Management of Major Portosystemic Shunting in Small-for-Size Adult Living-Related Donor Liver Transplantation with a Left-Sided Graft Liver

Makeshift Shunts in Extrahepatic Portal Vein Obstruction in Pediatric Population

Background and Objectives

More than 20% of patients with extrahepatic portal vein obstruction (EHPVO) may be deemed as nonshuntable due to lack of a suitable vein. The role of "makeshift shunts" or "lesser shunts" assumes importance in such cases. In this report, the authors have shared their experience with the makeshift shunts in the management of portal hypertension in children with emphasis upon anatomic considerations, resolution of symptoms, outcomes after surgery, and shunt patency.

Materials and Methods

During the period 1983-2018, 138 children with portal hypertension were managed under the care of a single surgeon (VB). Of them, 134 were EHPVO. Children with EHPVO were treated with splenectomy and proximal lienorenal shunt (n = 107), splenectomy and devascularization (n = 21), and makeshift shunts (n = 6). Makeshift shunts comprised (i) side-to-side right gastroepiploic vein (Rt-GEV) to left renal vein (LRV) shunt (n = 1), (ii) superior mesenteric vein (SMV) to inferior vena cava (IVC) shunt using a spiral saphenous venous graft (n = 1), (iii) side-to-side inferior mesenteric vein (IMV) to LRV shunt (n = 2), (iv) side-to-side IMV to IVC shunt (n = 1), (v) end-to-side IMV to IVC shunt (n = 1), and (vi) side-to-side IMV to LRV shunt (n = 1) in a case of crossed fused renal ectopia.

Results

Following the creation of portosystemic shunt, a decline in portal pressure was demonstrated in all six patients. There was resolution of symptoms including hematemesis, melena, and anorectal variceal bleed. None of the patients demonstrated the features of hepatic encephalopathy. The associated portal cavernoma cholangiopathy (n = 1) also resolved following Rt-GEV to LRV shunt. Shunt patency was documented for the entire duration of follow-up (1.5-4 years) in five of six patients; the sixth patient demonstrated shunt block at 6-month follow-up but without recurrence of symptoms.

Conclusions

Makeshift shunts offer a viable alternative to standard portosystemic shunting in pediatric patients with a nonshuntable vein. The selection of such shunts is, however, subject to surgeon's preferences and has to be individualized to local anatomy.

Clinical Significance of Spontaneous Portosystemic Shunts in Living Donor Liver Transplantation

Spontaneous portosystemic shunts (SPSS) are commonly observed in patients undergoing living donor liver transplantation (LDLT); however, their impact on the outcome after transplantation is unclear. We aimed to assess the type, size, and the effects of SPSS on outcomes after LDLT. A total of 339 LDLT recipients in a single institution were included. The type and diameter of the SPSS (splenorenal shunt [SRS], oesogastric shunt, and umbilical shunt) were retrospectively analyzed. A large shunt was defined as having a diameter ≤7 mm. No portal flow modulation was attempted over time. Portal complications were defined as stenosis, thrombosis, or hepatofugal flow requiring any treatment after transplantation. There were 202 (59.0%) patients who exhibited at least 1 large SPSS. Neither the size nor type of SPSS was associated with mortality, morbidity, or liver function recovery. However, the incidence of portal complications was significantly higher in patients with a large SRS (8.6% versus 2.9%; P = 0.04). Multivariate analysis of portal complications revealed 2 independent predictors: pre-LT portal vein thrombosis (PVT) and SRS size. The observed risk among recipients with pre-LT PVT was 8.3% when the SRS was ≤7 mm, but increased to 38.5% when the SRS was >15 mm. The present study suggests that large SPSS do not negatively affect the outcomes after LDLT. However, a large SRS is associated with a higher risk of portal complications, particularly in recipients with pre-LT PVT, for whom intraoperative intervention for SRS should be considered. Otherwise, a conservative approach to SPSS during LDLT seems reasonable.

Small-for-size syndrome in liver transplantation: Definition, pathophysiology and management

BACKGROUND

Since the first success in an adult patient, living donor liver transplantation (LDLT) has become an universally used procedure. Small-for-size syndrome (SFSS) is a well-known complication after partial LT, especially in cases of adult-to-adult LDLT. The definition of SFSS slightly varies among transplant physicians. The use of a partial liver graft has risks of SFSS development. Persistent portal vein (PV) hypertension and PV hyper-perfusion after LT were identified as the main factors. Hence, various approaches were explored to modulate PV flow and decrease PV pressure in order to alleviate this syndrome. Herein, the definition, clinical symptoms, pathophysiology, basic research, as well as preventive and treatment strategies for SFSS are reviewed based on an extensive review of the literature and on our own experiences.

DATA SOURCES

The articles were collected through PubMed using search terms "liver transplantation", "living donor liver transplantation", "living liver donation", "partial graft", "small-for-size graft", "small-for-size syndrome", "graft volume", "remnant liver", "standard liver volume", "graft to recipient body weight ratio", "sarcopenia", "porcine", "swine", and "rat". English publications published before March 31, 2020 were included in this review.

RESULTS

Many transplant surgeons performed PV flow modulation, including portocaval shunt, splenic artery ligation and splenectomy. With these techniques, patient outcome has been improved even when using a "small" graft. Other factors, such as preoperative recipients' nutritional and skeletal muscle status, graft congestion, and donor factors, were also identified as risk factors which all have been addressed using various strategies.

CONCLUSIONS

The surgical approach controlling PV flow and pressure could help to prevent SFSS especially in severely ill recipients. In the absence of efficacious medications to resolve SFSS, conservative treatments, including aggressive fluid balance correction for massive ascites, anti-microbiological therapy to prevent or control sepsis and intensive nutritional therapy, are all required if SFSS could not be prevented.

Unusual spontaneous porto-systemic shunt: The importance of diagnosing non-anatomical porto-systemic shunts to improve portal flow in pediatric living-related liver transplantation. Case report

Collateral circulation secondary to liver cirrhosis may cause the development of large PSSs that may steal flow from the main portal circulation. It is important to identify these shunts prior to, or during the transplant surgery because they might cause an insufficient portal flow to the implanted graft. There are few reports of "steal flow syndrome" cases in pediatrics, even in biliary atresia patients that may have portal hypoplasia as an associated malformation. We present a 12-month-old female who received an uneventful LDLT from her mother, and the GRWR was 4.8. During the early post-operative period, she became hemodynamically unstable, developed ascites, and altered LFT. The post-operative ultrasound identified reversed portal flow, finding a non-anatomical PSS. A 3D CT scan confirmed the presence of a mesocaval shunt through the territory of the right gonadal vein, draining into the right iliac vein, with no portal inflow into the liver. The patient was re-operated, and the shunt was ligated. An intraoperative Doppler ultrasound showed adequate portal inflow after the procedure; the patient evolved satisfactorily and was discharged home on day number 49. The aim was to report a case of post-operative steal syndrome in a pediatric recipient due to a mesocaval shunt not diagnosed during the pretransplant evaluation.

Tips and pitfalls in direct ligation of large spontaneous splenorenal shunt during liver transplantation

Patients with large spontaneous splenorenal shunts (SRSs) prove challenging during liver transplantation (LT), regardless of organizing portal vein (PV) thrombosis. Here, we detail the clinical outcomes of 26 patients who underwent direct ligation of large SRSs during LT. Direct ligation of large SRS was applied in poor portal flow during LT. We performed temporary test clamping of the SRS before direct ligation and applied PV pressure monitoring in patients who showed signs of portal hypertension, such as bowel edema. We retrospectively reviewed and evaluated their clinical outcomes. Among 843 patients who underwent LT between 2010 and 2015, 26 (3.1%) underwent direct ligation of SRS without any intraoperative event. Mean preoperative Model for End-Stage Liver Disease score was 16.7 ± 9.0. The main PV diameter on preoperative computed tomography was 8.3 ± 3.4 mm (range, 3.0-14.0 mm). SRS was easily identified at just below the distal pancreas and beside the inferior mesenteric vein in all patients. Accompanying PV thrombectomy was done in 42.3% of patients. Among 26 patients, massive and prolonged ascites was evident in 15.4% (n = 4) postoperatively. They were all living donor LT recipients with a small PV diameter (4.0-6.7 mm). Except for 1 patient who underwent splenic artery embolization, ascites was tolerable and well controlled by conservative management. There was a 7.7% rate of major complications related to direct ligation, including reoperation due to combined ligation of SRS along with a left renal vein at the confluence. Except for 1 hospital mortality due to sepsis, 25 patients (96.2%) are alive with no evidence of further PV complications. In conclusion, direct ligation of large SRS during LT is a safe and feasible method to overcome the effects of a large SRS. Liver Transplantation 23 899-906 2017 AASLD.

Review of the surgical approach to prevent small-for-size syndrome in recipients after left lobe adult LDLT

Left lobe liver grafts increase the donor safety in adult-to-adult living-donor liver transplantation (ALDLT). However, the left lobe graft provides about 30-50 % of the required liver volume to adult recipients, which is insufficient to sustain their metabolic demands, which can lead to small-for-size syndrome (SFSS). Transient portal hypertension and microcirculatory hemodynamic derangement, apart from outflow obstruction, during the first week after reperfusion are the critical events associated with small-for-size graft transplantation. The incidence of SFSS in left lobe ALDLT can be decreased by increasing the left lobe graft volume by effective utilization of the caudate lobe with preserved vascular supply, by modulating the portal pressure with splenectomy or a porto-systemic shunt or by hepatic venous outflow reconstruction to prevent the development of venous congestion. In this review, we discuss the pathophysiology of SFSS and the various surgical strategies that can be performed to prevent SFSS in an effort to enhance the donor safety during living-donor liver transplantation.

Method for spontaneous constriction and closure of portocaval shunt using a ligamentum teres hepatis in small-for-size graft liver transplantation

BACKGROUND

We have developed a new portocaval (PC) shunt creation technique for use in small-for-size (SFS) graft liver transplantations. PC shunts are already used to avoid SFS graft syndrome in cases of adult-to-adult living donor liver transplantation (LDLT), but the current method of creating these shunts is subject to two problems: reportal hypertension and liver dysfunction after premature ligation of the PC shunt; and graft atrophy and liver dysfunction because of the loss of portal venous flow late in the recovery period after LDLT.

METHODS

Our new technique avoids these two problems simultaneously by using the interposed obliterated ligamentum teres hepatis (LTH) to create the PC shunt, then obstructing the PC shunt after regeneration of the liver graft.

RESULTS

We have used this technique in four cases. In all cases, portal venous pressures after shunting were lower than those before shunting, and PC shunts with lower portal pressure were obstructed faster than that with higher portal pressure.

CONCLUSION

Our results suggest that the LTH can function as a shape memory graft to reduce portal venous flow after regeneration of the graft liver. Using the LTH to create a PC shunt might help to prevent both SFS graft syndrome early in the recovery period after LDLT and loss of portal venous flow late in the recovery period.

The new method of time-lag ligation for portosystemic shunt using coronary artery bypass graft occluder for adult living donor liver transplantation

We performed a living donor liver transplantation (LDLT) for a 57-year-old man who had end-stage liver failure with portal hypertension and an inferior mesenteric vein-left testicular vein (IMV-LTV) shunt. At operation, we did not clamp the shunt but encircled it with a coronary artery bypass graft (CABG) occluder (Sumitomo Bakelite K.K., Japan), which was passed outside the body through the abdominal wall to time-lag ligation (TLL). On postoperative day (POD) 5, we observed decreased portal flow. We performed TLL of the shunt using the CABG occluder without re-laparotomy. The portal flow increased, while the portal vein pressure increased slightly. In LDLT, portosystemic shunt has been reported to be a cause of portal thrombus formation or graft liver atrophy due to decreased PV flow in the mid postoperative period. However, perioperative ligation of a portosystemic shunt may prevent regeneration of the grafted liver because of excessive portal hypertension. Therefore the technique of time-lag ligation of a portosystemic shunt using a CABG occluder may be a minimally invasive, useful method to achieve physiological liver graft regeneration.

The right small-for-size graft results in better outcomes than the left small-for-size graft in adult-to-adult living donor liver transplantation

BACKGROUND

The recent outcome of adult-to-adult living donor liver transplantation (ALDLT) using small-for-size grafts (SFSGs; GRWR <0.8%) has been excellent after right grafts were exclusively used in large-volume ALDLT centers.

METHODS

We compared the outcome of ALDLTs using 11 right SFSGs (group R) with that using 18 left SFSGs (group L) of our center. The dysfunction of graft was defined dysfunction as hyperbilirubinemia (>5 mg/dl), prolonged prothrombin time (>2 INR), or uncontrolled ascites (>1,000 ml/day) on 3 consecutive days in posttransplant 7 days, and the dysfunction score (DS; the sum of points given per each sign) of the graft was used to describe the SFSG dysfunction severity.

RESULTS

The pretransplant recipient status was similar between the groups, but the 1-year mortality rate was 0% in group R and 33.3% (n = 6) in group L (p = 0.038). The ICU stay was longer in group L (20 days) than in group R (11 days; p = 0.004). Hyperbilirubinemia in group R vs. L was noted in 54.5% vs. 50%, prolonged prothrombin time in 18.2% vs. 50%, and uncontrolled ascites in 54.5% vs. 100%. The DS was lower in group R than in group L (1.3 vs. 2; p = 0.007). The DS was zero in four right liver recipients. On multivariate analysis, the only factor affecting DS was the graft side.

CONCLUSION

The clinical signs of SFSG dysfunction were less arduous and there was no 1-year mortality in cases in group R. Therefore, the right SFSG may be used for ALDLT in the future base on the transplant center's experience.

Current concept of small-for-size grafts in living donor liver transplantation

The extended application of living donor liver transplantation (LDLT) has revealed the problem of graft size mismatching called "small-for-size (SFS) graft syndrome." The initial trials to resolve this problem involved increasing the procured graft size, from left to right, and even extension to include a right lobe graft. Clinical cases of living right lobe donations have been reported since then, drawing attention to the risks of increasing the liver volume procured from a living donor. However, not only other modes of increasing graft volume such as auxiliary or dual liver transplantation, but also control of the increased portal pressure caused by an SFS graft, such as a portosystemic shunt or splenectomy, have been trialed with some positive results. To establish an effective strategy for transplanting SFS grafts and preventing SFS graft syndrome, it is essential to have precise knowledge and tactics to evaluate graft quality and graft volume, when performing these LDLTs with portal pressure control. We reviewed the updated literature on the pathogenesis of and strategies for using SFS grafts.

Selective hemi-portocaval shunt based on portal vein pressure for small-for-size graft in adult living donor liver transplantation

We developed an algorithm of graft selection in which left lobe donation is considered primarily if the graft-to-recipient weight ratio (GRWR) is estimated to be greater than 0.6% in preoperative volumetry with utilization of a hemi-portocaval shunt (HPCS) based on portal vein pressure (PVP) more than 20 mmHg at the time of laparotomy. A total of 11 consecutive adult living donor liver transplantations with small-for-size graft according to our graft selection algorithm were performed between December 2005 and August 2007. Ten patients required HPCS using a vein graft all survived without small-for-size syndrome (SFSS) and shunt complications with a median follow-up of 296 days. One patient without HPCS died of chronic vascular rejection. In all cases, PVP were regulated successfully under 20 mmHg by HPCS. Graft volume reached in mean 84.3% of standard liver volume in right lobe grafts and mean 95.4% in left lobe grafts at 3 months after liver transplantation. Actuarial rate of shunt patency at 1, 3, 6 months and 1 year were 80%, 55%, 26% and 20%, respectively. Selective HPCS based on PVP is an effective procedure and results in excellent patient and graft survival with avoidance of SFSS in grafts greater than 0.6% of GRWR.

Beneficial Effect of Partial Portal Decompression Using the Inferior Mesenteric Vein for Intractable Gastroesophageal Variceal Bleeding in Patients With Liver Cirrhosis

BACKGROUND

Use of the inferior mesenteric vein (IMV) for partial portal decompression has not been recommended as a first-line option for intractable gastroesophageal variceal bleeding because of the thin diameter of the vein. Although these indications remain relevant, few reports have compared partial portal decompression using the IMV with other therapies. We propose that partial portal decompression using the IMV is a useful alternative treatment for intractable variceal bleeding.

METHODS

We performed partial portal decompression using the IMV in eight patients with intractable variceal bleeding that had been uncontrolled using medical and endoscopic therapies. All patients were classified into Child's class B or C. The surgical data, morbidity, and mortality were assessed.

RESULTS

Mean portal venous pressure significantly decreased from 26.9 +/- 2.0 mmHg before the surgery to 19.8 +/- 3.9 mmHg after the surgery. The operative mortality rate was 0%. The mean duration of hospital stay was 25.5 +/- 13.3 days. Although one patient experienced recurrent bleeding, shunt patency was well maintained in all patients during the follow-up period (mean 28.9 +/- 14.1 months). Six patients are still alive and well without ascites or hepatic encephalopathy. Two of the Child's class C patients who underwent emergency shunt died owing to hepatic decompensation.

CONCLUSION

Partial portal decompression using the IMV can be a safe, effective way to treat intractable variceal bleeding in patients with liver cirrhosis. However, use of the shunt procedure may have the most survival benefits for cirrhotic patients with preserved liver function.