Orthotopic liver transplantation without venovenous bypass using the conventional and piggyback techniques

Deceased Donor Liver Transplantation: Techniques and Surgical Anatomy

Deceased liver donor transplantation is increasing in prevalence resulting in larger volumes of posttransplant imaging studies. Radiologists should familiarize themselves with the spectrum of normal posttransplant anatomy. The key findings can be categorized into 4 systems reconstructed during surgery: hepatic venous, portal venous, hepatic arterial, and biliary ductal systems. Here we discuss the imaging findings seen with the most common surgical techniques, those that can be misidentified as complications, and some less common variations resulting from different surgical techniques.

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.

Which cava anastomotic techniques are optimal regarding immediate and short-term outcomes after liver transplantation: A systematic review of the literature and expert panel recommendations

BACKGROUND

It has long been debated whether cava anastomosis should be performed with the piggyback technique or cava replacement, with or without veno-venous bypass (VVB), with or without temporary portocaval shunt (PCS) in the setting of liver transplantation.

OBJECTIVES

To identify whether different cava anastomotic techniques and other maneuvers benefit the recipient regarding short-term outcomes and to provide international expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

A systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel (CRD42021240979).

RESULTS

Of 3205 records screened, 307 publications underwent full-text assessment for eligibility and 47 were included in qualitative synthesis. Four studies were randomized control trials. Eighteen studies were comparative. The remaining 25 were single-center retrospective noncomparative studies.

CONCLUSION

Based on existing data and expert opinion, the panel cannot recommend one cava reconstruction technique over another, rather the surgical approach should be based on surgeon preference and center dependent, with special consideration toward patient circumstances (Quality of evidence: Low | Grade of Recommendation: Strong). The panel recommends against routine use of vevo-venous bypass (Quality of evidence: Very Low | Grade of Recommendation: Strong) and against the routine use of temporary porto-caval shunt (Quality of evidence: Very Low | Grade of Recommendation: Strong).

Preoperative echocardiography as a prognostic tool for liver transplant in patients with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) presents with a hypertrophied left ventricle (LV). It is often associated with LV outflow tract obstruction (LVOTO) and a risk for sudden death. This study aimed to describe outcomes of patients with HCM who underwent liver transplant (LT).

METHODS

A retrospective review was conducted for patients diagnosed with HCM undergoing LT. Patient characteristics, preoperative echocardiography results, HCM risk of sudden cardiac death prediction model score, and 5-year mortality were examined. A univariable Cox proportional hazards model was used to evaluate the association between risk factors and 5-year mortality. All tests were two-sided with the alpha level set at .05.

RESULTS

Twenty-nine patients were included in the analysis. Six patients (21%) had a perioperative cardiopulmonary complication. The 5-year survival rate was 61% (95% CI, 45-82). The analyzed risk factors showed that 5-year post-LT survival was significantly predicted by maximal LV outflow tract gradient at rest > 60 mmHg (hazard ratio, 1.04 [95% CI, 1.01-1.06]).

CONCLUSIONS

Preoperative LV outflow tract resting gradient > 60 mmHg was associated with 5-year post-LT mortality. The results suggest the severity of LVOTO identified by echocardiography is a prognostic tool for patients with HCM after LT.

An Alternative Surgical Technique of Native Hepatectomy in Liver Transplantation

Background

Orthotopic liver transplantation has become the procedure of choice for end-stage liver disease. There are 3 commonly used methods of vena cava anastomosis. Here, we report a new technique for native hepatectomy.

Material/Methods

The data of 12 patients who underwent orthotopic liver transplantation using a new surgical technique were retrospectively collected for analysis. The new separation and reconstruction surgical technique mainly involved the second portal isolation and hepatectomy that followed. We performed recipient liver resection without the occlusion of the inferior vena cava, which was then followed by classic, piggyback, modified piggyback, or side-to-side orthotopic liver transplantation. The graft function index and complications were collected after transplantation.

Results

The length of the anhepatic phase was 30.92±9.1 min. Alanine transaminase (ALT) levels were 138 to 2027 U/L, with a median of 361.5 U/L. The ALT levels of all patients gradually decreased to normal levels 7 to 10 days after surgery. Only 2 recipients had elevated levels of ALT higher than 1000 U/L. Four of 12 patients did not require red blood cell transfusion during surgery. Four patients appeared to have early allograft dysfunction, while others recovered smoothly.

Conclusions

This new surgical technique may shorten the anhepatic phase and decrease blood loss volume, aiding the success of liver transplant surgery. It can be used for most patients and does not increase the risk of complications or impair prognosis.

Piggyback or Cava Replacement: Which Implantation Technique Protects Liver Recipients From Acute Kidney Injury and Complications?

The cava-preserving piggyback (PB) technique requires only partial cava clamping during the anhepatic phase in liver transplantation (LT) and, therefore, maintains venous return and may hemodynamically stabilize the recipient. Hence, it is an ongoing debate whether PB implantation is more protective from acute kidney injury (AKI) after LT when compared with a classic cava replacement (CR) technique. The aim of this study was to assess the rate of AKI and other complications after LT comparing both transplant techniques without the use of venovenous bypass. We retrospectively analyzed the adult donation after brain death LT cohort between 2008 and 2016 at our center. Liver and kidney function and general outcomes including complications were assessed. Overall 378 transplantations were analyzed, of which 177 (46.8%) were performed as PB and 201 (53.2%) as CR technique. AKI occurred equally often in both groups. Transient renal replacement therapy was required in 22.6% and 22.4% comparing the PB and CR techniques (P = 0.81). Further outcome parameters including the complication rate were similar in both cohorts. Five-year graft and patient survival were comparable between the groups with 81% and 85%, respectively (P = 0.48; P = 0.58). In conclusion, both liver implantation techniques are equal in terms of kidney function and overall complications following LT.

Weaning of Veno-venous Bypass in Liver Transplantation: A Single Center Experience

BACKGROUND

Veno-venous bypass (VVB) has been used in liver transplantation (LT) to minimize hemodynamic instability during caval anastomosis of anhepatic phase. With the introduction of the piggyback (PB) technique, which is a caval-sparing technique, the use of VVB progressively decreased over the world. The aim of this study was to introduce our experience using VVB with the focus on its weaning process.

METHODS

A total of 300 consecutive LT cases from May 1996 to November 2003 were examined. Except for pediatric LT, 242 LT cases were investigated to evaluate the trends in VVB use, surgical technique, the amount of transfusion requirements, and durations of operation and anhepatic phase.

RESULTS

For the early 100 LT cases, VVB was used in 97.5% of recipients, especially in all the recipients of deceased donor LT (DDLT). Then, the frequency of VVB use was decreased, and VVB was not used after the 268th recipient. In DDLT, the PB technique was first introduced in the 58th recipient and became a routine procedure of the DDLT since the 191th recipient. Living donor LT was increased, and the amount of transfusion requirement, duration of operation, and duration of anhepatic phase was reduced over time.

CONCLUSIONS

The increasing experience and sophisticated surgical and anesthetic techniques were important factors responsible for the weaning of VVB. The advancement of the PB technique used in living donor LT might be a main factor of its weaning.

Strategies to avoid empiric blood product administration in liver transplant surgery

Massive blood loss has been a dreaded complication of liver transplantation, and the accompanying transfusion is associated with adverse outcomes in the form of decreased patient and graft survival. With advances in both surgical techniques and anesthetic management during transplantation, blood and blood products requirements reduced significantly. However, transfusion practices vary among different centers. The altered coagulation parameters in patients with liver cirrhosis results in a state of “rebalanced hemostasis” and patients are just as likely to clot as they are to bleed. Commonly used coagulation tests do not always reflect this new state and can, therefore, be misleading. Transfusion of blood products solely to correct abnormal parameters may worsen the coagulation status, thus adversely affecting patient outcome. Point-of-care tests such as thromboelastometry more reliably predict the risk of bleeding in these patients and in addition may provide quicker turnaround times compared to routine tests. Perioperative management should also include the possibility of thrombosis in these patients, and the use of low-molecular-weight heparin correlates with better patient survival. This review article aims to highlight the concept of rebalanced hemostasis, limitation of routine coagulation tests, and harmful effect of empiric transfusion of blood products.

Transesophageal ultrasonography during orthotopic liver transplantation: Show me more

The first perioperative transesophageal echocardiography (TEE) guidelines published 21 years ago were mainly addressed to cardiac anesthesiologists. TEE has since expanded its role outside this setting and currently represents an invaluable tool to assess chamber sizes, ventricular hypertrophy, and systolic, diastolic, and valvular function in patients undergoing orthotopic liver transplantation (OLT). Right-sided microemboli, right ventricular dysfunction, and patent foramen ovale (PFO) are the most common intra-operative findings described during OLT. However, left ventricular outflow tract obstruction and left ventricular ballooning syndrome are more difficult to recognize and less frequent. Transesophageal ultrasonography (TEU) during OLT is also underused. Its applications are as follows: (1) assistance in the difficult placement of pulmonary arterial catheters; (2) help with catheterization of great vessels for external veno-venous bypass placement; (3) intra-operative evaluation of surgical liver anastomosis patency, if feasible, through the liver window; and (4) intra-operative investigation of "acute hypoxemia" due to pulmonary and cardiac issues using trans-esophageal lung ultrasound (TELU). The aims of this review are as follows: (1) to summarize the uses of TEE and TEU throughout all phases of OLT, and (2) to describe other new feasible applications.

The Impact of Implantation Time During Liver Transplantation on Outcome: A Eurotransplant Cohort Study

Supplemental digital content is available in the text.

Background

The liver graft quickly rewarms during transplantation when the vascular anastomoses are being performed, potentially impacting on outcomes.

Methods

We investigated the relationship between implantation time and outcome in 5223 recipients of deceased-donor livers transplanted in Eurotransplant (2004-2013). Cox regression analyses were corrected for donor, preservation, and recipient variables. Transplant loss represents all-cause graft failure.

Results

Median implantation time was 41 minutes (interquartile range, 34-51). Implantation time independently associated with transplant loss (adjusted hazard ratio, 1.04 for every 10-minute increase; 95% confidence interval, 1.01-1.07; P = 0.007). The magnitude of the implantation time effect was comparable to the effect of each additional hour of cold ischemia (adjusted hazard ratio, 1.03; 95% confidence interval, 1.02-1.05; P < 0.001). The effect was most pronounced early posttransplant with no evidence of a significant effect beyond 3 months. A similar detrimental effect of implantation time was seen for graft and patient survivals. The increased risk for transplant loss in livers donated after circulatory determination of death could be attributed to donor warm ischemia time.

Conclusions

Implantation time associates with inferior liver transplant outcome in a continuous way. These findings need confirmation and further study of confounding factors is needed so steps toward improving outcomes can be made.

Liver Transplantation Without Venovenous Bypass: Does Surgical Approach Matter?

Background

The use of venovenous bypass in liver transplantation has declined over time. Few studies have examined the impact of surgical approach in cases performed exclusively without venovenous bypass. We hypothesized that advances in liver transplant anesthesia and perioperative care have minimized the importance of surgical approach in the modern era.

Methods

Deceased donor liver transplants at the University of Toronto from 2000 to 2015 were reviewed, all performed without venovenous bypass. First, an unadjusted analysis was performed comparing perioperative outcomes and graft/patient survival for 3 different liver transplant techniques (caval interposition, piggyback, side-to-side cavo-cavostomy). Second, a propensity-matched analysis was performed comparing caval interposition to caval-preserving techniques.

Results

One thousand two hundred thirty-three liver transplants were included in the study. On unadjusted analysis, blood loss, transfusion requirement, postoperative complications, and graft/patient survival were equivalent for the 3 different techniques. To account for possible confounding patient variables, propensity matching was performed. Analysis of the propensity-matched cohorts also demonstrated similar outcomes for caval interposition versus caval-preserving approaches.

Conclusions

In the modern era at centers with a multidisciplinary team, the importance of specific liver transplant technique is minimized. Full or partial cross-clamping of the inferior vena cava is feasible without the use of venovenous bypass.

Comparison of three caval reconstruction techniques in orthotopic liver transplantation: A retrospective review

BACKGROUND

Classic caval reconstruction during liver transplantation involves complete cross-clamping and resection of the recipient inferior vena cava (IVC) followed by donor IVC interposition. Other techniques preserve the IVC, with piggyback (PB) to the hepatic veins or side-to-side (SS) caval anastomosis. Avoidance of cross-clamping may be beneficial for minimizing hemodynamic instability and transfusion requirements.

METHODS

Retrospective review of a provincial transplant database (2007-2011). MELD score was used to measure disease severity. Intraoperative blood loss and volume resuscitation were compared between three caval reconstruction techniques using ANOVA.

RESULTS

200 deceased-donor transplants (Classic:58, PB:72, SS:70) were included. Baseline disease severity was equal. Mean case duration was shorter in the PB technique (Classic:366, PB:306, SS:385 min, p < 0.001). Despite similar blood loss, there was significantly less cell saver return, FFP, platelets, and overall resuscitation volume (Classic:12.8, PB:9.5, SS:13.2 L, p = 0.001) utilized in the piggyback technique.

CONCLUSIONS

The PB technique was faster and used less cell saver return, FFP and platelets, despite similar blood loss. Availability of different caval reconstruction techniques allows for a breadth of options in difficult cases.

Pulmonary injury at the anhepatic phase without veno-venous bypass in portal hypertensive rats

OBJECTIVE

In order to understand the characterization and evolution of pulmonary injury, a portal hypertension rat model was used to imitate the anhepatic phase during standard orthotopic liver transplantation without veno-venous bypass.

METHODS

In this study, 135 healthy male Wistar rats were selected; in which 15 rats were assigned in the normal control (NC) group and the remaining 120 rats were used to establish a recoverable prehepatic portal hypertension model, which were further evenly divided into eight groups after ischemia-reperfusion: portal hypertensive control group (PHTC), R0h, R6h, R12h, R24h, R48h, R72h, and R7d groups. Meanwhile, arterial blood pressure, dry-to-wet weight ratios of the lung, alanine aminotransferase (ALT) level in serum, arterial oxygen pressure (PaO₂), and myeloperoxidase (MPO) activity in lung tissue were measured. Morphology changes of the lung were observed using an optical microscope and a transmission electron microscope.

RESULTS

The portal hypertension rat model was successfully established three weeks after the first operation. These portal hypertensive rats could withstand 1 hour at the anhepatic phase. Pulmonary injury severity increased to the most at 12-24 hours, and decreased to normal at seven days after reperfusion.

CONCLUSION

Ischemia-reperfusion injury is an important mechanism that results in pulmonary injury after liver transplantation. It is safe for portal hypertensive rats to tolerate 1 hour at the anhepatic phase. Pulmonary injury was the most severe within 12-24 hours after ischemia-reperfusion.

Transplantation in autosomal recessive polycystic kidney disease: liver and/or kidney?

Autosomal recessive polycystic kidney disease (ARPKD) is characterized by enlarged kidneys with dilated collecting ducts and congenital hepatic fibrosis. There is a variable rate of progression of kidney and liver disease. Portal hypertension and Caroli's disease occur from liver involvement that contributes to morbidity and mortality. Approximately 40 % of patients have a severe disease phenotype leading to rapid onset of end-stage kidney disease (ESKD) and signs of portal hypertension and the rest may have predominant involvement of either the kidney or liver. It is important for the physician to establish the extent of organ involvement before deciding on the ultimate plan of management, especially when transplantation is required. Isolated renal transplantation can be considered when liver involvement is minimal. If hepatobiliary disease is prominent, and kidney function is preserved, management options are based on individual characteristics. In the presence of significant liver disease and ESKD, consideration should be given to combined liver kidney transplantation, which can be beneficial in eliminating the consequences of both kidney and liver disease. However, this is a complex surgical procedure that needs to be performed at experienced transplant centers. Improvement in surgical techniques has considerably improved short-term graft survival with the added advantage of the liver offering immunologic protection to the kidney allograft.

Caval reconstruction techniques in orthotopic liver transplantation

There are several caval reconstruction techniques currently in use for orthotopic liver transplantation. These include caval replacement or the conventional technique, performed with or without venovenous bypass, piggyback technique with anastomosis with two or three hepatic veins with or without cavotomy and modifications of the piggyback technique including end-to-side and side-to-side cavocaval anastomosis. There are few randomized controlled trials comparing the use of these techniques and our knowledge of their comparability is based on a few multi- and many single-center retrospective and prospective reviews. Although there are advantages and disadvantages for each technique, it is advisable that the surgeon perform the technique with which they have the most the experience and at which they are the most skilled as excellent outcomes can be obtained with any of the caval reconstruction options discussed.

Liver transplantation in transthyretin amyloidosis: issues and challenges

Hereditary transthyretin amyloidosis (ATTR) is a rare worldwide autosomal dominant disease caused by the systemic deposition of an amyloidogenic variant of transthyretin (TTR), which is usually derived from a single amino acid substitution in the TTR gene. More than 100 mutations have been described, with V30M being the most prevalent. Each variant has a different involvement, although peripheral neuropathy and cardiomyopathy are the most common. Orthotopic liver transplantation (OLT) was implemented as the inaugural disease-modifying therapy because the liver produces the circulating unstable TTR. In this review, we focus on the results and long-term outcomes of OLT for ATTR after more than 2063 procedures and 23 years of experience. After successful OLT, neuropathy and organ impairment are not usually reversed, and in some cases, the disease progresses. The overall 5-year survival rate is approximately 100% for V30M patients and 59% for non-ATTR V30M patients. Cardiac-related death and septicemia are the main causes of mortality. Lower survival is related to malnutrition, a longer duration of disease, cardiomyopathy, and a later onset (particularly for males). Deposits, which are composed of a mixture of truncated and full-length TTR (type A) fibrils, have been associated with posttransplant myocardial dysfunction. A higher incidence of early hepatic artery thrombosis of the graft has also been documented for these patients. Liver-kidney/heart transplantation is an alternative for patients with advanced renal disease or heart failure. The sequential procedure, in which ATTR livers are reused in patients with liver disease, reveals that neuropathy in the recipient may appear as soon as 6 years after OLT, and ATTR deposits may appear even earlier. Long-term results of trials with amyloid protein stabilizers or disrupters, silencing RNA, and antisense oligonucleotides will highlight the value and limitations of liver transplantation.

Renal support during liver transplantation: when to consider it?

Patients undergoing orthotopic liver transplantation constitute a difficult-to-treat population. They often have multiorgan dysfunction: acute kidney injury, severe water-electrolyte and acid-base imbalances, systemic inflammatory responses, thrombocytopenia, as well as abnormalities of coagulation and fibrinolysis. All of these disorders may be further exacerbated by the surgical procedure, which is lengthy and technically complex, requiring massive blood product and other fluid infusions with a high risk to develop severe lactic acidosis, hyperkalemia, or cerebral edema. These considerations provide a rationale to institute intraoperative renal replacement therapy (ioRRT), at least for the most critically ill, namely, patients with kidney dysfunction, or those in whom one anticipates intraoperative clinical and technical problems. This article discusses the most common indications and strategies for ioRRT, examining their advantages and disadvantages as well as current experiences.

Conventional versus piggyback techniques: do they have different outcomes?

BACKGROUND

Conventional orthotopic liver transplant includes resection of the recipient's native liver, together with the retrohepatic inferior vena cava, whereas with the piggyback technique, the recipient's vena cava is preserved and the donor's vena cava is anastomosed with the recipient's hepatic veins. So the caval flow is maintained during explantation, but on the other hand, the cava must be dissected completely from the liver, prolonging hepatic excision.

OBJECTIVE

To compare outcomes of conventional versus piggyback techniques. Primary outcomes were serious adverse events or complications, and secondary outcomes were graft survival for 3 and 12 months, quality of life, days in the intensive care unit and in the hospital, and days spent receiving mechanical ventilation.

MATERIALS AND METHODS

From January 3, 2007, to December 31, 2008, 120 liver transplant patients were divided into 2 groups: conventional (n = 93) and piggyback (n = 27).

RESULTS

Intraoperative and postoperative complications, graft survival for 3 and 12 months, quality of life, and hospital stay did not differ significantly between the 2 groups. However, the stay in the intensive care unit (median, 2 vs 3 days; range, 1-101 vs 1-60 days) and the number of days on ventilatory support (median, 1 vs 2 days; range, 0-41 vs 1-60 days) were notably lower in the conventional group.

CONCLUSION

The conventional liver transplant technique had significantly better results than the piggyback technique in terms of length of stay in the intensive care unit and duration of mechanical ventilation.

A comparative study of the classic and piggyback techniques for orthotopic liver transplantation

Background:

The classic technique of hepatectomy with venovenous bypass may cause a longer anhepatic phase and increase the rate of some complications, such as post-operative renal failure and thromboembolic events. But, in some cases, such as tumors and anatomic difficulties, the surgeon is obligated to use the classic technique even though there is some controversy about the safety of this technique without venovenous bypass in liver transplantation. The aim of this study was to compare the results of using the classic technique without venovenous bypass and the piggyback technique for liver transplantation.

Methods:

A retrospective case-series study was conducted on 227 consecutive successful liver transplants, including 55 cases in which the classic technique was used and 172 cases in which the piggyback technique was used. The transplants were performed from March 2010 through June 2011 in the Visceral Transplantation Ward at Namazi Hospital in Shiraz, Iran. The piggyback method was the preferred approach for hepatectomy, but the classic technique without venovenous bypass was performed in cirrhotic cases with anatomic difficulties, when there was a tumor, or when the surgeon preferred it.

Results:

There were no significant differences in post-operative rise in creatinine, decreases in intraoperative blood pressure, transfused packed red blood cells (RBC), or survival rates between the groups. Warm ischemic time (duration that donor liver is out of ice until it’s blood reperfusion in the recipient) was approximately seven minutes longer in the classic group (P = 0), but it was less than 52 minutes, which is an acceptable time for this phase. Hospital stays were shorter in the classic group than in the piggyback group (P = 0.024).

Conclusion:

Although the piggyback technique is the preferred technique for hepatectomy in liver transplantation, the classic technique without venovenous bypass can be used safely in cirrhotic livers when necessary or if the physician prefers it.

Preoperative variables associated with transfusion requirements in orthotopic liver transplantation

BACKGROUND

Patients with end-stage chronic liver disease (CLD) and submitted to orthotopic liver transplantation (OLT) usually require blood transfusion during the procedure or in the post-operative period due to hemorrhage. Risk factors for transfusion need are not fully known. This study aimed to identify the factors associated with blood components requirements.

METHODS

In this retrospective study a total of 166 consecutive patients submitted to OLT with the piggyback technique, between 2001 and 2011, were evaluated for number of blood components transfused during surgical procedure and the four subsequent days (total of 5 days). We evaluated the association between the number of units transfused and clinical variables, such as: Child-Turcotte-Pugh (CTP) and MELD scores, hemoglobin concentration (Hb), INR, serum creatinine, bilirubin and albumin concentrations, and total, hypothermic and normothermic time of graft ischemia.

RESULTS

152 (91.6%) Patients were transfused (median of 24 units of blood components). Risk factors for higher blood transfusion requirements were CTP, INR, Hb and total time of graft ischemia. The group with CTP-A score received less blood components than CTP-B/C (11.5 vs 27; P=0.002). The group with Hb<10 required a higher number of blood units (34.5 vs 23; P=0.003). The group with INR<1.5 received less blood units (20.5 vs 31; P=0.012). The group transplanted with a graft exposed to less than the median of 555 min of ischemia received less transfusion (21 vs 27; P=0.03). MELD score and the other factors were not associated with blood requirements.

CONCLUSION

These results demonstrate that CTP, but not MELD score, hemoglobin concentration, INR, and total time of graft ischemia are preoperative variables associated with blood requirements during OLT and in the subsequent days.

Postoperative kidney injury does not decrease survival after liver transplantation

PURPOSE

To explore the effect of acute kidney injury (AKI) on long-term survival after conventional orthotopic liver transplantation (OLT) without venovenous bypass (VVB).

METHODS

A retrospective cohort study was carried out on 153 patients with end-stage liver diseases transplanted by the Department of General Surgery and Liver Transplantation of the University of Pernambuco, from August, 1999 to December, 2009. The Kaplan-Meier survival estimates and log-rank test were applied to explore the association between AKI and long-term patient survival, and multivariate analyses were applied to control the effect of other variables.

RESULTS

Over the 12.8-year follow-up, 58.8% patients were alive with a median follow-up of 4.5-year. Patient 1-, 2-, 3- and 5-year survival were 74.5%, 70.6%, 67.9% and 60.1%; respectively. Early postoperative mortality was poorer amongst patients who developed AKI (5.4% vs. 20%, p=0.010), but long-term 5-year survival did not significantly differed between groups (51.4% vs. 65.3%; p=0.077). After multivariate analyses, AKI was not significantly related to long-term survival and only the intraoperative transfusion of red blood cells was significantly related to this outcome (non-adjusted Exp[b]=1.072; p=0.045).

CONCLUSION

The occurrence of postoperative acute kidney injury did not independently decrease patient survival after orthotopic liver transplantation without venovenous bypass in this data from northeast Brazil.

Evaluation of the right ventricular ejection fraction during classic orthotopic liver transplantation without venovenous bypass

BACKGROUND

Right ventricular (RV) function is sensitive to changes in cardiac loading conditions, and RV dysfunction may contribute to hemodynamic instability during orthotopic liver transplantation (OLT). Thus, we evaluated RV function and its role in hemodynamic instability during classic OLT without venovenous bypass (VVB).

METHODS

Thirty patients undergoing classic OLT without VVB were studied. Right ventricular ejection fraction (RVEF) was measured using a modified pulmonary artery catheter. Hemodynamic data were recorded at pre-determined time points: T0, baseline; T1-T3: 5, 15, and 30 min after clamping; T4-T7: 5, 15, 30, and 120 min after reperfusion; T8 and T9: 24 and 48 h after surgery.

RESULTS

The baseline RVEF was lower than normal value. RVEF decreased significantly from T1 to T4 and returned to baseline beginning at T5. At 24 and 48 h after surgery, RVEF was higher than baseline value. RVEF was correlated with stroke volume index and post-reperfusion syndrome during OLT. Compared to the low MELDs group, RVEF in the high MELDs group was lower at T1, T2, and T4.

CONCLUSIONS

Right ventricular function was compromised during the anhepatic and early reperfusion stages in patients undergoing classic OLT without VVB, particularly in the high MELD score patients. Close monitoring of RV function in these patients should be considered.

Anesthesia for Liver Transplantation

Orthotopic liver transplantation is the only definitive treatment for end-stage liver disease. More than 6000 procedures are performed in the United States annually with excellent survival rates. The shortage of donor organs leads to continued interest in techniques to enlarge the potential donor pool. Patients presenting for liver transplant suffer from important cardiovascular, respiratory, renal, neurological, and gastroenterological comorbidity. In the Western world, liver failure is increasingly caused by steatohepatitis, and transplant candidates are thus becoming older and more comorbid. The role of the transplant anesthesiologist is highly important in the preoperative assessment, intraoperative management, and postoperative care of these complex and sick patients. Appropriate investigation and management of comorbidities such as coronary artery disease and portopulmonary hypertension is controversial and differs between programs. The transplant procedure is a major surgery, and although massive transfusion is no longer commonplace, there is potential for significant hemodynamic instability, coagulopathy, and metabolic disturbance. Liver transplant surgery can be divided into the preanhepatic phase, the anhepatic phase, and the reperfusion phase, with important anesthetic considerations at each point.  An understanding of the surgical techniques used for vascular exclusion of the liver and the role of venovenous bypass is crucial for the anesthesiologist. Recent trends in perioperative care include the use of antifibrinolytic drugs and point-of-care coagulation tests, intraoperative renal replacement therapy, and “fast-track” extubation and postoperative care. Care of patients with fulminant hepatic failure or those receiving split-liver grafts requires special consideration.

MRI-monitored intra-shunt local agent delivery of motexafin gadolinium: towards improving long-term patency of TIPS

Background

Transjugular intrahepatic portosystemic shunt (TIPS) has become an important and effective interventional procedure in treatment of the complications related to portal hypertension. Although the primary patency of TIPS has been greatly improved due to the clinical application of cover stent-grafts, the long-term patency is still suboptimal. This study was to investigate the feasibility of using magnetic resonance imaging (MRI)-monitored intra-shunt local agent delivery of motexafin gadolinium (MGd) into shunt-vein walls of TIPS. This new technique aimed to ultimately inhibit shuntstenosis of TIPS.

Methodology

Human umbilical vein smooth muscle cells (SMCs) were incubated with various concentrations of MGd, and then examed by confocal microscopy and T1-map MRI. In addition, the proliferation of MGd-treated cells was evaluated. For in vivo validation, seventeen pigs underwent TIPS. Before placement of the stent, an MGd/trypan-blue mixture was locally delivered, via a microporous balloon, into eleven shunt-hepatic vein walls under dynamic MRI monitoring, while trypan-blue only was locally delivered into six shunt-hepatic vein walls as serve as controls. T1-weighted MRI of the shunt-vein walls was achieved before- and at different time points after agent injections. Contrast-to-noise ratio (CNR) of the shunt-vein wall at each time-point was measured. Shunts were harvested for subsequent histology confirmation.

Principal Findings

In vitro studies confirmed the capability of SMCs in uptaking MGds in a concentration-dependent fashion, and demonstrated the suppression of cell proliferation by MGds as well. Dynamic MRI displayed MGd/blue penetration into the shunt-vein walls, showing significantly higher CNR of shunt-vein walls on post-delivery images than on pre-delivery images (49.5±9.4 vs 11.2±1.6, P<0.01), which was confirmed by histology.

Conclusion

Results of this study indicate that MRI-monitored intra-shunt local MGd delivery is feasible and MGd functions as a potential therapeutic agent to inhibit the proliferation of SMCs, which may open alternative avenues to improve the long-term patency of TIPS.

Non-cancerous prognostic factors of hepatocellular carcinoma after liver transplantation

PURPOSE

To explore non-cancerous factors that may be related with medium-term survival (24 months) after liver transplantation (LT) in this data from northeast Brazil.

METHODS

A cross-sectional study was carried out in patients who underwent deceased-donor orthotopic LT because hepatocellular carcinoma (HCC) at the University of Pernambuco, Brazil. Non-cancerous factors (i.e.: donor-, receptor-, surgery- and center-related variables) were explored as prognostic factors of medium-term survival using univariate and multivariate approachs.

RESULTS

Sixty-one patients were included for analysis. Their three, six, 12 and 24-month overall cumulative survivals were 88.5%, 80.3%, 73.8% and 65.6%, respectively. Our univariate analysis identified red blood cell transfusion (Exp[b]=1.26; p<0.01) and hepato-venous reconstruction technique (84.6% vs. 51.4%, p<0.01; respectively for piggyback and conventional approaches) as significantly related to post-LT survival. The multivariate analysis confirmed the hepato-venous reconstruction technique was an independent prognostic factor.

CONCLUSION

The piggyback technique was related to improved medium-term survival of hepatocellular carcinoma patients after liver transplantation in this northeast Brazilian sample.

Liver transplantation with preservation of the inferior vena cava: lessons learned through 2,000 cases

BACKGROUND

We aim to demonstrate the utility and efficacy of the "piggyback technique" (PBT); liver transplant (LT) with caval preservation.

STUDY DESIGN

Adult LTs were performed with intent to use the PBT except in cases of juxtacaval malignancy or technical difficulty. Hepatic venous outflow was established between the donor suprahepatic cava and the joined ostia of all recipient suprahepatic veins. Technical variants with the donor cava and recipient retrohepatic cava were used as needed. The experience was divided into 2 eras: E1 (1994-2002), E2 (2002-2010).

RESULTS

We completed 945 of 1080 LTs in E1 (87.5%) and 851 of 920 LTs in E2 (92.5%) using the PBT. Thirty day mortality was 4.6% in E1, 3% in E2 (p = 0.02) with 2 intra-operative deaths in E1. One, 3, 5 year patient survival was 83.7, 75.6, 69.3% in E1 vs. 86, 78.4, 73.8% in E2 (p = 0.057). Graft survival was 77.7, 69, 62.3% in E1 vs. 84, 76.2, 71.2% in E2 (p < 0.0001). Median operative time and hospital length of stay improved in E2 (p < 0.0001, 0.0001). Outflow variants were used more frequently in E2 (11.3% vs. 6.1%). Nine patients (0.5%) developed outflow obstruction, 6 in E1, and 3 in E2. Twice, it was recognized and corrected intraoperatively. Seven patients presented with refractory ascites. Six were successfully treated (4 balloon dilatation, 2 surgical revision), one patient died after attempted dilatation.

CONCLUSIONS

The PBT can be used as the preferred technique in adult LT. With experience, the technique was used more frequently, with more variants, with improved outcomes. Outflow obstruction was a rare complication.