Piggy-back versus conventional technique in liver transplantation: report of a randomized trial

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Comparison of Three Inferior Vena Cava Reconstruction Techniques in Adult Orthotopic Liver Transplantation: Result From King Chulalongkorn Memorial Hospital, Thailand

BACKGROUND

In orthotopic liver transplantation (OLT), 3 caval reconstruction techniques are being performed worldwide. These are conventional, piggyback technique, and side-to-side cavocaval anastomosis (CCA). Each has its own advantages and drawbacks. Herein we report the result from our hospital comparing the 3 techniques.

METHODS

We retrospectively reviewed the detail of OLT performed from January 2008 to March 2020. Data being collected included type of caval reconstruction, blood loss, operative time, ischemic time, length of stay in the intensive care unit (ICU) and total hospital stay, and several postoperative complications.

RESULTS

In the given period, 11 conventional, 90 piggyback, and 113 CCA caval reconstruction were done. There were no statistically significant differences in blood loss, operative time, cold ischemic time, and length of ICU and hospital stay. The CCA group had the lowest warm ischemic time (40 minutes) followed by the piggyback technique (43 minutes) and the conventional technique (47 minutes; P < .001). Regarding postoperative complications, there were no statistically significant differences in rate of primary nonfunction, early allograft dysfunction, hepatic artery/portal vein/biliary complication, or rate of acute kidney injury. The hepatic venous outflow complication rate was indifferent between 3 groups.

CONCLUSIONS

The present study showed no difference in outflow obstruction rate among the 3 techniques. The choice for reconstruction should rely on the preference of each institute and the suitability of each patient. The CCA technique may provide the lowest warm ischemic time.

Sonography of liver transplantation

Orthotopic liver transplant (OLT) is established as the definitive treatment of choice for end stage liver disease. Over the years, refined surgical techniques as well as advancements in organ preservation and immunosuppressive regimens have improved graft and patient survival rates. Imaging has also contributed to improved graft and patient survival. Ultrasound is the initial investigation of choice for evaluation of post-transplant anatomy and for identifying early complications. A thorough knowledge of surgical techniques and normal post-operative appearance of the OLT is needed to accurately identify and characterize graft complications. The objective of this article is to review the sonographic findings of normal liver transplant as well as post-operative complications. Indications and contraindications for OLT as well as different surgical techniques will also be briefly reviewed.

Portal vein reconstruction using side-to-side unification technique for infant-to-infant deceased donor whole liver transplantation

Backgrounds/Aims

Infant-to-infant whole liver transplantation (I2I-WLT) has been rarely performed in Korea. We analyze clinical sequences of our 7 cases of I2I-WLT and present evolution of surgical techniques to prevent PV stenosis.

Methods

A total of 7 cases of I2I-WLT were performed at our institution during last 13 years, which represented 0.1% of our LT volume. Patient perioperative profiles and clinical sequences were analyzed with focusing on portal vein (PV) complications.

Results

Donor ages were 6-17 months and graft weights were 140-525 g. Recipient ages were 7-16 months and body weights were 6-10.1 kg and Primary diagnoses were biliary atresia in 6 and progressive familial intrahepatic cholestasis in 1. The first case underwent PV stenting 2 months after I2I-WLT, and underwent retransplantation 6 years later. The second case underwent intraoperative PV stenting, but died 32 days later. The third case underwent repeated PV dilatation. The fourth, fifth and seventh cases experienced no surgical complications, and PV reconstruction was performed using a side-to-side unification venoplasty technique. The sixth case had poor development of the PV system, so customized PV venoplasty was performed, but PV occlusion requiring PV stenting occurred. Early retransplantation was performed, but scanty PV flow was detected despite no obvious PV stenosis, resulting in graft failure. Serious PV complications developed in 4, but none experienced after adoption of side-to-side unification venoplasty.

Conclusions

As PV size in infant donors and recipients is very small, PV reconstruction in I2I-WLT requires specialized surgical techniques of side-to-side unification venoplasty.

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.

Outcome after ex situ or ante situm liver resection with hypothermic perfusion and auto-transplantation: A single-centre experience in adult and paediatric patients

BACKGROUND

Evolving surgical technology and medical treatment have led to an expansion of indications to enable resection of large hepatic tumours with involvement of other abdominal structures.

METHODS

Twelve extended liver and abdominal resections, either ex situ with auto-transplantation of the liver remnant or ante situm with veno-venous bypass (VVBP) were performed between 2016 and 2018. We describe our preoperative assessment, compare surgical strategies and assess outcomes.

RESULTS

The median age of the 10 adult patients was 50.5 years with a majority suffering from sarcoma-like tumours. The two paediatric patients were 3 and 8 years of age, both with hepatoblastoma. Two patients underwent ex situ resections with auto-transplantation of the liver remnant, and nine patients had ante situm tumour removal with the use of VVBP in four. All patients achieved a good immediate liver function. Local infection and acute kidney injury were found in two patients. One patient underwent biliary reconstruction for bile leak. Tumour recurrence was seen in seven patients (58.3%), with four lung metastases. Five patients died from tumour recurrence (41.7%) during the follow-up.

CONCLUSION

Extreme liver resections should be performed in experienced centres, where surgical subspecialties are available with access to cardiovascular support. Additionally, experience in split and living-donor liver transplantation is beneficial.

Normal and transitory ultrasonography findings in the immediate postoperative period after liver transplantation

OBJECTIVE

Liver transplantation is one of the treatments for patients with advanced stage chronic liver disease and for selected patients with hepatic tumors. Ultrasonography is the first-choice imaging technique to evaluate liver transplants. This article reviews the surgical technique, anatomy, and normal findings on ultrasonography in the immediate postoperative period in patients who have undergone liver transplantation, which will be used as a reference in follow-up studies.

CONCLUSION

Early vascular (arterial and portal) complications can represent a threat for the graft or the patient. During the period after liver transplantation, the patient is recovering from surgery and the transplanted organ is adapting to its new environment. In this period, ultrasonography can show alterations in the parenchyma or Doppler findings that would be considered abnormal in other situations; these findings are usually transitory. Knowing how to interpret them is key to detecting or ruling out complications.

Perioperative hemostatic management in the cirrhotic patient: a position paper on behalf of the Liver Intensive Care Group of Europe (LICAGE)

Recent data demonstrated that amongst patients undergoing elective surgery the prevalence of cirrhosis is 0.8% equating to approximately 25 million cirrhotic patients undergoing surgery each year worldwide. Overall, the presence of cirrhosis is independently associated with 47% increased risk of postoperative complications and over two and a half-increased risk of in-hospital mortality in patients undergoing elective surgery. In particular, perioperative patients with chronic liver disease have long been assumed to have a major bleeding risk on the basis of abnormal results for standard tests of hemostasis. However, recent evidence outlined significant changes to traditional knowledge and beliefs and, nowadays, with more sophisticated laboratory tests, it has been shown that patients with chronic liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. The aim of this paper endorsed by the Liver Intensive Care Group of Europe was to provide an up-to-date overview of coagulation management in perioperative patients with chronic liver disease focusing on patient blood management, monitoring of hemostasis, and current role of hemostatic agents.

Technical Aspects of Orthotopic Liver Transplantation-a Survey-Based Study Within the Eurotransplant, Swisstransplant, Scandiatransplant, and British Transplantation Society Networks

BACKGROUND

Orthotopic liver transplantation (OLT) has emerged as the mainstay of treatment for end-stage liver disease. However, technical aspects of OLT are still subject of ongoing debate and are widely based on personal experience and local institutional protocols.

METHODS

An international online survey was sent out to all liver transplant centers (n = 52) within the Eurotransplant, Swisstransplant, Scandiatransplant, and British Transplant Society networks. The survey sought information on center-specific OLT caseload, vascular and biliary reconstruction, graft reperfusion, intraoperative control of hemodynamics, and drain policies.

RESULTS

Forty-two centers gave a valid response (81%). Out of these, 50% reported piggy-back and 40.5% total caval replacement as their standard technique. While 48% of all centers generally do not apply veno-venous bypass (vvBP) or temporary portocaval shunt (PCS) during OLT, vvBP/PCS are routinely used in six centers (14%). Portal vein first reperfusion is used in 64%, followed by simultaneous (17%), and retrograde reperfusion (12%). End-to-end duct-to-duct anastomosis without biliary drain (67%) is the most frequently performed method of biliary reconstruction. No significant associations were found between the center caseload and the surgical approach used. The predominant part of the centers (88%) stated that techniques of OLT are not evidence-based and 98% would participate in multicenter clinical trials on these topics.

CONCLUSION

Technical aspects of OLT vary widely among European centers. The extent to which center-specific variation of techniques affect transplant outcomes in Europe should be elucidated further in prospective multicenter trials.

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.

Imaging of liver transplantation

Liver transplantation (LT) is the treatment of choice for end-stage chronic liver disease, fulminant liver failure and early stage hepatocellular carcinoma. As discussed in this review, state-of-the-art imaging modalities including ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) play a pivotal role in the selection of patients and donors, as well as in early detection of those complications at risk of impairing graft function and/or survival. We also illustrate main imaging findings related to the wide spectrum of clinical problems raised by LT.

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.

Acute kidney injury after liver transplantation: Recent insights and future perspectives

Acute kidney injury (AKI) is a common postoperative complication after liver transplantation (LT). The occurrence of postoperative AKI after LT (Post-LT AKI) is associated with inferior patient and graft outcomes. Post-LT AKI is multifactorial in origin and has been related to the severity of liver disease, pre-LT renal dysfunction, graft quality, perioperative events and toxicity of immunosuppressive therapy. Furthermore it is thought that hepatic ischaemia reperfusion injury might be a driving force in the aetiology of post-LT AKI. Novel biomarkers for AKI are emerging and can be useful for early identification and characterization of AKI. There is a clear need for strategies aimed at preventing or treating post-LT AKI. Several pharmacological and non-pharmacological interventions have been studied, but so far failed to show any benefit in the prevention of post-LT AKI. Further studies are needed to develop and evaluate new interventions aimed at preventing post-LT AKI and improve patient outcomes.

Imaging follow-up after liver transplantation

Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.

Imaging panorama in postoperative complications after liver transplantation

The liver is the second most-often transplanted solid organ after the kidney, so it is clear that liver disease is a common and serious problem around the globe. With the advancements in surgical, oncological and imaging techniques, orthotopic liver transplantation has become the first-line treatment for many patients with end-stage liver disease. Ultrasound, and Doppler are the most economical and cost-effective imaging modalities for evaluating postoperative fluid collections and vascular complications. Computed tomography (CT) is used to confirm the findings of ultrasound and look for pulmonary complications. Magnetic resonance imaging (MRI) is used for the diagnosis of biliary complications, bile leaks and neurological complications. This article illustrates the imaging options for diagnosing the various complications that can be encountered in the postoperative period after liver transplantation.

Hepatic venous outflow obstruction in piggyback liver transplantation: single centre experience

BACKGROUND

Hepatic venous outflow obstruction (HVOO) is a rare but serious complication in liver transplantation (LT).

METHODS

We conducted a retrospective analysis of HVOO with venography and gradient measurement in consecutive LT from a single centre.

RESULTS

Five hundred and six LTs were performed in 486 patients with a median age of 49 years (range 3 months to 71 years). Nineteen (3.8%) cases of HVOO were identified. Diagnosis was confirmed at a median of 26 days post-LT (1-2312). The incidence fell from 5.5% in the first 253 LT, to 2.0% in the second 253 (P = 0.03). Seventeen were due to narrowing at the anastomosis and two cases were due to thrombosis. In adult patients, reconstruction of the supra-hepatic donor inferior vena cava (IVC) onto two veins versus modified 2-3 hepatic veins did not alter the likelihood of HVOO. 17/19 cases were managed successfully by stenting or venoplasty. Two paediatric patients with early onset HVOO had attempted surgical thrombectomy, one was successful and the other required retransplantation.

CONCLUSION

The incidence of HVOO appears to fall with increasing experience and does not appear to be related to the number of veins the donor IVC is anastomosed to in adult recipients.

Prospective Randomized Trial Comparing Hepatic Venous Outflow and Renal Function after Conventional versus Piggyback Liver Transplantation

Background

This randomized prospective clinical trial compared the hepatic venous outflow drainage and renal function after conventional with venovenous bypass (n = 15) or piggyback (n = 17) liver transplantation.

Methods

Free hepatic vein pressure (FHVP) and central venous pressure (CVP) measurements were performed after graft reperfusion. Postoperative serum creatinine (Cr) was measured daily on the first week and on the 14^th, 21^st and 28^th postoperative days (PO). The prevalence of acute renal failure (ARF) up to the 28th PO was analyzed by RIFLE-AKIN criteria. A Generalized Estimating Equation (GEE) approach was used for comparison of longitudinal measurements of renal function.

Results

FHVP-CVP gradient > 3 mm Hg was observed in 26.7% (4/15) of the patients in the conventional group and in 17.6% (3/17) in the piggyback group (p = 0.68). Median FHVP-CVP gradient was 2 mm Hg (0–8 mmHg) vs. 3 mm Hg (0–7 mm Hg) in conventional and piggyback groups, respectively (p = 0.73). There is no statistically significant difference between the conventional (1/15) and the piggyback (2/17) groups regarding massive ascites development (p = 1.00). GEE estimated marginal mean for Cr was significantly higher in conventional than in piggyback group (2.14 ± 0.26 vs. 1.47 ± 0.15 mg/dL; p = 0.02). The conventional method presented a higher prevalence of severe ARF during the first 28 PO days (OR = 3.207; 95% CI, 1.010 to 10.179; p = 0.048).

Conclusion

Patients submitted to liver transplantation using conventional or piggyback methods present similar results regarding venous outflow drainage of the graft. Conventional with venovenous bypass technique significantly increases the harm of postoperative renal dysfunction.

Trial Registration

ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT01707810

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.

Hepatic transplantation: postoperative complications

Advances in surgical techniques and immunosuppression have made orthotopic liver transplantation a first-line treatment for many patients with end-stage liver disease. The early detection and treatment of postoperative complications has contributed significantly to improved graft and patient survival with imaging playing a critical role in detection. Complications that can lead to graft failure or patient mortality include vascular abnormalities, biliary abnormalities, allograft rejection, and recurrent or post-transplant malignancy. Vascular abnormalities include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava, as well as hepatic artery pseudoaneurysm, arteriovenous fistula, and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not used to diagnose allograft rejection, it plays an important role in identifying complications that can mimic rejection. Ultrasound is routinely performed as the initial imaging modality for the detection and follow-up of both early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are used to characterize biliary complications and computed tomography is used to confirm abnormal findings on ultrasound or for the evaluation of postoperative collections. The purpose of this article is to describe and illustrate the imaging appearances and management of complications associated with liver transplantation.

Different cava reconstruction techniques in liver transplantation: piggyback versus cava resection

BACKGROUND

Originally, cava reconstruction (CR) in liver transplantation meant complete resection and reinsertion of the donor cava. Alternatively, preservation of the recipients inferior vena cava (IVC) with side-to-side anastomosis (known as "piggyback") can be performed. Here, partial clamping maintains blood flow of the IVC, which may improve cardiovascular stability, reduce blood loss and stabilize kidney function. The aim of this study was to compare both techniques with particular focus on kidney function.

METHODS

A series of 414 patients who had had adult liver transplantations (2006-2009) were included. Among them, 176 (42.5%) patients had piggyback and 238 had classical CR operation, 112 (27.1%) of the patients underwent CR accompanied with veno-venous bypass (CR-B) and 126 (30.4%) without a bypass. The choice of either technique was based on the surgeons' individual preference. Kidney function [serum creatinine, calculated glomerular filtration rate (GFR), RIFLE stages] was assessed over 14 days.

RESULTS

Lab-MELD scores were significantly higher in CR-B (22.5+/-11.0) than in CR (17.3+/-9.0) and piggyback (18.8+/-10.0) (P=0.008). Unexpectedly, the incidences of arterial stenoses (P=0.045) and biliary leaks (P=0.042) were significantly increased in piggyback. Preoperative serum creatinine levels were the highest in CR-B [1.45+/-1.17 vs 1.25+/-0.85 (piggyback) and 1.13+/-0.60 mg/dL (CR); P=0.033]. Although a worsening of postoperative kidney function was observed among all groups, this was most pronounced in CR-B [creatinine day 14: 1.67+/-1.40 vs 1.35+/-0.96 (piggyback) and 1.45+/-1.03 mg/dL (CR); P=0.102]. Accordingly, the proportion of patients displaying RIFLE stages ≥2 was the highest in CR/CR-B (26%/19%) when compared to piggyback (18%).

CONCLUSIONS

Piggyback revealed a shorter warm ischemic time, a reduced blood loss, and a decreased risk of acute kidney failure. Thus, piggyback is a useful technique, which should be applied in standard procedures. When piggyback is unfeasible, cava replacement, which displayed a lower incidence of vascular and biliary complications in our study, remains as a safe alternative.

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.

Endovascular treatment with primary stenting of inferior cava vein torsion following orthotopic liver transplantation with modified piggyback technique

PURPOSE

This study was undertaken to evaluate primary stenting in patients with inferior vena cava torsion after orthotopic liver transplantation performed with modified piggyback technique.

MATERIALS AND METHODS

From November 2003 to October 2010, six patients developed clinical, laboratory and imaging findings suggestive of caval stenosis, after a mean period of 21 days from an orthotopic liver transplantation performed with modified piggyback technique. Vena cavography showed stenosis due to torsion of the inferior vena cava at the anastomoses and a significant caval venous pressure gradient. All patients were treated with primary stenting followed by in-stent angioplasty in three cases.

RESULTS

In all patients, the stents were successfully positioned at the caval anastomosis and the venous gradient pressure fell from a mean value of 10 to 2 mmHg. Signs and symptoms resolved in all six patients. One patient died 3 months after stent placement due to biliary complications. No evidence of recurrence or complications was noted during the follow-up (mean 49 months).

CONCLUSIONS

Primary stenting of inferior vena cava stenosis due to torsion of the anastomoses in patients receiving orthotopic liver transplantation with modified piggyback technique is a safe, effective and durable treatment.

Preoperative hepatobiliary imaging: what does the radiologist need to know?

Accurate preoperative reporting is essential in guiding the surgeon in deciding when and how to operate safely and effectively. Critically, this relies on an understanding of the operative issues faced by the surgeon, which is not always appreciated by the radiologist. This paper therefore aims to address this, first focusing on relevant anatomical variants, and then issues specific to laparoscopic cholecystectomy, hepatic transplantation, and finally hepatic resection (including cholangiocarcinoma resection). Throughout the paper, there is an emphasis on associated surgical techniques to add context to the discussion.

"Passing loop" technique: a new modification of the piggyback technique tailored to voluminous liver grafts--case report

BACKGROUND

The modified piggyback technique with side-to-side cavocavostomy decreases the risk of outflow obstruction compared with the standard piggyback method. However, this modification is not ideal for recipients who receive a graft that is voluminous or bears an enlarged caudate lobe.

METHODS

We modified the inferior vena cava (IVC) preservation technique against deleterious complications of compression by using a passing loop.

CASE PRESENTATION

A 49-year-old woman, who underwent orthotopic liver transplantation for hepatic failure, was allocated a large-size liver. In anticipation of serious caval compression due to the voluminous grafts, we kept the suprahepatic or infrahepatic donor caval cuffs open for an anastomosis. The first anastomosis was performed between suprahepatic donor IVC cuff and recipient middle-left hepatic vein common channel; the second anastomosis was a terminolateral cavocavostomy between infrahepatic donor IVC cuff and the anterior wall of the recipient's IVC.

DISCUSSION

When the liver circulation was restored, the donor retrohepatic vena cava served as a passing loop for both hepatic venous outflow and infra-diaphragmatic venous return to bypass possible IVC compression. Our technique may solve a dilemna for patients receiving voluminous liver grafts.

Orthotopic liver transplantation without venovenous bypass: 125 cases from a single center

AIM

This study analyzed a 10-year single-center experience in orthotopic liver transplantation (OLT) without venovenous bypass (VVB).

METHODS

We retrospectively analysed a nonrandomized series (1999-2008) of 125 adult OLT patients without VVB.

RESULTS

The main causes of liver failure were viral hepatitis (n = 39), alcoholic liver disease (n = 22), and liver cancer (n = 17). One-year survival was 76.4%. The most common postoperative complications were bile duct stenosis (n = 12), postoperative bleeding (n = 8), hepatic artery thrombosis (n = 7), and primary liver failure (n = 6). Twelve patients required hemodialysis and four underwent retransplantations of the liver. Fourteen patients died before postoperative day 30(th). Univariate analysis showed significant differences between patients who did and did not survive 30 days among donor death diagnoses (P = .05), red blood cell units transfused (P = .03), aspartate aminotranferase on the first postoperative day (P = .002), ABO type (P = .04), time of orotracheal intubation (P = .001), hemodialysis (P = .001), and period of postoperative vasoactive drug use (P = .006). The total length of orotracheal tube intubation showed a significant independent association with mortality before 30 days (P < .001).

CONCLUSION

OLT without VVB can be safely performed even in severe cases of chronic liver failure.

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.

Coagulopathy management in liver transplantation

Risk of bleeding and transfusion in liver transplantation is determined by age, severity of liver disease, as well as hemoglobin and plasma fibrinogen values. During the hepatectomy and the anhepatic phase, the coagulopathy is related to a decrease in clotting factors caused by surgical bleeding, facilitated by the increased portal hypertension and esophageal-gastric venous distension. Corrections of hematologic disturbances by administration of large volumes of crystalloid, colloid, or blood products may worsen the coagulopathy. Also, impaired clearance of fibrinolytic enzymes released from damaged cells can lead to primary fibrinolysis. At time of graft reperfusion further deterioration may occur as characterized by global reduction among all coagulation factors, decreased plasminogen activator inhibitor factors, and simultaneous generation of tissue plasminogen activator. In situations with inherent risk of bleeding, hypofibrinogenemia must be corrected. Concern about unwanted events is a major limitation of preventive therapy. There is some evidence for the efficacy of antifibrinolytic drugs to reduce red blood cell requirements. A guide for antifibrinolytic therapy are clot firmness in trhomboelastometry or alternatively, diffuse bleeding associated to a fibrinogen value less than 1 g/L. Because thrombin generation is limited in severe thrombocytopenia, platelet administration is recommended when active bleeding coexists with a platelet count below 50,000/mm(3). When the administration of hemoderivates and antifibrinolytic drugs does not correct severe bleeding, consumption coagulopathy and secondary fibrinolysis should be suspected. Treatment of affected patients should be based upon correcting the underlying cause, mostly related to tissue hypoxia due to critical hypoperfusion.

Current concepts in pediatric liver transplantation

Liver transplantation is the definitive treatment for end-stage liver disease in both children and adults. Advances over the last 2 decades have resulted in excellent patient and graft survival rates in what were previously cases of fatal disorders. These developments have been due to innovations in surgical technique, increased surgical experience, refinements in immunosuppressive regimens, quality improvements in intraoperative anesthetic management, better understanding of the pathophysiology of the liver diseases, and better preoperative and postoperative care. Remarkably, the use of split-liver and living-related liver transplantation surgical techniques has helped mitigate the well-recognized national organ shortage. This review will discuss the major aspects of pediatric liver transplantation as it pertains to indication for transplantation, recipient selection and listing for orthotopic liver transplantation, pre-orthotopic liver transplantation care of children, optimal timing of orthotopic liver transplantation, surgical technical considerations, postoperative care and complications, and patient and graft survival outcomes.

Liver transplantatation- an overview

Liver transplantation is a therapeutic option of choice for acute and chronic end-stage liver disease. Indications, contraindications, and surgical procedures for the liver transplantation have become well established. In most part of the world, the main source of liver for transplantation remains the donation after brain death (DBD), but in view of increasing death on the waiting list due to shortage of brain dead organs other options such as split liver transplantation, living donor liver transplantation (LDLT), and donation after cardiac death (DCD) have been used. In the pretransplantation era, liver failure was nearly universally fatal, with mortality from fulminant hepatic failure of 80-90 %, and 1-year mortality in decompensated cirrhosis of more than 50 %. In contrast, liver transplantation patient survival is presently more than 85 % at 1 year and more than 70 % at 5 years, emphasizing the clinical benefit of liver transplantation for either acute or chronic liver failure.

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

INTRODUCTION

Orthotopic liver transplantation is a widely used procedure for the treatment of irreversible liver diseases for which there is no possibility of medical treatment. When this procedure is performed by the conventional technique, the retrohepatic vena cava is removed along with the native liver. The inferior vena cava (IVC) remains clamped until the revascularization of the graft, and in this period there is a reduction in the venous return, which may induce a fall by up to 50% in the cardiac output with hemodynamic instability and a fall in renal perfusion pressure. The use of a portal-femoral-axillary venovenous bypass system, in which the blood from the femoral and portal veins returns to the heart via the axillary vein propelled by a centrifugal pump, is intended to minimize the effects of the IVC clamping. In the piggyback (PB) technique, the native liver is removed and the IVC of the recipient is preserved and only partially clamped. We have employed both techniques without the use of venovenous bypass for 10 years. The objective of this study was to compare the results obtained from the use of the two techniques.

PATIENTS AND METHODS

A retrospective analysis was performed of 195 patients transplanted between 1999 and 2008: 125 by the conventional technique and 70, the PB technique. The intraoperative parameters were analyzed (surgical time, ischemia time, use of blood products, and diuresis), as well as intensive care support (duration of stay in intensive care unit and use of vasoactive drugs), period of intubation, length of hospital stay, renal function, graft function, postoperative complications, retransplantation, and patient survival.

RESULTS

The PB group showed a reduction in surgical time, warm ischemia time, the use of packed red blood cells concentrates, and fresh frozen plasma, as well as mortality at 30 days (P<.05). There were no differences in relation to cold ischemia time, intraoperative diuresis; length of stay and use of vasoactive drugs in the intensive care unit; the period of intubation; the duration of hospital stay; the renal function; the graft function; the need for reoperation; the incidence of sepsis, biliary complications, vascular complications; need for retransplantation; and 1-year mortality. The cumulative survival rate at 1 year was significantly better among the PB patients.

CONCLUSION

Orthotopic liver transplantation can be performed without venovenous bypass with good results, using either the conventional technique or the PB technique. Provided that there is no technical contraindication and a long ischemia period is not foreseen, the PB technique should be the technique of choice.

Does caval reconstruction technique affect early graft function after liver transplantation? A preliminary analysis

BACKGROUND

In the past decades, the inferior vena cava (IVC) reconstruction technique has undergone several evolutions, such as biopump, piggyback technique (PB), and laterolateral approach (LLPB). Several advantages are reported comparing the PB technique to biopump use. However, comparison between PB and LLPB has not been as well investigated. The aim of this study was to compare the results in terms of immediate graft function and intermediate graft survival among 3 subgroups characterized by distinct caval reconstruction techniques.

METHODS

We retrospectively analyzed a cohort of 200 consecutive adult patients who underwent liver transplantation from January 2001 to December 2009. The patients were stratified according to 3 caval reconstructive techniques: biopump (n=135), PB (n=32) and LLPB (n=33).

RESULTS

The LLPB group showed the shortest cold and warm ischemia times and the best immediate postoperative graft function. Survival analysis revealed LLPB patients to present the best 1-year graft survival rates: namely, 90.9% versus 75.0% and 74.1% among the PB and biopump groups, respectively (log-rank tests: LLPB vs biopump: P=.03; LLPB vs PB: P=.05). In our experience, LLPB showed the best graft survivals with an evident reduction in both cold and warm ischemia times. However, it is hard to obtain an irrefutable conclusion owing to the retrospective nature of this study, the small sample, and the different periods in which the groups were transplanted.

CONCLUSIONS

LLPB technique was a safe procedure that minimized the sequelal of ischemia-reperfusion damage. This technique yielded results superior to venovenous bypass. No definitive conclusions can to be obtained in this study comparing classic PB or LLPB.

Piggy-back graft for liver transplantation

BACKGROUND

Piggy-back method of transplantation, which involves preservation of the recipient retrohepatic inferior vena cava, has been suggested as an alternative to the conventional method of liver transplantation, where the recipient retrohepatic inferior vena cava is resected.

OBJECTIVES

To compare the benefits and harms of piggy-back technique versus conventional liver transplantation as well as of the different modifications of piggy-back technique during liver transplantation.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until June 2010 for identifying randomised trials using search strategies.

SELECTION CRITERIA

Only randomised clinical trials, irrespective of language, blinding, or publication status were considered for the review.

DATA COLLECTION AND ANALYSIS

Two authors (KSG and VP) independently identified trials and independently extracted data. We calculated the mean difference (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) using both the fixed-effect and the random-effects models with RevMan 5 based on intention-to-treat analysis for continuous outcomes. For binary outcomes, we used the Fisher's exact test since none of the comparisons of binary outcomes included more than one trial.

MAIN RESULTS

Two trials randomised in total 106 patients to piggy-back method (n = 53) versus conventional method with veno-venous bypass (n = 53). Both trials were at high risk of bias. There was no significant difference in post-operative mortality, primary graft non-function, vascular complications, renal failure, transfusion requirements, intensive therapy unit (ITU) stay, or hospital stay between the two groups. The warm ischaemic time was significantly shorter in the piggy-back method than the conventional method (MD -11.50 minutes; 95% CI -19.35 to -3.65; P < 0.01). The proportion of patients who developed chest complications were significantly higher in the the piggy-back method than the conventional method (75.8% versus 44.1%; P = 0.01).One trial randomised 80 patients to piggy-back with porto-caval bypass (n = 40) versus piggy-back without porto-caval bypass (n = 40). This trial was at high risk of bias. There was no significant difference in post-operative mortality, re-transplantation due to primary graft non-function, vascular complications, renal failure, or hospital stay between the two groups. Fewer patients required blood transfusion in the piggy-back with porto-caval bypass group (55%) than the piggy-back without porto-caval bypass group (75%) (P = 0.02). There was no significant difference in the mean amount of blood transfused between the groups (MD -1.00 unit; 95% CI -2.19 to 0.19; P = 0.10). The ITU stay was significantly shorter in the piggy-back with porto-caval bypass group (2.9 days) than the piggy-back without porto-caval bypass group (4.9 days; MD -2.00 days; 95% CI -3.82 to -0.18; P = 0.03).There were no trials comparing piggy-back method with conventional method without veno-venous bypass or different techniques of piggy-back method.

AUTHORS' CONCLUSIONS

There is currently no evidence to recommend or refute the use of piggy-back method of liver transplantation.

Comparison of surgical methods in liver transplantation: retrohepatic caval resection with venovenous bypass (VVB) versus piggyback (PB) with VVB versus PB without VVB

Use of piggyback technique (PB) and elimination of venovenous bypass (VVB) have been advocated in adult liver transplantation (LT). However, individual contribution of these two modifications on clinical outcomes has not been fully investigated. We performed a retrospective review of 426 LTs within a 3-year period, when three different surgical techniques were employed per the surgeons' preference: retrohepatic caval resection with VVB (RCR+VVB) in 104 patients, PB with VVB (PB+VVB) in 148, and PB without VVB (PB-Only) in 174. The primary outcomes were intraoperative blood transfusion and the patient and graft survivals. Demographic profiles were similar, except younger recipient age in RCR+VVB and fewer number of grafts with cold ischemic time over 16 h in PB-Only. PB-Only required lesser intraoperative red blood cells (P=0.006), fresh frozen plasma (P=0.005), and cell saver return (P=0.007); had less incidence of acute renal failure (P=0.001), better patient survival (P=0.039), and graft survival (P=0.003). The benefits of PB+VVB were only found in shortened total surgical time (P=0.0001) and warm ischemic time (P=0.0001), and less incidence of acute renal failure (P=0.001) than RCR+VVB. PB-Only method seemed to provide the best clinical outcome. The benefit of PB was not fully achieved when it was used with VVB.

An alternative surgical technique for caval preservation in liver transplantation

INTRODUCTION

The results of orthotopic liver transplantation in patients with end-stage liver disease continue to improve. Refinements in surgical techniques represent an important part of this improvement.

MATERIALS AND METHODS

With the advent of split-liver and living-donor liver transplantation, inferior vena cava (IVC) preservation transitioned from being a potential option to being mandatory for many cases. Preserving the IVC can be a demanding technical maneuver in many liver transplants and several different approaches have been developed. When utilizing IVC preservation, there are several options for implantation of the graft. The piggyback technique, when feasible, is considered safe and provides hemodynamic stability for the recipient.

RESULTS AND DISCUSSION

In some cases it may be difficult to perform the piggyback technique if intense inflammatory adhesions and severe significant collateral circulation exist between the IVC and the posterior segments of the liver. In these cases, the retro-hepatic dissection can be carried out with a different approach: the infrahepatic vena cava and the confluence of the three hepatic veins can be cross-clamped en-bloc without dissection.

CONCLUSION

This technique broadens the transplant surgeons' armamentarium and can be used in the setting of a very difficult retro-hepatic dissection. It is safe, and allows a shorter anhepatic phase with caval preservation.

Four hundred and twenty-three consecutive adults piggy-back liver transplantations with the three suprahepatic veins: was the portal systemic shunt required?

BACKGROUND AND AIMS

The aim of this study is to analyze a single-center experience in orthotopic liver transplantation with the piggy-back technique (PB) realized with a cuff of three veins without temporary portacaval shunt. Outcome parameters were graft and patient survival and the surgical complications.

METHODS

The records of 423 liver transplantation in 396 adult recipients were reviewed. PB was performed in all cases also in patients with transjugular intrahepatic portosystemic shunts and redo transplants without temporary portacaval shunt. No hemodynamic instability was observed during venous reconstruction.

RESULTS

Operation time, cold ischemia time and anhepatic phase were, respectively, 316, 606 and 82 min, respectively. The mean intraoperative transfusion of packed red blood cells was 3.2 (range 1-48). Surgical complications were observed in 25% of the orthotopic liver transplantation and 2% of these was related to caval anastomosis. No case of caval thrombosis was observed; a stenosis was noted in seven patients, always treated with an endovascular approach. A postoperative ascites was observed in seven cases. Retransplantation was required in 6.3% patients. Overall in-hospital mortality was 5.3%, but no patient died through technical problems or complications related to PB procedure. One-, 3- and 5-year grafts and patients were 94%, 83% and 75%, and 92%, 86% and 79%, respectively.

CONCLUSION

This experience indicates that our approach is feasible with a low specific risk and can be performed without portacaval shunt, with minimal outflow venous complications.

Liver donor's age and recipient's serum creatinine predict blood component use during liver transplantation

BACKGROUND

Excessive use of blood components during liver transplantation should be avoided because it has been associated with poor outcomes and it may stress blood bank resources.

STUDY DESIGN AND METHODS

To determine preoperative predictors of excessive transfusion requirements in patients undergoing liver transplantation, the clinical records of 126 consecutive adult patients undergoing primary liver transplantation were retrospectively reviewed. Outcome variables included number of red blood cells (RBCs), plasma, and plateletpheresis components intraoperatively transfused. Univariate analyses of the following predictor variables were performed: recipient age, sex, ethnicity, height/weight, Model for End Stage Liver Disease score, year of transplant, previous abdominal surgery, hepatoma, wait-list time, standard recipient laboratory values obtained immediately before transplantation, cold ischemia time, donor age, sex, and height/weight. Multivariate analysis using logistic regression was used to build a model that best predicted how many blood components should be available before transplant.

RESULTS

Donor age of more than 50 years old (odds ratio [OR], 2.8 95% confidence interval [CI], 1.3-6.0), and recipient serum creatinine (SCr) level of more than 1.3 mg/dL (OR, 3.8 95% CI, 1.6-8.9) were the only variables found to be predictive of RBC use in multivariate analysis. This model accurately predicted the use of more than 10 units of RBCs 79% of cases. Having both adverse factors present resulted in using more than one box in 80% of cases as compared to 44% of cases where only one or no adverse factor was present (p = 0.002). Further analyses showed a direct correlation between the number of RBCs transfused and plasma (r = 0.93) and plateletpheresis components (r = 0.74) transfused. [Corrections added after online publication 22-Jul-2009: OR updated from 3.8 to 2.8; CI from 1.6-8.9 to 1.3-6.0; OR from 2.8-3.8.]

CONCLUSION

Liver donor's age and recipient's SCr are important in preoperatively predicting blood use during liver transplantation.

A single-center experience of 500 liver transplants using the modified piggyback technique by Belghiti

Over the past 4 decades, the surgical techniques of liver transplantation (LTx) have permanently evolved and been modified. Among these, the modified piggyback (MPB) technique by Belghiti offers specific advantages. The objective of this study was to present our single-center experience with the MPB technique in 500 cases. Recipients' perioperative data were prospectively collected and evaluated. Postoperative and specific complications, stay in the intensive and intermediate care unit, and the mortality rate with cause of death were analyzed. Most recipients were classified as Child C (49.1%). For the patients who underwent LTx for the first time, alcoholic (23.9%) and viral (22.2%) cirrhosis and hepatocellular carcinoma (15.1%) were the prevalent indications. The overall median warm ischemia time, anastomosis duration, and operative time were 45, 108, and 320 minutes, respectively. The median intraoperative blood loss was 1500 mL. A venovenous bypass was never needed to maintain hemodynamic stability. Only in a few cases was temporary inferior vena cava clamping necessary. Most prominent surgical complications were hemorrhage, hematoma, and wound dehiscence. Renal failure occurred in 6.2% of patients. The overall median stay in the intensive and intermediate care unit was 14 days. The mortality rates within 30 and 90 days were 6.3% and 13.3%, respectively. No technique-related death occurred. The MPB technique by Belghiti is a feasible and simple LTx technique. The caval flow is preserved during the anhepatic phase, and this minimizes the need for venovenous bypass or portocaval shunt. This technique requires only 1 caval anastomosis, which is easy to perform with a short anhepatic phase. To minimize the risk of outflow obstruction, attention should be paid by doing a wide cavocavostomy cranially to the donor inferior vena cava in a door-lock manner. This technique can be applied in almost all patients undergoing LTx for the first time and liver retransplantation as well.