reduced the risk of HAT, graft loss and mortality in pediatric liver transplantation. Adoption of microsurgical principles in general may have contributed to the improved outcomes with SL reconstruction of HA in pediatric LT.

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.

Simple Separate Sutures Versus Continuous Sutures on Hepatic Artery Anastomosis in Liver Transplant: A Prospective Study

OBJECTIVES

Liver transplant is the definitive treatment for liver failure of various causes. There are various operation methods, of which the conventional approach is most frequently performed. In the conventional technique, 4 anastomoses are required, and different subtleties in these techniques are known to cause different rates of complications. We assessed the outcome of a simple separate (ie, interrupted) suture technique compared with a the continuous suture technique in 194 patients.

MATERIALS AND METHODS

There were 194 patients included in this single-center, controlled study. The exclusion criteria were patients who died during the surgical procedure and patients with incomplete medical records. The data recorded were age, sex, past medical history of liver disease, tobacco use, comorbidities, and whetherthe livertransplant was for the first time or retransplant. All patients included in this study were recipients of liver transplants from deceased donors. The patients were categorized as those who received either simple sutures (n = 16) or continuous sutures (n = 178). The continuous suture operations were performed first, and the simple suture operations were performed at a later time (ie, the 2 groups were temporally separated). The results included the duration of surgery, hepatic artery thrombosis rate, hepatic artery stenosis rate, 2-year survival, and further complications.

RESULTS

No evidence of hepatic artery thrombosis or hepatic artery stenosis was observed in the study groups. The duration of surgery was equal in both groups. The 2-year mortality rate was significantly higher in the simple suture group.

CONCLUSIONS

The continuous suture method seems to be accompanied by a similar duration of operation and rate of complications compared with the simple suture process.

Effect of magnification in pediatric liver transplantation: A systematic review and meta-analysis

BACKGROUND

Hepatic artery thrombosis (HAT) represents a devastating and often fatal complication of liver transplantation. Due to the small vessel caliber in pediatric patients, the use of an operating microscope has largely become the standard for hepatic artery reconstruction to reduce the rate of HAT. Recent evidence, however, suggests that loupe magnification for anastomosis may be equally effective. We aimed to determine the effect of magnification on the rate of hepatic artery thrombosis in pediatric liver transplantation.

METHODS

A systematic search of the literature was conducted. Thousand eighty-eight unique titles were assessed by two independent reviewers. Studies directly comparing rates of HAT from loupe magnification and operating microscope-assisted anastomoses were eligible for meta-analysis.

RESULTS

Among primary transplants, the rate of HAT was 6.0%. Operating microscope anastomosis was associated with a 2.6% decrease in the rate of HAT compared to that of loupe magnification (4.9% and 7.4%, respectively, p < .040). When re-transplants were included, the rate of HAT was 5.8%. Operating microscope anastomosis was associated with a 1.0% decrease in the rate of HAT compared to that of loupe magnification (5.3% and 6.3%, respectively, p < .279). Meta-analysis of eligible studies demonstrated a reduction in the rate of HAT with the use of an operating microscope (p < .03).

CONCLUSIONS

Anastomosis under an operating microscope may be associated with decreased rates of HAT in children undergoing primary liver transplantation. Further high-quality studies comparing the two techniques are needed.

Hepatic artery reconstruction using an operating microscope in pediatric liver transplantation-Is it worth the effort?

INTRODUCTION

In pediatric liver transplantation (pLT), hepatic artery thrombosis (HAT) is associated with inferior transplant outcome. Hepatic artery reconstruction (HAR) using an operating microscope (OM) is considered to reduce the incidence of HAT.

METHODS

HAR using an OM was compared to a historic cohort using surgical loupes (SL) in pLT performed between 2009 and 2020. Primary endpoint was the occurrence of HAT. Secondary endpoints were 1-year patient and graft survival determined by Kaplan-Meier analysis and complications. Multivariate analysis was used to identify independent risk factors for HAT and adverse events.

RESULTS

A total of 79 pLTs were performed [30 (38.0%) living donations; 49 (62.0%) postmortem donations] divided into 23 (29.1%) segment 2/3, 32 (40.5%) left lobe, 4 (5.1%) extended right lobe, and 20 (25.3%) full-size grafts. One-year patient and graft survival were both 95.2% in the OM group versus 86.2% and 77.8% in the SL group (p = .276 and p = .077). HAT rate was 0% in the OM group versus 24.1% in the SL group (p = .013). One-year patient and graft survival were 64.3% and 35.7% in patient with HAT, compared to 93.9% and 92.8% in patients with no HAT (both p < .001). Multivariate analysis revealed HAR with SL (p = .022) and deceased donor liver transplantation (DDLT) (p = .014) as independent risk factors for HAT. The occurrence of HAT was independently associated with the need for retransplantation (p < .001) and biliary leakage (p = .045).

CONCLUSION

In pLT, the use of an OM is significantly associated to reduce HAT rate, biliary complications, and graft loss and outweighs the disadvantages of delayed arterial perfusion and prolonged warm ischemia time (WIT).

Microsurgical and Endovascular Management of Congenital Iliac Aneurysms in the Neonatal Period: Two Cases and a Literature Review

Introduction

Congenital aneurysms of major arteries are very rare diagnoses and prognosis can be poor if treatment is not initiated rapidly. This is the presentation of two cases of infants with congenital iliac aneurysms who underwent treatment in the neonatal period. The report then proceeds with a literature review of paediatric iliac aneurysms.

Report

Case 1: A female neonate was diagnosed antenatally with right common iliac (CIA) and internal iliac (IIA) artery aneurysms. Embolisation on day of life (DOL) eight was impossible because of partial thrombosis. The infant was subsequently observed for several months and the aneurysm was injected percutaneously with thrombin on DOL 78. A small residual aneurysm was coil embolised at five months of age. Satisfactory results were observed at one year follow up. Case 2: A female neonate was diagnosed antenatally on routine third trimester ultrasound with voluminous, bilateral CIA aneurysms. The patient underwent surgery on DOL 9 for aneurysm resection and microsurgical vascular reconstruction. The intervention was successful with triphasic flow through the anastomoses on colour Doppler ultrasound at six week follow up.

Discussion

Ten cases of congenital iliac aneurysms have been reported previously, with just two diagnosed in the neonatal period and eight undergoing surgical intervention. Definitive management to avoid aneurysm rupture or thrombosis should be timed carefully, and sometimes delayed with watchful waiting, to maximise success and minimise complications. Surgery is the key treatment modality, but endovascular intervention can be considered in selected cases. Congenital iliac aneurysms should be addressed at the safest time for the patient. Following resection, primary microvascular anastomosis is the ideal reconstructive technique, but other options for neonates have been described. Endovascular treatment should be considered for anatomically amenable saccular aneurysms.

The Transition to Microsurgical Technique for Hepatic Artery Reconstruction in Pediatric Liver Transplantation

BACKGROUND

Hepatic artery thrombosis represents a potentially fatal complication following liver transplantation. Rates of hepatic artery thrombosis are significantly higher in children, with mortality reported up to 80 percent. Microsurgical anastomosis has been shown to decrease the rate of hepatic artery thrombosis and now represents the standard of care at the authors' institution. In this article, the authors present the largest study of its type directly comparing rates of hepatic artery thrombosis with and without microsurgical reconstruction of the hepatic artery.

METHODS

All pediatric patients who underwent primary orthotopic liver transplantation between 1989 and 2018 were included. Patients were divided into two cohorts: standard anastomosis with loupes, and microsurgical anastomosis under the operating microscope. The authors' primary outcome was the rate of hepatic artery thrombosis. Secondary outcomes were graft survival, patient survival, retransplantation rate, requirement for intraoperative blood products, and length of stay.

RESULTS

Two hundred thirty-one children met criteria for inclusion. One hundred eighty cases were performed with loupe magnification and 51 cases were performed under the microscope. The hepatic artery thrombosis rate was lower, but not significantly so (p = 0.114), in the microsurgical group [n = 1 (2.0 percent)] compared with the standard cohort [n = 15 (8.3 percent)]. Survival analysis revealed a significant increase in graft survival with microsurgical anastomosis (p = 0.020), but not patient survival (p = 0.196). The retransplantation rate was significantly lower with microsurgical anastomosis (p = 0.021).

CONCLUSIONS

Microsurgical anastomosis was associated with a clinically important decrease in hepatic artery thrombosis compared with standard loupe anastomosis. The graft survival rate was significantly higher in the microsurgical cohort, with a reduced retransplantation rate at 1 year. On this basis, the authors recommend microsurgical hepatic artery anastomosis in cases of pediatric liver transplantation. .

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Neonatal Microsurgical Repair of a Congenital Abdominal Aortic Aneurysm with a Cadaveric Graft

Congenital abdominal aortic aneurysms (AAA) are an extremely rare entity. We present the case of a female fetus diagnosed with an AAA on routine prenatal ultrasound. A postnatal computed tomography angiogram revealed an infrarenal AAA with a narrow proximal neck. Surgery was performed on day of life 14 using a cadaveric femoral artery graft. The proximal anastomosis was performed under the microscope given the severity of the aortic stenosis and the proximity of the renal arteries. The patient's postoperative course was uneventful and she is developing normally 1 year after surgery. The graft remains permeable, albeit with evidence of proximal and distal stenosis and graft calcification on imaging.

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.

Hepatic Artery Microvascular Anastomosis in Liver Transplantation: A Systematic Review of the Literature

BACKGROUND

The operating microscope is used in many centers for microvascular hepatic arterial reconstruction in living as well as deceased donor liver transplantation in adult and pediatric recipients. To date, a systematic review of the literature examining this topic is lacking.

METHODS

This systematic review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Three different electronic databases (PubMed, Embase OVID, and Cochrane CENTRAL) were queried.

RESULTS

A total of 34 studies were included. The rate of hepatic artery thrombosis (HAT) in noncomparative studies (28) ranged from 0% to 10%, with 8 studies reporting patient deaths resulting from HAT. Within comparative studies, the rate of HAT in patients who underwent arterial reconstruction using the operating microscope ranged from 0% to 5.3%, whereas the rate of HAT in patients who underwent arterial reconstruction using loupe magnification ranged from 0% up to 28.6%, and 2 studies reported patient deaths resulting from HAT. Two comparative studies did not find statistically significant differences between the 2 groups.

CONCLUSIONS

Our comprehensive systematic review of the literature seems to suggest that overall, rates of HAT may be lower when the operating microscope is used for hepatic arterial reconstruction in liver transplantation. However, matched comparisons are lacking and surgical teams need to be mindful of the learning curve associated with the use of the operating microscope as compared with loupe magnification, as well as the logistical and time constraints associated with setup of the operating microscope.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.

Usefulness of microsurgical back-table angioplasty for multiple hepatic arteries in living donor liver transplantation

The graft hepatic artery orifice is tiny in living donor liver transplantation, and therefore, it is more difficult to reconstruct the hepatic artery than in deceased donor liver transplantation. In situ, multi-vessel hepatic artery reconstruction in living donor liver transplantation is time-consuming, and reconstructions are often complicated if the hepatic graft has several stumps. We describe two living donor liver transplants using back-table microsurgical angioplasty to combine two hepatic artery stumps to create a single orifice, and sequential single-vessel hepatic artery reconstruction in the recipient. Briefly, we used double-needle interrupted sutures for the two hepatic artery stumps with a biangular stay-suture method in back-table microsurgical angioplasty. Each suture was placed from the inner side of the arterial wall to the outer side, which allowed for safe and reliable suturing. After placing the interrupted sutures in the anterior wall, we turned over the vessels in the cold storage on the back table and placed interrupted sutures in the posterior wall. In the recipient, the single stump of the graft was anastomosed to the recipient's hepatic artery using an interrupted pattern and a surgical microscope. The postoperative courses of the donors and recipients were uneventful. Back-table hepatic artery angioplasty is a feasible option to overcome the complexities of multi-vessel arterial reconstruction in living donor liver transplantation. We recommend performing secure multi-vessel hepatic arterial reconstruction adapted to the clinical scenario. Using simple appropriate anastomosis, back-table microsurgical angiography may provide good results in living donor liver transplantation.

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.

Multiple Thrombi during Microvascular Anastomosis Caused by Decreased Antithrombin Activity: A Case Report

With recent advances in microsurgical instruments and technique, microvascular anastomosis has become a universal surgical technique; however, thrombosis still presents in a number of cases. Tension, twisting, and compression to the anastomotic site are the main causes of thrombus; however, disorder of the coagulation-fibrinolysis system also need to be considered. To date, only few reports exist regarding thrombosis caused by disorder of coagulant system in microvascular anastomosis. Here we report our 3 cases in which multiple thrombus formation occurred intraoperatively caused by decrease of antithrombin (AT) activity. AT activity was measured twice a day after vascular anastomosis: after surgery and up to 3 days after surgery. Thrombosis was not observed in any of the 3 patients intraoperatively after the transfusion, or thrombosis was not observed in any of 3 patients intraoperatively after the transfusion or postoperatively, and no other complications were observed. In these 3 cases, the thrombus was not caused by technical error or other previously described factors. The observed intraoperative decrease in AT activity was thought to be caused by thrombus formation. It is important that microsurgeons are reminded that disorders of the coagulation-fibrinolysis system could cause thrombosis.

Microsurgical Salvage of Acute Lower Limb Ischemia after Iatrogenic Femoral Injury during Orthopedic Surgery in a Pediatric Patient

Acute lower limb ischemia (ALLI) in the pediatric population is rare but may lead to limb loss and life-long complications. We report the technique and outcomes of microsurgical salvage of ALLI in a preterm newborn after open reduction of congenital hip dysplasia. A 2-month-old girl was born premature at week 36 with congenital bilateral hip dysplasia. The initial management attempted was conservative and entailed placement of bilateral Von Rosen splints. The treatment was successful on the left side, but the patient had recurrent unstable hip dislocation on the right side. Subsequently, 2 attempts at close reduction under general anesthesia were done and both were unsuccessful in maintaining the right hip in the acetabulum. Therefore, an open reduction of the right hip was planned through a medial/obturator approach. During the surgical procedure, the neurovascular femoral bundle (including the superficial femoral artery [SFA], femoral vein [FV], and femoral nerve) was accidently transected with subsequent development of ALLI. Therefore, the FV was harvested distally to the injury site and a 4-cm long healthy segment was obtained. It was reversed, flushed with heparin, spatulated at both extremities, and interposed to the SFA in end-to-end fashion using two 9/0 polypropylene interrupted sutures under microscope. Reperfusion of the limb was noted immediately after releasing the vascular clamps. The final ischemia time at completion of the surgical procedure was 6 hr. Thereby, prophylactic 4-compartment fasciotomies were performed in the right leg. The patient tolerated the procedure well and the postoperative clinical course was free from adverse events. Duplex ultrasound examination at 6 weeks after the intervention confirmed sustained clinical success and showed no signs of venous thromboembolism. At the same time, X-ray examination of the right hip confirmed adequate and stable reduction of the joint in the acetabulum. ALLI due to accidental arterial injury during orthopedic surgical procedures for congenital defects in newborns is a rare but potentially devastating complication. Microsurgical salvage is a safe, feasible, and effective option to restore limb flow. Multidisciplinary expertise and meticulous technique are mandatory in order to achieve satisfactory and durable outcomes.