Inferior vena cava encirclement by caudate lobe hypertrophy: evaluation by MRI and CT and its impact on caval preservation during orthotopic liver transplantation

European validation of the classification for the anticipated difficulty of liver transplantation

BACKGROUND

Appropriate risk stratification for the difficulty of liver transplantation (LT) is essential to guide the selection and acceptance of grafts and avoid morbidity and mortality.

METHODS

Based on 987 LTs collected from 5 centers, perioperative outcomes were analyzed across the 3 difficulty levels. Each LT was retrospectively scored from 0 to 10. Scores of 0-2, 3-5 and 6-10 were then translated into respective difficulty levels: low, moderate and high. Complications were reported according to the comprehensive complication index (CCI).

RESULTS

The difficulty level of LT in 524 (53%), 323 (32%), and 140 (14%) patients was classified as low, moderate and high, respectively. The values of major intraoperative outcomes, such as cold ischemia time (p = 0.04) and operative time (p < 0.0001) increased gradually with statistically significant values among difficulty levels. There was a corresponding increase in CCI (p = 0.04), severe complication rates (p = 0.05) and length of ICU (p = 0.01) and hospital (p = 0.004) stays across the different difficulty levels.

CONCLUSION

The LT difficulty classification has been validated.

Temporary Portocaval Shunt Provides Superior Intraoperative Hemodynamics and Reduces Blood Loss and Duration of Surgery in Live Donor Liver Transplantation: A Randomized Control Trial

OBJECTIVE

To compare intraoperative hemodynamic parameters, blood loss, renal function, and duration of surgery with and without temporary portocaval shunt (TPCS) in live donor liver transplantation (LT) recipients. Secondary objectives were postoperative early graft dysfunction, morbidity, mortality, total intensive care unit, and hospital stay.

BACKGROUND

Blood loss during recipient hepatectomy for LT remains a major concern. Routine use of TPCS during LT is not yet elucidated.

METHODS

This study is a single-center, open-label, randomized control trial. The sample size was calculated based on intraoperative blood loss. After exclusion, a total of 60 patients, 30 in each arm (TPCS vs no TPCS) were recruited in the trial.

RESULTS

The baseline recipient and donor characteristics were comparable between the groups. The median intraoperative blood loss ( P = 0.004) and blood product transfusions ( P < 0.05) were significantly less in the TPCS group. The TPCS group had significantly improved intraoperative hemodynamics in the anhepatic phase as compared with the no TPCS group ( P < 0.0001), requiring significantly less vasopressor support. This led to significantly better renal function as evidenced by higher intraoperative urine output in the TPCS group ( P = 0.002). Because of technical simplicity, the TPCS group had significantly fewer inferior vena cava injuries (3.3 vs 26.7%, P = 0.026) and substantially shorter hepatectomy time and total duration of surgery (529.4 ± 35.54 vs 606.83 ± 48.13 min, P < 0.0001). The time taken for normalization of lactate in the immediate postoperative period was significantly shorter in the TPCS group (median, 6 vs 13 h; P = 0.04). Although postoperative endotoxemia, major morbidity, 90-day mortality, total intensive care unit, and hospital stay were comparable between both groups, tolerance to enteral feed was earlier in the TPCS group.

CONCLUSIONS

In live donor LT, TPCS is a simple and effective technique that provides superior intraoperative hemodynamics and reduces blood loss and duration of surgery.

Perceptions of surgical difficulty in liver transplantation: A European survey and development of the Pitié-Salpêtrière classification

BACKGROUND

Significant variations exist regarding the definition of difficult liver transplantation. The study goals were to investigate how liver transplant surgeons evaluate the surgical difficulty of liver transplantation and to use the identified factors to classify liver transplantation difficulty.

METHODS

A Web-based online European survey was presented to liver transplant surgeons. The survey was divided into 3 parts: (1) participant demographics and practices; (2) various situations based on recipient, liver disease, tumor treatment, and technical factors; and (3) 8 real-life clinical vignettes with different levels of complexity. In part 3 of the survey, respondents were asked whether they would perform liver transplantation but were not aware that these patients eventually underwent liver transplantation.

RESULTS

A total of 143 invites were sent out, and 97 (67.8%) participants completed the survey. Most participants considered previous spontaneous bacterial peritonitis, previous supra-mesocolic surgery, hypertrophy of segment I, and obesity to be recipient factors for high-difficulty liver transplantation. Most participants considered liver transplantation to be challenging in patients with Budd-Chiari syndrome, Kasai surgery, polycystic liver disease, diffuse portal vein thrombosis, and a history of open hepatectomy. The proportion of participants indicating that liver transplantation was warranted varied across the 8 cases, from 69% to 100%. Our classification of the surgical difficulty of liver transplantation employed these recipient-related, surgical history-related, and liver disease-related variables and 3 difficulty groups were identified: low, intermediate, and high difficulty groups.

CONCLUSION

This survey provides an overview of the surgical difficulty of various situations in liver transplantation that could be useful for further benchmark and textbook outcome studies.

Comparison of the modified piggyback with standard piggyback and conventional orthotopic liver transplantation techniques: a network meta-analysis

BACKGROUND

In conventional orthotopic liver transplantation (OLT), the recipient's retrohepatic inferior vena cava (IVC) is completely clamped and replaced with the donor IVC. The piggyback technique has been used to preserve venous return, either via an end-to-side or standard piggyback (SPB), or via a side-to-side or modified piggyback (MPB) anastomosis, using a venous cuff from the recipient hepatic veins with partially clamping and preserves the recipient's inferior vena cava. However, whether these piggyback techniques improve the efficacy of OLT is unclear. To address the low quality of the available evidence, we performed a meta-analysis to compare the efficacy of conventional, MPB, and SPB techniques.

METHODS

Literature was searched in Medline and Web of Science databases for relevant articles published until 2021 without any time restriction. A Bayesian network meta-analysis was performed to compare the intra- and postoperative outcomes of conventional OLT, MPB, and SPB techniques.

RESULTS

Forty studies were included, comprising 10,238 patients. MPB and SPB had significantly shorter operation times and fewer transfusions of red blood cell and fresh frozen plasma than conventional techniques. However, there were no differences between MPB and SPB in operation time and blood product transfusion. There were also no differences in primary non-function, retransplantation, portal vein thrombosis, acute kidney injury, renal dysfunction, venous outflow complications, length of hospital and intensive care unit stay, 90-day mortality rate, and graft survival between the three techniques.

CONCLUSION

MBP and SBP techniques reduce the operation time and need for blood transfusion compared with conventional OLT, but postoperative outcomes are similar. This indicates that all techniques can be implemented based on the experience and policy of the transplant center.

Defining Surgical Difficulty of Liver Transplantation

OBJECTIVE

To define technically Diff-LT.

SUMMARY OF BACKGROUND DATA

Currently, there is no acknowledged definition of Diff-LT.

METHODS

This retrospective study included all first consecutive liver-only transplantations performed in 2 centers from 2011 to 2015. Diff-LT was defined as the combination of the number of blood units transfused, cold ischemia time, and duration of operation, all at or above the median value of the entire population. The correlation of Diff-LT with short- (including the comprehensive complication index) and long-term outcomes was assessed. Outcomes were also compared to the 90-day benchmark cutoffs of LT. Predictors of Diff-LT were identified by multivariable analysis, first using only recipient data and then using all recipient, donor, graft, and surgical data.

RESULTS

The study population included 467 patients. The incidence of Diff- LT was 18.8%. Diff-LT was associated with short-term outcomes, including the comprehensive complication index and mortality, but not with patient or graft long-term survival. Previous abdominal surgery, intensive care unitbound at the time of LT, split graft use, nonstandard arterial reconstruction, and porto-systemic shunt ligation were independent predictors of Diff-LT. The proportion of variables below the corresponding LT 90-day benchmark cutoffs was 8/13 (61.5%) for non-Diff-LT, and 4/13 (30.8%) for Diff-LT.

CONCLUSIONS

Diff-LT, as defined, occurred frequently. Adjusting modifiable variables might decrease the risk of Diff-LT and improve the postoperative course. This definition of Diff-LT might be useful for patient information, comparison between centers and surgeons, and as a metric in future trials.

Development of a preoperative score to predict surgical difficulty in liver transplantation

BACKGROUND

A difficulty score to predict intraoperative surgical complexity in liver transplantation has never been developed. The aim of this study was to assess factors associated with a difficult liver transplant and develop a score to predict difficult surgery.

METHODS

All patients undergoing deceased donor whole liver transplantation from 2012 to 2019 at a single center were included. Estimated intraoperative blood loss (mL/kg) and surgery duration (skin-to-arterial reperfusion time) were used as surrogates of difficulty. Based on these variables, the study population was divided into 2 groups: high risk and standard risk of difficulty. Univariate and multivariate analyses were performed to identify predictors associated with a demanding liver transplantation and develop a difficulty score.

RESULTS

A total of 515 patients were included in the study population, and 101 (20%) were considered difficult operations. Patients with a higher risk of difficulty showed a significantly higher rate of Clavien-Dindo ≥III complications (50.5% vs 24.4%, P = .001) and a longer hospital stay (19 vs 16 days, P = .001). Preoperative factors associated with difficulty were retransplantation (odds ratio 4.34, P = .001), preoperative portal vein thrombosis (odds ratio 3.419, P = .001), previous upper abdominal surgery (odds ratio 2.161, P = .003), spontaneous bacterial peritonitis (odds ratio 1.985, P < .02), and prior variceal bleeding (odds ratio 1.401, P = .051). A 10-point difficulty score was created, showing a negative predictive value of 84% at 4 points.

CONCLUSION

Difficult liver transplantation surgery, as assessed by skin-to-arterial reperfusion time and estimated blood loss, is associated with worse perioperative outcomes. We developed a simple score with clinical preoperative variables that predicts difficult surgery, and therefore, it may help to optimize allocation policies and perioperative logistics.

Pre-operative CT scan helps predict outcome after liver transplantation for acute-on-chronic grade 3 liver failure

OBJECTIVES

The aim of this study was to identify the prognostic value of pre-operative imaging to predict post-transplantation survival in critically ill cirrhotic patients with severe acute-on-chronic liver failure (ACLF).

METHODS

Patients with grade 3 ACLF who underwent liver transplantation between January 2010 and January 2020 and with available contrast-enhanced abdominal computed tomography (CT) performed less than 3 months before LT were retrospectively included (n = 82). Primary endpoint was 1-year mortality. Imaging parameters (sarcopenia, liver morphology and volumetry, and signs of portal hypertension) were screened and tested to build a prognostic score.

RESULTS

In the multivariate analysis, three independent CT-derived prognostic factors were found: splenomegaly (p = 0.021; HR = 5.6 (1.29-24.1)), liver atrophy (p = 0.05; HR = 2.93 (1.01-10.64)), and vena cava diameter ratio (p < 0.0001; HR = 12.7 (3.4-92)). A simple prognostic score was proposed, based on the presence of splenomegaly (5 points), liver atrophy (5 points), and vena cava diameter ratio < 0.2 (12 points). A cutoff at 10 points distinguished a high-risk group (score > 10) from a low-risk group (score ≤ 10) with 1-year survival of 27% vs. 67% respectively (p < 0.001). It was found to be an independent predictive factor in association with the Transplantation for ACLF3 Model (TAM) score.

CONCLUSION

Pre-transplantation contrast-enhanced abdominal CT has a significant impact on selection of patients in ACLF3 in order to predict 1-year survival after LT.

KEY POINTS

• Splenomegaly, liver atrophy, and vena cava diameter ratio are independent CT-derived prognostic factors after transplantation for severe acute-on-chronic liver failure. • A simple CT-based prognostic score is an independent predictive factor, complementary to clinical and biological parameters. • The use of the CT-derived score allows stratification based on 1-year mortality for patients with otherwise uncertain prognosis with clinical and biological parameters alone.

The learning curve for piggyback liver transplantation: identifying factors challenging surgery

BACKGROUND

This study aimed to quantify the learning curve of piggyback liver transplantation and to identify factors that impact the operative time and blood transfusion during the learning curve.

METHODS

A retrospective review was performed on consecutive cases of patients' first piggyback liver transplantations that were performed by a single surgeon. The learning curve for the operative time was evaluated using the cumulative sum method.

RESULTS

There were 181, consecutive, first-time piggyback liver transplantations. The median operative time was 345 minutes (range: 180-745 minutes) with a median transfusion rate of 4 packed red blood cell units (range: 0-23 units). The cumulative sum learning curve identified 3 phases: an initial phase (1-70 piggyback liver transplantations), a plateau phase (71-101 piggyback liver transplantations), and a stable phase (102-181 piggyback liver transplantations). Over the 3 phases, there were significant decreases in the median duration of the surgery (388.8 vs 344.8 vs 326.9 minutes; P = .004, P = .0004, P ≤ .0001) and the number of red blood cell units transfused (6.00 vs 3.90 vs 3.71; P = .02, P = .79, P = .0006). Multivariable analysis identified that the following factors impacted the operative time: surgeon experience (P = .00006), previous upper abdominal surgery (P = .01), portocaval shunt fashioning (P = .0003), early portal section (P = .00001), multiple arterial graft reconstruction (P = .03), and the length of the retrohepatic inferior vena covered by segment 1 (P = .0006). Independent risk factors for increased blood loss were surgeon experience (P = .0001), previous upper abdominal surgery (P = .002), the retrohepatic inferior vena cava encirclement by segment 1 (P = .0001), severe portal hypertension (P = .01), early portal section (P = .001), and low prothrombin time (P = .00001).

CONCLUSION

Easily identifiable factors related to recipients (segment 1 morphology, previous upper abdominal surgery, severe portal hypertension) and to surgeon (operative experience, portocaval shunt fashioning, early portal section, and multiple arterial reconstructions) impact operative time and blood loss during the learning curve of piggyback liver transplantation. These factors can be used for grading the difficulties of liver transplantation to tailor the surgical strategy.

Can Preoperative Multidetector Computed Tomography Identify Predictive Features of Difficult Native Hepatectomy at Liver Transplantation?

BACKGROUND

Native hepatectomy represents the most demanding surgical step during orthotopic whole liver transplantation (LT). The surgical risk assessment of LT candidates is currently mainly based on clinical and laboratory data, but even preoperative imaging data may be predictive of a complex native hepatectomy.

METHODS

A retrospective study on a cohort of 110 LT recipients was conducted. The radiologic variables investigated on pre-LT multidetector computed tomography scan were the length of the retrohepatic inferior vena cava (IVC-L), volume of the dorsal liver sector (DLS-V), complete encirclement of the IVC by the DLS (IVC-CE), max diameter of the native liver (L-D), max diameter of the spleen (S-D), and presence of large spontaneous portosystemic shunts (SPSS). The parameters defining complex native hepatectomy were the operative time, number of red blood cell (RBC) units transfused, IVC replacement technique switch, and post-LT relaparotomy for major bleeding.

RESULTS

In a multivariate analysis, the operative time was predicted by hepatocellular carcinoma (HCC) diagnosis (regression coefficient [RC]: 18.237, P = .009), S-D (RC: 3.733, P = .007), and IVC-CE (RC: 20.174, P = .01); the RBC units transfused by an history of gastroesophageal variceal bleeding (RC: 2.503, P = .039), Model for End-Stage Liver Disease (MELD) score (RC: .259, P = .039), and L-D (RC: -0.519, P = .027); the switch to a IVC replacement technique by L-D (odds ratio [OR]: 0.641, P = .028) and IVC-L (OR: 1.065, P = .023); and the relaparotomy for bleeding by L-D (OR: 0.632, confidence interval [CI]: 0.437 to 0.916, P = .015).

CONCLUSIONS

Pre-LT multidetector computed tomography (MDCT) seems to be a very useful tool in the surgical risk assessment of LT candidates.

A South Indian Cadaveric Study About the Relationship of Hepatic Segment of Inferior Vena Cava with the Liver

INTRODUCTION

Inferior Vena Cava (IVC) is the largest vein of the body. It runs vertically upwards in the abdomen, behind the liver. Its course is very constant in relation to liver. However, the amount of liver parenchyma related to it can vary from person to person. The data regarding its course and relations may be very useful to radiologists and surgeons during surgical treatment procedures for Budd-Chiari syndrome, liver carcinoma, liver transplant, venous cannulations and many other clinical procedures.

AIM

Aim of this study was to document the incidence of straight and curved course of IVC in relation to liver and also to note the pattern in which the liver tissue was related to the IVC.

MATERIALS AND METHODS

In the current study, 95 adult cadaveric livers were observed; specifically to study the course/direction of the hepatic segment of IVC in relation to the liver. The extent of liver tissue related to various aspects of IVC was also studied. The course of the IVC was classified as straight and curved; and the relationship of liver parenchyma to the IVC was classified into 6 categories. The data was expressed as percentage incidence.

RESULTS

In 78.94% cases, the IVC had a straight course in relation to the liver; whereas in 21.06% cases, it had a left sided curve (concavity of the curve towards the caudate lobe) in its course. In 6.31% cases, IVC travelled in a tunnel, being encircled by the liver parenchyma all around; in 36.84% cases, it was covered by liver parenchyma on front and sides so that only posterior surface of IVC was visible; in 3.15% cases it was covered by liver tissue on front, sides and also partly on posterior aspect; in 50.52% of cases, its anterior surface, sides and left edge of the posterior surface was covered by liver tissue; and in 3.15% cases it was covered only from the front by the liver tissue.

CONCLUSION

The data being reported here might be useful for surgeons while planning and executing various hepatic surgeries and also to the radiologists in planning and performing venous cannulation and therapeutic procedures. Since in many livers, the curvature of IVC was associated with enlarged caudate lobe, the curved IVC could hint about the increase in the volume of caudate lobe or liver itself.

Vena cava encirclement predicts difficult native hepatectomy

Recipient hepatectomy is a challenging liver transplantation (LT) procedure that has life-threatening complications. The current predictive mortality clinic-biological scores (Child/Model for End-Stage Liver Disease [MELD]) do not take into consideration the recipient's liver anatomy. The aim of this study was to evaluate the impact of the dorsal sector anatomy of a cirrhotic liver on the morbidity/mortality rates of hepatectomy. A multicenter retrospective study (clinic-biological and morphologic) was performed from 2013 to 2014. The degree of encirclement of the inferior vena cava (IVC) by the dorsal sector of the liver was measured. The study population included 320 patients. Seventy-four (23%) patients had complete IVC encirclement. A correlation (P = 0.01) has been reported between the existence of a circular dorsal sector and the number of transfusions during LT (4 packed red blood cell [PRBC] transfusions in the group without IVC versus 7 PRBC transfusions in the other group). The existence of such anatomy increases the relative risk of early reoperation for IVC bleeding by 31% (P = 0.05). There is a correlation between alcoholic cirrhosis and dorsal-sector hypertrophy (126 cc versus 147.5 cc; P = 0.05). Concerning surgical time, we found no significant between-group differences. Compared to the severity of cirrhosis, an inverse correlation was observed between the MELD and Child scores and the dorsal sector hypertrophy (P < 0.001). No significant difference in terms of transfusion was found between the temporary portocaval shunt group (n = 168) and the other group (n = 152). The presence of a circular sector is associated with an increased risk of hemorrhage during hepatectomy, as well as an immediate postoperative risk of reoperation. Liver Transplantation 22 906-913 2016 AASLD.

Short-term Total Hepatic Vascular Exclusion in Difficult Caudate Lobe Dissection in Living-donor Liver Transplantation Recipients

BACKGROUND

Recipient hepatectomy can be complicated by severe bleeding during caudate lobe dissection in living-donor liver transplantation (LDLT), especially when the inferior vena cava is encased or with dense adhesions from prior interventions. Total hepatic vascular exclusion (TVE) including total hepatic inflow (Pringle maneuver) and occlusion of supra- and infra-hepatic inferior vena cava during the partial hepatectomy has been studied well, but it has not been mentioned regarding recipient hepatectomy in LDLT. The aim of this study is to evaluate hemodynamic impact and surgical outcome by using the technique of TVE in LDLT.

METHODS

From April 2010 to June 2010, 30 consecutive LDLT recipients at Kaohsiung Chang Gung Memorial Hospital with TVE (TVE group, n = 14) or without TVE (non-TVE group, n = 16) for the caudate lobe dissection were analyzed retrospectively.

RESULTS

The TVE group had a mean decrease in systolic blood pressure and cardiac index of 21% and 41% during caudate dissection in recipient hepatectomy, respectively. The TVE group had shorter time for caudate mobilization and less blood loss compared with the non-TVE group (3904 mL vs. 5650 mL, P = .461). Two patients in the non-TVE group were shifted to TVE as a salvage procedure to control bleeding. Three patients in the non-TVE group underwent relaparotomy for homeostasis.

CONCLUSIONS

Short-term TVE is a technically feasible procedure and should be considered during recipient hepatectomy with difficult caudate lobe dissection in LDLT to create a bloodless surgical field. Most patients tolerated the TVE without hemodynamic impact under anesthetic management.