Multivisceral transplantation for diffuse splanchnic venous thrombosis:

Innovative surgical techniques in the intestine and multivisceral transplant

PURPOSE OF REVIEW

This timely review delves into the evolution of multivisceral transplantation (MVT) over the past six decades underscoring how advancements in surgical techniques and immunosuppression have driven transformation, to provide insight into the historical development of MVT, shedding light on its journey from experimentation to a valuable clinical approach.

RECENT FINDINGS

The review presents contemporary enhancements in surgical methods within the context of intestinal transplantation. The versatility of MVT is emphasized, accommodating diverse organ combinations and techniques. Both isolated intestinal transplantation (IIT) and MVT have seen expanded indications, driven by improved parenteral nutrition, transplantation outcomes, and surgical innovations. Surgical techniques are tailored based on graft type, with various approaches for isolated transplantation. Preservation strategies and ostomy techniques are also covered, along with graft assessment advancements involving donor-specific antibodies.

SUMMARY

This review's findings underscore the remarkable evolution of MVT from experimental origins to a comprehensive clinical practice. The progress in surgical techniques and immunosuppression has broadened the spectrum of patients who can benefit from intestinal transplant, including both IIT and MVT. The expansion of indications offers hope to patients with complex gastrointestinal disorders. The detection of donor-specific antibodies in graft assessment advances diagnostic accuracy, ultimately improving patient outcomes.

Small bowel transplant - novel indications and recent progress

INTRODUCTION

Advances in the management of intestinal failure have led to a reduction in the number of intestinal transplants. The number of bowel transplants has been mainly stable even though a slight increase has been observed in the last 5 years.

AREAS COVERED

Standard indication includes patients with a reasonable life expectancy. Recent progress can be deduced by the increased number of intestine transplants in adults: this is due to the continuous improvement of 1-year graft survival worldwide (without differences in 3- and 5-year) associated with better abdominal wall closure techniques. This review aims to provide an update on new indications and changes in trends of pediatric and adult intestine transplantation. This analysis, which stretches through the past 5 years, is based on a collection of related manuscripts from PubMed.

EXPERT COMMENTARY

Intestinal transplants should be solely intended for a group of individuals for whom indications for transplantation are clear and both medical and surgical rehabilitations have failed. Nevertheless, many protocols developed over the years have not yet solved the key question represented by the over-immunosuppression. Novel indications and recent progress in the bowel transplant field, minimal yet consistent, represent a pathway to be followed.

Portal Interventions in the Setting of Venous Thrombosis or Occlusion

Portal vein thrombosis most commonly occurs as a complication of liver cirrhosis and can result in worsening symptoms of portal hypertension, which often can be challenging to treat with conventional decompression therapies. In addition, because complete portal vein thrombosis is associated with higher posttransplant morbidity and mortality, it is regarded as a relative contraindication to liver transplant. Often, the diagnosis of portal vein thrombosis is incidental; hence, imaging remains the mainstay for diagnosing this complication and is used to guide subsequent treatment. Although anticoagulation is the initial approach used to treat acute portal vein thrombosis, endovascular and/or surgical interventions may be necessary when there is concern for impending bowel ischemia. Treatment of chronic portal vein thrombosis is primarily aimed at alleviating the symptoms of portal hypertension and improving the chance of candidacy for liver transplant. Awareness of the portal venous anatomy to differentiate it from the periportal collaterals is key during recanalization of a chronically occluded portal vein. The authors provide an overview of the pathophysiology, acute and chronic imaging findings, and management of portal vein thrombosis, with a specific focus on endovascular management, as well as a summary of the current related literature. An invited commentary by Lopera and Yamaguchi is available online. ©RSNA, 2022.

Trombose de veia porta não associada à cirrose – desafio terapêutico

Portal vein thrombosis (PVT) is a disease in which thrombosis occurs from the intrahepatic branches of the portal vein, and may extend to the splenic vein and/or superior mesenteric vein. It is most often associated with liver cirrhosis. PVT not associated with cirrhosis is rare. The aim of this article is to report two cases of PVT in which it was not associated with cirrhosis. Both were treated with anticoagulation and clinical progress afterwards was good.

Management of portal vein thrombosis in cirrhotic patients enlisted for liver transplantation: From diagnosis to treatment (Review)

Portal vein thrombosis (PVT) commonly occurs in patients with cirrhosis. Several classification systems of PVT have been proposed over the years reflecting the challenge in establishing a widely accepted system. To date, PVT has been considered an absolute contraindication for orthotopic liver transplantation (OLT) since it is associated with decreased graft survival and increased patient mortality. Nevertheless, the development of modern surgical techniques has enabled the inclusion of these candidates in OLT waiting lists, since their postoperative results are shown to be comparable to those of patients without PVT. The aim of the present review was to critically appraise the available treatment options for cirrhotic patients enlisted for liver transplantation in the setting of PVT.

Multivisceral Transplantation for Diffuse Portomesenteric Thrombosis: Lessons Learned for Surgical Optimization

Background: Multivisceral transplantation entails the en-bloc transplantation of stomach, duodenum, pancreas, liver and bowel following resection of the native organs. Diffuse portomesenteric thrombosis, defined as the complete occlusion of the portal system, can lead to life-threatening gastrointestinal bleeding, malnutrition and can be associated with liver and intestinal failure. Multivisceral transplantation is the only procedure that offers a definitive solution by completely replacing the portal system. However, this procedure is technically challenging in this setting. The aim of this study is to describe our experience, highlight the challenges and propose technical solutions.

Materials and Methods: We performed a retrospective analysis of our cohort undergoing multivisceral transplantation for diffuse portomesenteric thrombosis at our institution from 2000 to 2020. Donor and recipient demographics and surgical strategies were reviewed in detail and posttransplant complications and survival were analyzed.

Results: Five patients underwent MVTx. Median age was 47 years (23–62). All had diffuse portomesenteric thrombosis with life-threatening variceal bleeding. Major blood loss during exenteration was avoided by combining two techniques: embolization of the native organs followed by a novel, staged extraction. This prevented major perioperative blood loss [median intra-operative transfusion of 3 packed red blood cell units (0–5)]. Median CIT was 330 min (316–416). There was no perioperative death. One patient died due to invasive aspergillosis. Four others are alive and well with a median follow-up of 4.1 years (0.3–5.9).

Conclusions: Multivisceral transplantation should be considered in patients with diffuse portomesenteric thrombosis that cannot be treated by any other means. We propose a standardized surgical approach to limit the operative risk and improve the outcome.

Multivisceral transplant as an option to transplant cirrhotic patients with severe portal vein thrombosis

Non-tumoral portal vein thrombosis (PVT) is a critical complication in the patient with advanced cirrhosis awaiting liver transplantation (LT). With the evolution of liver transplant (LT) technique, PVT has morphed from an absolute contraindication to a relative contraindication, depending on the grade of the thrombus. The Yerdel classification is one system of grading PVT severity. Patients with Yerdel class 1-3 PVT can undergo LT at centers with experience in complex portal vein (PV) dissection, thrombectomy, and reconstruction. Class 4 PVT, however, is even more complex and may require heroic techniques such as cavoportal hemitransposition, PV arterialization or multivisceral transplant (MVT). Some centers use a MVT back-up approach for patients with Yerdel class 4 PVT. In these patients, all organs with PV outflow are procured simultaneously as a cluster graft from a deceased donor (liver, pancreas, intestine±stomach). If physiologic PV inflow is established intraoperatively, the recipient undergoes LT. Otherwise the MVT graft is transplanted. MVT establishes physiologic PV flow, but transplantation of the intestine confers significant lifelong risks including rejection, graft-versus host disease and post-transplant lymphoma. Yerdel class 1-4 PVT patients undergoing successful LT have 5-year survival similar to non-PVT patients, while patients requiring full MVT experience somewhat higher mortality because of the complexity of the surgery and medical management.

Cavoportal Hemitransposition in Liver Transplantation: Toward a More Safe and Efficient Technique

Extended splanchnic venous thrombosis represents a challenge for the liver transplantation (LT) surgeon. In the absence of large venous tributaries, the cavoportal hemitransposition (CPHTr) and the combined liver-intestinal or multivisceral transplantation are the only technical solutions. Because of the reported high morbidity and mortality rates due to infrequent use and a lack of standardization, the former technique has been almost abandoned by the transplant community. A newly designed technique of CPHTr is presented that is based on the combination of an inferior vena cava (IVC)-sparing hepatectomy and large laterolateral cavocaval and end-to-side cavoportal anastomoses separated only by a double vascular stapler line. This technique allows the splanchnic blood to be completely diverted toward the allograft and to eliminate low-flow IVC areas, which possibly lead to complications. The modified CPHTr technique proposed here offers a valuable alternative to much more complex and invasive intestinal transplantation procedures.

Visceral arterial embolization prior to multivisceral transplantation in recipient with cirrhosis, extensive portomesenteric thrombosis, and hostile abdomen: Performance and outcome analysis

Multivisceral transplant (MVT) for cirrhosis, and portomesenteric vein thrombosis (PVT), is fraught with life-threatening thrombo-hemorrhagic complications. Embolization of native viscera has been attempted in a handful of cases with mixed results. We carried out a comparative analysis of angiographic, intra-operative, and pathological findings in three recipients of MVT who were deemed exceptionally high hemorrhagic risk and therefore underwent preoperative visceral embolization. All recipients were male with cirrhosis, PVT, and a surgical history indicative of diffuse visceral adhesions; status post-liver transplantation (n = 2) and proctocolectomy (n = 1). The first patient had two Amplatzer II embolization plugs placed 2 cm from the origins of celiac and superior mesenteric (SMA) arteries. Distal migration of the celiac plug into gastroduodenal artery (GDA) and ensuing ischemia reperfusion injury, presumably contributed to severe disseminated intravascular coagulation (DIC) and intra-operative mortality. In the other two recipients, distal Gelfoam embolization of the SMA, GDA, and splenic arteries was performed, and although remarkable hemorrhage and coagulopathy occurred, embolization, undoubtedly, facilitated exenteration and improved outcomes. Pathologic examination in these cases confirmed ischemic necrosis of eviscerated bowel. In conclusion, liver-sparing, preoperative distal embolization of native viscera with Gelfoam is beneficial, but entails several pitfalls. It should currently be reserved for MVT recipients who otherwise are at unacceptably high risk.

Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis

Portal vein thrombosis unrelated to solid malignancy is common in patients with cirrhosis, but less frequently observed in patients without cirrhosis. Prompt diagnosis and management of acute symptomatic portal vein thrombosis are essential. Failure to detect and treat thromboses can result in mesenteric ischemia, chronic cavernous transformation, and complications of portal hypertension. In patients with cirrhosis, development of portal vein thrombosis is often insidious and remains undetected until its incidental detection. Management of portal vein thrombosis in patients with cirrhosis is more controversial. However, there are data to support treatment of specific patients with anticoagulation agents. We review the common and distinct features of portal vein thromboses in patients without liver tumors, with and without cirrhosis.

Anesthesia for Intestinal Transplantation

The diagnosis of irreversible intestinal failure confers significant morbidity, mortality, and decreased quality of life. Patients with irreversible intestinal failure may be treated with intestinal transplantation. Intestinal transplantation may include intestine only, liver-intestine, or other visceral elements. Intestinal transplantation candidates present with systemic manifestations of intestinal failure requiring multidisciplinary evaluation at an intestinal transplantation center. Central access may be difficult in intestinal transplantation candidates. Intestinal transplantation is a complex operation with potential for hemodynamic and metabolic instability. Patient and graft survival are improving, but graft failure remains the most common postoperative complication.