Twenty years of follow-up of aortohepatic conduits in 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.

Splenic Artery Transposition for Liver Transplantation: An Underutilized Technique?

BACKGROUND

Successful liver transplantation is dependent on restoration of hepatic arterial (HA) flow. Although uncommon, some native recipient HAs are not suitable or inadequate for anastomosis, thereby necessitating extra-anatomic HA reconstruction. Splenic artery transposition (SAT) is 1 method of HA reconstruction, in which the recipient splenic artery is transposed to reestablish perfusion of the donor liver. Due to the rarity of the technique, literature describing outcomes is limited. In the current report, we describe 3 patients (2 adults, 1 pediatric) who underwent complex upper abdominal surgery before whole-organ deceased donor liver transplantation with SAT.

METHODS

The demographic and patient care information was collected prospectively and subsequently reviewed retrospectively. Given the de-identified nature of the data included, this study was exempt from approval from an ethics board.

RESULTS

Recipient splenic arteries were dissected from their origin at the celiac trunk, for approximately 3-5 cm to ensure a gentle anterior-cranial curve toward the right upper quadrant, allowing anastomosis to the donor celiac trunk in an end-to-end fashion. Postoperatively, all 3 patients had rapid normalization of liver function tests and brisk HA flow demonstrated by Doppler ultrasound. Longer-term follow-up, ranging from 1 to 3 years, reveals continued patency of the reconstructed HAs and liver function tests within normal limits.

CONCLUSIONS

Our experience points to SAT as a safe and effective technique for extra-anatomic HA reconstruction.

Comparison of Supraceliac and Infrarenal Aortic Conduits in Liver Transplantation: Is There a Difference in Patency and Postoperative Renal Dysfunction?

Aorto-hepatic conduits can provide arterial inflow for liver transplants in cases where the native hepatic artery is unsuitable for use.

A systematic review and meta-analysis of rescue revascularization with arterial conduits in liver transplantation

Although aortohepatic conduits (AHCs) provide an effective technique for arterialization in liver transplantation (LT) when the native recipient artery is unusable, various publications report higher occlusion rates and impaired outcome compared to conventional anastomoses. This systematic review and meta-analysis investigates the published evidence of outcome and risk of AHCs in LT using bibliographic databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Primary and secondary outcome were artery occlusion as well as graft and patient survival. Twenty-three retrospective studies were identified with a total of 22 113 patients with LT, of whom 1900 patients (9%) received an AHC. An AHC was used in 33% of retransplantations. Early artery occlusion occurred in 7% (3%-16%) of patients with AHCs, compared to 2% (1%-3%) without conduit (OR 3.70; 1.63-8.38; P = .001). The retransplantation rate after occlusion was not significantly different in both groups (OR 1.46; 0.67-3.18; P = .35). Graft (HR 1.38; 1.17-1.63; P < .001) and patient (HR 1.57; 1.12-2.20; P = .009) survival was significantly lower in the AHC compared to the nonconduit group. In contrast, graft survival in retransplantations was comparable (HR 1.00; 0.82-1.22; P = .986). Although AHCs provide an important rescue option, when regular revascularization is not feasible during LT, transplant surgeons should be alert of the potential risk of inferior outcome.

Hepatic artery occlusion in liver transplantation: What counts more, the type of reconstruction or the severity of the recipient's disease?

Although the type of hepatic artery revascularization technique is known to have an impact on patency rates, independent perioperative risk factors on patient outcomes are poorly defined. All consecutive adult patients undergoing cadaveric liver transplantation (n = 361) from July 2007 to June 2016 in a single institution were analyzed. Primary outcomes were early (<30 days) hepatic artery occlusion and primary hepatic artery patency rate. A multivariate model was used to identify independent risk factors for occlusion and the need of arterial conduit, as well as their impact on graft and patient survival. Arterial revascularization without additional reconstruction (end-to-end arterial anastomosis [AA]) was performed in 77% (n = 279), arterial reconstruction (AR) in 15% (n = 53), and aortohepatic conduit (AHC) in 8% (n = 29) of patients. AHC had the highest mean intraoperative flow (275 mL/minute; P = 0.02) compared with AA (250 mL/minute) and AR (200 mL/minute; P = 0.02). There were 43 recipients (12%) who had an occlusive event with successful revascularization in 20 (47%) recipients. One-year primary patency rates of AA, AR, and AHC were 97%, 88%, and 74%, respectively. Aortic calcification had an impact on early occlusion. AR (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.26-10.75; P = 0.02) and AHC (OR, 6.21; 95% CI, 2.02-18.87; P = 0.001) were independent risk factors for early occlusion. Dyslipidemia additionally independently contributed to early occlusion (OR, 2.74; 95% CI, 0.96-7.87; P = 0.06). The 1- and 5-year graft survival rates were 83% and 70% for AA, 75% and 69% for AR, and 59% and 50% for AHC (P = 0.004), respectively. In conclusion, arterial patency is primarily determined by the type of vascular reconstruction rather than patient or disease characteristics. The preoperative lipid status is an independent risk factor for early occlusion, whereas overall occlusion is only based on the performed vascular reconstruction, which is also associated with reduced graft and patient survival. Liver Transplantation 24 790-802 2018 AASLD.

Pediatric Liver Transplant: Techniques and Complications

Liver transplant is considered to be the last-resort treatment approach for pediatric patients with end-stage liver disease. Despite the remarkable advance in survival rates, liver transplant remains an intricate surgery with significant morbidity and mortality. Early diagnosis of complications is crucial for patient survival but is challenging given the lack of specificity in clinical presentation. Knowledge of the liver and vascular anatomy of the donor and the recipient or recipients before surgery is also important to avoid complications. In this framework, radiologists play a pivotal role on the multidisciplinary team in both pre- and postoperative scenarios by providing a road map to guide the surgery and by assisting in diagnosis of complications. The most common complications after liver transplant are (a) vascular, including the hepatic artery, portal vein, hepatic veins, and inferior vena cava; (b) biliary; (c) parenchymal; (d) perihepatic; and (e) neoplastic. The authors review surgical techniques, the role of each imaging modality, normal posttransplant imaging features, types of complications after liver transplant, and information required in the radiology report that is critical to patient care. They present an algorithm for an imaging approach for pediatric patients after liver transplant and describe key points that should be included in radiologic reports in the pre- and postoperative settings. Online supplemental material is available for this article. ^©RSNA, 2017.

Placement of an Aortohepatic Conduit as an Alternative to Standard Arterial Anastomosis in Liver Transplantation

Background

The aim of this study was to assess the impact of placement of an aortohepatic conduit on graft and patient survival after liver transplantation (LT) in selected patients with an inadequate recipient hepatic artery (HA) for a standard arterial anastomosis.

Material/Methods

Of 331 patients who underwent deceased donor LT, 25 (7.6%) who received placement of an aortohepatic conduit at the time of transplantation were included. Clinical characteristics and outcomes, including postoperative complications, conduit patency, and graft and patient survival rates, were analyzed.

Results

All 25 patients included in this study presented a high preoperative Model for End-stage Liver Disease score (25.4±8.6; range, 6–42) and high rates of retransplantation (n=11, 44%) or previous abdominal – pelvic surgery (n=5, 20%). The observed postoperative vascular complications were portal vein thrombosis in 3 cases (12%) and anastomosis-site bleeding of the aortohepatic conduit in 1 case (4%); there was no HA thrombosis or stenosis in our analysis. With a median follow-up of 37 months (range, 0–69 months), all aortohepatic conduits were patent, and the graft and patient survival rates were 84% and 68%, respectively. The causes of death were graft failure (n=4), pneumonia (n=3), and cerebrovascular accidents (n=1).

Conclusions

Our results indicate that placement of an aortohepatic conduit is a feasible alternative to a standard arterial anastomosis in selected patients whose HA and surrounding potential inflow arteries are not suitable for standard arterial anastomosis.

A New Consideration in Hepatic Artery Reconstruction in Adult Liver Transplant: Arterial Transposition Versus Extra-Anatomic Jump Grafts

OBJECTIVES

In some cases of liver transplant, standard hepatic artery reconstruction may be difficult or impossible due to inadequate flow of the recipient's hepatic artery, as a result of stenosis, intimal dissection, or anomalies of the hepatic artery. We compared splenic artery transposition with extra-anatomic jump graft as 2 alternative methods for hepatic artery reconstruction in these situations.

MATERIALS AND METHODS

We reviewed the files of 2135 liver transplant recipients from March 2011 to February 2016 at the Shiraz Transplant Center. Data of 93 patients with unusual hepatic artery reconstruction were analyzed to assess outcomes, morbidity, mortality, and pre- and posttransplant parameters (both clinical and paraclinical). Patients were divided into 2 groups: 17 with splenic artery transposition (splenic artery group) and 76 with extra-anatomic jump grafts (control group).

RESULTS

There was only 1 occurrence (5.8%) of hepatic artery thrombosis in the splenic artery group causing extra-anatomic jump graft. However, in the control group, there were 4 occurrences (5.2%) of hepatic artery thrombosis, causing 1 revision of anastomosis and 3 retransplant procedures. No deaths due to hepatic artery complications were reported in the 2 groups. Three-year survival rate was 87.5% in the splenic artery group and 68.9% in the control group.

CONCLUSIONS

Splenic artery transposition is an acceptable method for hepatic artery reconstruction in deceased-donor liver transplant procedures with no greater rates of complication or morbidity than extra-anatomic jump grafts. Less operation time and better exposure during surgery are advantages of this method.

Liver Transplantation Utilizing Mixed Biologic and Synthetic Arterial Conduits

Arterial conduits are necessary in nearly 5% of all liver transplants and are usually constructed utilizing segments of donor iliac artery. However, available segments of donor iliac artery may not be lengthy enough or may not possess enough quality to enable its inclusion in the conduit. Although there are few reports of arterial conduits constructed solely utilizing prosthetic material, no previous reports of conduits composed of a segment of donor iliac artery and prosthetic material (mixed biologic and synthetic arterial conduits) were found in the medial literature to date. Two cases reporting successful outcomes after creation of mixed biologic and prosthetic arterial conduits are outlined in this report. Reason for creation of conduits was complete intimal dissection of the recipient's hepatic artery in both cases. In both cases, available segments of donor iliac artery were not lengthy enough to bridge infrarenal aorta to porta hepatis. Both patients have patent conduits and normally functioning liver allografts, respectively, at 4 and 31 months after transplant. Mixed biologic and synthetic arterial conduits constitute a viable technical option and may offer potential advantages over fully prosthetic arterial conduits.

The role of arterial conduits for revascularisation in adult orthotopic liver transplantation

The successful outcome in orthotopic liver transplantation (OLT) is critically dependent on the uncompromised hepatic graft blood inflow. Arterial conduits represent a good solution in cases where conventional revascularisation is not possible. The purpose of this systematic review is to analyse the published evidence on the use of arterial conduits in adult OLT. After review of the Pubmed and EMBASE databases, 19 relevant studies were identified and analysed. Even though patient survival was comparable, most large studies reported worse 1-, 3- and 5-year graft survival rates compared to grafts with standard arterial revascularisation. Primary grafts were more commonly affected than re-grafts. Early and late hepatic artery thrombosis occurred more commonly, while the use of an arterial conduit was identified as an independent risk factor. The overall biliary complications were comparable, however, ischaemic cholangiopathy was encountered about 3 times more in patients with arterial conduits and strongly correlated with the occurrence of late HAT. In conclusion, the use of arterial conduit is a useful option in adult OLT in cases that the conventional revascularisation technique cannot be used or results in suboptimal arterial inflow. More studies directly addressing issues such as pre-operative evaluation regarding the need for arterial conduit, the types of vessels used, positioning of the conduit and post-operative management are required.

The recipient celiac trunk as an alternative to the native hepatic artery for arterial reconstruction in adult liver transplantation

During liver transplantation (LT), the recipient hepatic artery (RHA) cannot always be used, and alternatives include aortohepatic conduits and the splenic artery (SA). We report our experience with arterial reconstruction on the recipient celiac trunk (RCT), which has rarely been described. Since January 2013, we have been using the RCT when the RHA could not be used. All cases were discussed in a multidisciplinary LT meeting, and arterial patency or anomalies were systemically viewed with computed tomography (CT) scan. The RCT was used after section-ligation of all celiac trunk collaterals. Until May 2014, the RHA could not be used in 11/139 (8%) patients who underwent LT. Postoperative arterial patency was assessed by serial Doppler ultrasound and CT scan. The advantages and disadvantages of the different arterial conduits were evaluated. The RCT was used in 7/11 (64%) patients. Mean follow-up was 10 (6-15) months. The patency rate was 100%, and 1 patient with associated portal shunting died at day 20 from septic complications. No related gastric or splenic complications were encountered. The RCT could not be used in 4 patients with reconstruction on the SA (n = 2), infrarenal (n = 1), and supraceliac aorta (n = 1). The patency rate was 75%. One patient with SA conduit and portal shunting developed pancreatitis/anastomotic pseudoaneurysm with secondary rupture. An emergency infrarenal conduit was created, which was later embolized because of infected pseudoaneurysms. Although the literature reports a higher risk of thrombosis with aortohepatic conduits, no long-term results are available for the SA conduits, and only 1 report is available for the RCT. In conclusion, this study shows that the RCT is a good alternative to the RHA and can be used in two-thirds of patients with inadequate RHA flow.

Concurrent hepatic artery and portal vein thrombosis after orthotopic liver transplantation with preserved allografts

In contrast to early HAT, late HAT has an insidious clinical presentation. Nevertheless, biliary and vascular reconstructions in this late setting are unlikely to improve outcome. Patent portal flow makes an important contribution to the viability of liver in case of late HAT while the allograft reconstitutes intrahepatic arterial flow through neovascularization. Concurrent HAT with PVT without immediate graft necrosis is extremely rare, and allograft and patient survival are seemingly impossible without retransplantation. In fact, hepatopetal arterial and portal venous neovascularization are known albeit obscure phenomena that can preserve posttransplant hepatic function under the extenuating circumstances of complete interruption of blood flow to the graft. We describe two such cases that developed combined HAT and PVT more than six months after OLT with perfect preservation of graft function. The survival of allografts in our cases was due to extensive hepatopetal arterial and portal venous collateralization. Simultaneous HAT and PVT after OLT are rare events and almost uniformly fatal, if they occur early. Due to paucity of such cases, however, underlying mechanisms and etiology remain elusive, and despite radiological diagnosis of these complications, there is no way to predict these events in the wake of stable graft function.

Use of the recipient celiac trunk for hepatic artery reconstruction in orthotopic liver transplantation

Arterial complications contribute to significant morbidity and mortality after liver transplantation (OLT). If hepatic artery inflow to the graft is inadequate, alternative approaches can be considered, such as supraceliac or infrarenal aortic conduits and splenic artery as an arterial inflow. Between January 2005 and January 2012, we performed 928 OLTs. We used the recipient celiac trunk for arterial inflow in 9 patients (1%). evaluated retrospectively, We the indications, results, and outcome of this technique. Doppler ultrasound of the liver was used to evaluate arterial flow. Eight cases are first transplant and 1 case is a second transplant. Five cases are pediatric recipients and four cases are adult recipients. Male to female ratio is 3/6. Average follow-up is 23 months. No complications were encountered as a result of sacrificing the branches of the celiac axis. The conclusion is that the celiac trunk provides an adequate arterial inflow in OLT when the recipient's hepatic artery is not suitable to use.

Long-term deleterious effects of aortohepatic conduits in primary liver transplantation: proceed with caution

Aortohepatic conduits provide a vital alternative for graft arterialization during liver transplantation. Conflicting results exist with respect to the rates of comorbidities, and long-term survival data on primary grafts are lacking. To identify the complications associated with aortohepatic conduits in primary liver transplantation and their impact on survival, we conducted a single-center, retrospective cohort analysis of all consecutive adult (n = 1379) and pediatric primary liver transplants (n = 188) from 1998 to 2009. The outcomes of aortohepatic conduits were compared to those of standard arterial revascularization. Adults with a conduit (n = 267) demonstrated, in comparison with adults with standard arterialization (n = 1112), an increased incidence of late (>1 month after transplantation) hepatic artery thrombosis (HAT; 4.1% versus 0.7%, P < 0.001) and ischemic cholangiopathy (7.5% versus 2.7%, P < 0.001) and a lower 5-year graft survival rate (61% versus 70%, P = 0.01). The adjusted hazard ratio (HR) for graft loss in the conduit group was 1.38 [95% confidence interval (CI) = 1.03-1.85, P = 0.03]. Notably, the use of conduits (HR = 4.91, 95% CI = 1.92-12.58) and a warm ischemia time > 60 minutes (HR = 11.12, 95% CI = 3.06-40.45) were independent risk factors for late HAT. Among children, the complication profiles were similar for the conduit group (n = 81) and the standard group (n = 107). In the pediatric cohort, although the 5-year graft survival rate for the conduit group (69%) was significantly impaired in comparison with the rate for the standard group (81%, P = 0.03), the use of aortohepatic conduits did not emerge as an independent predictor of diminished graft survival via a multivariate analysis. In conclusion, in adult primary liver transplantation, the placement of an aortohepatic conduit should be strictly limited because of the greater complication rates (notably late HAT) and impaired graft survival; for children, its judicious use may be acceptable.

Complex vascular reconstruction using donor's vessel grafts in orthotopic liver transplantation

The vascular abnormalities of recipients are associated with reconstructive difficulties with an increased risk of postoperative complications. We performed an orthotopic liver transplantation that required a complex vascular reconstruction using donor vascular grafts. A patient with hepatitis B virus cirrhosis received a liver from a brain-dead donor. Dynamic computed tomography revealed complete obstruction of the portal vein due to thrombosis as well as narrowing of the hepatic arteries. We employed orthotopic liver transplantation using the piggy-back technique with complex reconstruction of the portal vein and the hepatic arteries. For portal vein reconstruction, we used the donor's iliac vein as an interpositional conduit from the recipient's gastric coronary vein to graft the portal vein. The hepatic arteries of the graft were reconstructed at the back-table before anastomosis to the side of superior mesenteric artery using an interpositional conduit of the donor's external iliac artery. All postoperative studies revealed good graft function with an excellent blood flow through all vascular anastomoses during the first year postoperatively.

Vascular complications of orthotopic liver transplantation: experience in more than 4,200 patients

BACKGROUND

Thromboses of the hepatic artery (HAT) and portal vein (PVT) may complicate orthotopic liver transplantation (OLT) and result in graft loss and mortality. Revision and retransplantation are treatment options, but their longterm outcomes remain undefined. This study was undertaken to evaluate the incidence of major vascular complications after OLT, determine efficacy of therapies, and identify factors influencing longterm outcomes.

STUDY DESIGN

All patients undergoing OLT from 1984 to 2007 were evaluated. Kaplan-Meier analysis was performed to define the effects of vascular complications on posttransplant survival. Anastomotic revision and arterial thrombolysis were compared with retransplantation as treatment for HAT. After 2002, porta hepatis dissection was initiated with early occlusion of common hepatic artery (CHA) inflow; its impact on HAT incidence was determined.

RESULTS

From 1984 to 2007, 4,234 OLTs were performed. HAT occurred in 203 patients (5%) and PVT in 84 (2%). Graft survival was significantly reduced by HAT or PVT; patient survival was reduced only by PVT. Retransplantation for HAT improved patient survival over revision or thrombolysis in the first year but did not provide longterm survival advantage (56% versus 56% at 5 years; p=0.53). Patients with HAT had only 10% graft salvage with anastomotic revision or thrombolysis. HAT was significantly reduced with early CHA inflow occlusion (1.1% versus 3.7%; p=0.002). Factors increasing risk of HAT included pediatric recipients, liver cancer, and aberrant arterial anatomy requiring complex reconstruction.

CONCLUSIONS

Both HAT and PVT significantly reduce graft survival after OLT; PVT more adversely affects patient survival. Revision and thrombolysis rarely salvage grafts after HAT; retransplantation provides superior short-term, but not longterm, survival. Avoidance of vascular complications in OLT is critical, especially with today's scarcity of donor livers. Early atraumatic CHA occlusion significantly reduces the incidence of HAT.