Novel benchmark values for redo liver transplantation – does the outcome justify the effort?

Objective

In the era of organ shortage, redo liver transplantation (reLT) is frequently discussed in terms of expected poor outcome, high cost and therefore wasteful resources. However, there is a lack of benchmark data to reliably assess outcomes after reLT. The aim of this study was to define the ideal reLT case, and to establish clinically relevant benchmark values for best achievable outcome in reLT.

Methods

We collected data on reLT between January 2010 and December 2018 from 22 high volume transplant centers on three continents. Benchmark cases were defined as recipients with model of end-stage liver disease score <=25, absence of portal vein thrombosis, no mechanical ventilation before surgery, receiving a graft from a donor after brain death. In addition, early reLT including those for primary non-function (PNF) were excluded. Clinically relevant endpoints covering intra- and postoperative course were selected and complications were graded by severity using the Clavien-Dindo classification and the comprehensive complication index (CCI). The benchmark cutoff for each outcome was derived from the 75th percentile of the median values of all benchmark centers, indicating the “best achievable” result. To assess the utility of the newly established benchmark values, we analyzed patients who received reLT for PNF (non-benchmark patients).

Results

Out of 1110 reLT 413 (37.2%) qualified as benchmark cases. Benchmark values included: Length of intensive care unit and hospital stay: <=6 and <=24 days, respectively; Clavien-Dindo grade >=3a complications and the CCI at 1 year: <=76% and <=72.2, respectively; in-hospital and 1-year mortality rates: <=14.0% and <=14.3%, respectively. The cutoffs for transplant-specific complications such as biliary complications at 1 year, outflow problems at 1 year and hepatic artery thrombosis at discharge were <=27.3%, <=2.5% and <=4.8%, respectively. Patients receiving a reLT for PNF showed mean outcome values all outside the reLT benchmark values. In-hospital mortality rate was 34.4% and the mean CCI at discharge 68.8.

Conclusion

ReLT remains associated with high morbidity and mortality. The availability of benchmark values for outcome parameters of reLT may serve for comparison in any future analyses of individuals, patient groups, or centers, but also in the evaluation of new therapeutic strategies and principles.

Assessment and optimization of liver volume before major hepatic resection: Current guidelines and a narrative review

Post hepatectomy liver failure (PHLF) remains a significant cause of morbidity and mortality after major liver resection. Although the etiology of PHLF is multifactorial, an inadequate functional liver remnant (FLR) is felt to be the most important modifiable predictor of PHLF. Pre-operative evaluation of FLR function and volume is of paramount importance before proceeding with any major liver resection. Patients with inadequate or borderline FLR volume must be considered for volume optimization strategies such as portal vein embolization (PVE), two stage hepatectomy with portal vein ligation (PVL), Yttrium-90 radioembolization, and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). This paper provides an overview of assessing FLR volume and function, and discusses indications and outcomes of commonly used volume optimization strategies.

Hepatic venous outflow obstruction in pediatric liver transplantation: technical considerations in prevention, diagnosis, and management

HVOO creates significant diagnostic and management dilemmas in pediatric liver transplant recipients, particularly with TVGs (split or reduced-size grafts). Numerous technical variations for the hepatic vein to IVC anastomosis have been described to minimize the incidence of this complication, but no consensus for an optimal anastomotic technique exists. One hundred and thirty-four liver transplants (70 TVGs) were performed in 124 patients between 1994 and 2011. These were divided into two cohorts. Group 1 (95 transplants, 41 TVGs) utilized a continuous running anastomosis. Group 2 (39 transplants, 29 TVGs) implemented a triangulated (three-stitch) anastomosis. All were reviewed for demographics, diagnostics, interventions, and outcome. The overall HVOO incidence was seven of 134 transplants (5.2%) and six of 70 transplants utilizing TVGs (8.6%). Group 1 incidence was five of 41 (12.2%) compared with one of 29 (3.4%; p = 0.20, OR 3.89) in Group 2. Liver Doppler was employed in all patients, and only three suggested HVOO. All patients with HVOO underwent venogram, at a median of 81 days post-transplant. All underwent percutaneous venoplasty and required 1-6 treatments, all resulting in HVOO resolution. Incidence of HVOO has improved since adopting the triangulated anastomosis, although not to a level of statistical significance. US is not adequately sensitive to exclude HVOO. Venogram is recommended in patients with prolonged ascites, and venoplasty has been highly successful in HVOO treatment.

Immune responses to collagen-IV and fibronectin in renal transplant recipients with transplant glomerulopathy

Antibodies (Abs) to donor HLA (donor-specific antibodies [DSA]) have been associated with transplant glomerulopathy (TG) following kidney transplantation (KTx). Immune responses to tissue-restricted self-antigens (self-Ags) have been proposed to play a role in chronic rejection. We determined whether KTx with TG have immune responses to self-Ags, Collagen-IV (Col-IV) and fibronectin (FN). DSA were determined by solid phase assay, Abs against Col-IV and FN by enzyme-linked immunosorbent assay and CD4+ T cells secreting interferon gamma (IFN-γ), IL-17 or IL-10 by ELISPOT. Development of Abs to self-Ags following KTx increased the risk for TG with an odds ratio of 22 (p-value = 0.001). Abs to self-Ags were IgG and IgM isotypes. Pretransplant Abs to self-Ags increased the risk of TG (22% vs. 10%, p < 0.05). Abs to self-Ags were identified frequently in KTx with DSA. TG patients demonstrated increased Col-IV and FN specific CD4+ T cells secreting IFN-γ and IL-17 with reduction in IL-10. We conclude that development of Abs to self-Ags is a risk factor and having both DSA and Abs to self-Ags increases the risk for TG. The increased frequency of self-Ag-specific IFN-γ and IL-17 cells with reduction in IL-10 demonstrate tolerance breakdown to self-Ags which we propose play a role in the pathogenesis of TG.

A novel organ donor facility: a decade of experience with liver donors

Transplant surgeons have historically traveled to donor hospitals, performing complex, time-sensitive procedures with unfamiliar personnel. This often involves air travel, significant delays, and frequently occurs overnight.In 2001, we established the nation's first organ recovery center. The goal was to increase efficiency,reduce costs and reduce surgeon travel. Liver donors and recipients, donor costs, surgeon hours and travel time, from April 1,2001 through December 31,2011 were analyzed. Nine hundred and fifteen liver transplants performed at our center were analyzed based on procurement location (living donors and donation after cardiac death donors were excluded). In year 1, 36% (9/25) of donor procurements occurred at the organ procurement organization (OPO) facility, rising to 93%(56/60) in the last year of analysis. Travel time was reduced from 8 to 2.7 h (p<0.0001), with a reduction of surgeon fly outs by 93% (14/15) in 2011. Liver organ donor charges generated by the donor were reduced by37% overall for donors recovered at the OPO facility versus acute care hospital. Organs recovered in this novel facility resulted in significantly reduced surgeon hours, air travel and cost. This practice has major implications for cost containment and OPO national policy and could become the standard of care.

Renal function at two years in liver transplant patients receiving everolimus: results of a randomized, multicenter study

In a 24-month prospective, randomized, multicenter, open-label study, de novo liver transplant patients were randomized at 30 days to everolimus (EVR) + Reduced tacrolimus (TAC; n = 245), TAC Control (n = 243) or TAC Elimination (n = 231). Randomization to TAC Elimination was stopped prematurely due to a significantly higher rate of treated biopsy-proven acute rejection (tBPAR). The incidence of the primary efficacy endpoint, composite efficacy failure rate of tBPAR, graft loss or death postrandomization was similar with EVR + Reduced TAC (10.3%) or TAC Control (12.5%) at month 24 (difference -2.2%, 97.5% confidence interval [CI] -8.8%, 4.4%). BPAR was less frequent in the EVR + Reduced TAC group (6.1% vs. 13.3% in TAC Control, p = 0.010). Adjusted change in estimated glomerular filtration rate (eGFR) from randomization to month 24 was superior with EVR + Reduced TAC versus TAC Control: difference 6.7 mL/min/1.73 m(2) (97.5% CI 1.9, 11.4 mL/min/1.73 m(2), p = 0.002). Among patients who remained on treatment, mean (SD) eGFR at month 24 was 77.6 (26.5) mL/min/1.73 m(2) in the EVR + Reduced TAC group and 66.1 (19.3) mL/min/1.73 m(2) in the TAC Control group (p < 0.001). Study medication was discontinued due to adverse events in 28.6% of EVR + Reduced TAC and 18.2% of TAC Control patients. Early introduction of everolimus with reduced-exposure tacrolimus at 1 month after liver transplantation provided a significant and clinically relevant benefit for renal function at 2 years posttransplant.

Everolimus with reduced tacrolimus improves renal function in de novo liver transplant recipients: a randomized controlled trial

In a prospective, multicenter, open-label study, de novo liver transplant patients were randomized at day 30±5 to (i) everolimus initiation with tacrolimus elimination (TAC Elimination) (ii) everolimus initiation with reduced-exposure tacrolimus (EVR+Reduced TAC) or (iii) standard-exposure tacrolimus (TAC Control). Randomization to TAC Elimination was terminated prematurely due to a higher rate of treated biopsy-proven acute rejection (tBPAR). EVR+Reduced TAC was noninferior to TAC Control for the primary efficacy endpoint (tBPAR, graft loss or death at 12 months posttransplantation): 6.7% versus 9.7% (-3.0%; 95% CI -8.7, 2.6%; p<0.001 for noninferiority [12% margin]). tBPAR occurred in 2.9% of EVR+Reduced TAC patients versus 7.0% of TAC Controls (p = 0.035). The change in adjusted estimated GFR from randomization to month 12 was superior with EVR+Reduced TAC versus TAC Control (difference 8.50 mL/min/1.73 m(2) , 97.5% CI 3.74, 13.27 mL/min/1.73 m(2) , p<0.001 for superiority). Drug discontinuation for adverse events occurred in 25.7% of EVR+Reduced TAC and 14.1% of TAC Controls (relative risk 1.82, 95% CI 1.25, 2.66). Relative risk of serious infections between the EVR+Reduced TAC group versus TAC Controls was 1.76 (95% CI 1.03, 3.00). Everolimus facilitates early tacrolimus minimization with comparable efficacy and superior renal function, compared to a standard tacrolimus exposure regimen 12 months after liver transplantation.

The role of liver transplantation for hepatic adenomatosis in the pediatric population: case report and review of the literature

Hepatic adenomas are benign lesions often found in young women during childbearing age. These tumors are often solitary but can also be multiple in which case this is referred to as hepatic adenomatosis (HA). HA is defined as having greater than or equal to ten adenomas within an otherwise normal liver. We present a case of a teenager with HA who underwent an orthotopic liver transplant for complications of her HA. To date there are only four reports of teenagers, without an underlying glycogen storage disease, who have undergone a liver transplant for HA. Liver transplantation within the pediatric population is an acceptable treatment for HA that are deemed unresectable.

Improved islet yields from pancreas preserved in perflurocarbon is via inhibition of apoptosis mediated by mitochondrial pathway

Islet transplantation is a treatment option for type I diabetic patients. Preservation of human pancreata prior to islet isolation using two-layer method with perfluorocarbon (PFC) and University of Wisconsin solution (UW) results in twofold increase in islet yields. The objective of this study was to determine the mechanism by which islets undergo apoptosis and determine PFC's effects on this process. Gene array analysis was used to analyze the expression of pro- and anti-apoptotic genes in islets isolated from pancreata preserved under varying conditions. A 12-fold increase in the expression of inhibitor of apoptosis (IAP) and survivin was observed in islets isolated from pancreata preserved in PFC. This was accompanied by decreased expression of BAD (3.7-fold), BAX (2.7-fold) and caspases (5.2-fold). Levels of activated caspase-9 (77.98%), caspase-2 (61.5%), caspase-3 (68.3%) and caspase-8 (37.2%) were also reduced. 'Rescue' of pancreata after storage (12 h) in UW by preservation using PFC also resulted in a down-regulation of pro-apoptotic genes and inhibition of caspase activation. Apoptosis observed in islets from all groups was mainly mitochondria-dependent, mediated by change in redox potential initiated by hypoxia. We demonstrate that reduction in hypoxia of pancreata preserved using PFC leads to significant up-regulation of anti-apoptotic and inhibition of pro-apoptotic genes.

Liver transplantation in a patient with undiagnosed bipolar disorder

We present the case of a 55-year-old woman with no previous diagnosis of bipolar disorder, who underwent orthotopic liver transplantation for hepatitis C and alcohol-related liver disease. Two weeks posttransplant, she exhibited manic symptoms including hyperactivity, racing thoughts, and pressured speech. Although drug and alcohol abuse had been in remission for a 10-year period, a long history consistent with bipolar disorder was only identified after surgery. This article discusses the role of psychiatric evaluation prior to undergoing liver transplantation, and provides the transplant team with suggestions for comprehensively assessing psychiatric disorders in addition to alcohol and drug use.

Radical resection improves survival for patients with pT2 gallbladder carcinoma

Radical resection (wedge resection of the gallbladder bed and dissection of the hepatoduodenal ligament, portal, and celiac lymph nodes) has been reported to improve survival from pathologic T2 gallbladder carcinoma (pT2 GBCa; invasion through the muscularis without perforation of the serosa). We report our experience and the outcome of patients with pT2 GBCa. Between 1989 and 2000 at Vanderbilt University Medical Center ten patients were found to have pT2 disease after cholecystectomy. The patients had an average age of 64+/-13 years and underwent either radical resection (n = 5) or no further surgical therapy (n = 5). Of the patients who underwent cholecystectomy only, one (20%) is still alive at 27 months and four (80%) died of recurrent GBCa between 6.5 and 21 months. For the patients who underwent radical resection all five are alive at 15 to 83 months with no recurrence. The proportion of patients surviving pT2 GBCa after radical resection was significantly greater than with cholecystectomy alone (P < 0.05). The difference in length of survival between the two groups was also significant (P < 0.05). Morbidity after radical resection was low (pancreatic leak in one patient), and there were no operative mortalities. Radical resection significantly improved survival over cholecystectomy alone for patients with pT2 GBCa. The procedure has low morbidity and mortality rates. Therefore a radical resection operation is indicated for patients with pT2 GBCa.

Bile duct injury following laparoscopic cholecystectomy: a cause for continued concern

Previous reports suggest that bile duct injuries sustained during laparoscopic cholecystectomy (lap chole) are frequently severe and related to cautery and high clip ligation. We performed a review of patients who sustained bile duct injury from lap chole since 1990 and assessed time to injury recognition, time to referral, Bismuth classification, initial and subsequent repairs, rate of recurrence, and length of follow-up. Seventy-four patients [median age 44 years, 58 of 74 female (78%)] were referred with a bile duct injury after lap chole. The level of injury was evenly divided between the bile duct bifurcation and the common hepatic duct: Bismuth III, IV, and V (40 of 74, 54%) versus Bismuth I and II (34 of 74, 46%). Concomitant hepatic arterial injury was identified in nine (12%) patients. Patients referred early after bile duct injury and requiring operative intervention underwent hepaticojejunostomy at a median of 2 days after referral. After surgical reconstruction at our center there has been an overall success rate of 89 per cent with no need for reintervention. Six (10%) of these patients have required one additional balloon dilatation at a mean follow-up of >24 months. One (2%) patient underwent biliary-enteric revision in follow-up. In patients with bile duct injury, stricture repair without delay was successful in the majority of patients treated in this series. Only one of 64 patients reconstructed at our center has required reoperation; six others have required a single balloon dilatation with subsequent good or excellent results. The majority of patients treated with operative repair at an experienced center can expect good long-term results with rare need for reintervention.

Effect of dopamine infusion on hemodynamics after hepatic denervation

BACKGROUND

. The effects of dopamine (DA) on systemic hemodynamics are better understood than its effects on hepatic hemodynamics, especially after liver denervation occurring during liver transplantation. Therefore, a porcine model was used to study DA's effects on hemodynamics after hepatic denervation.

MATERIALS AND METHODS

Fifteen pigs underwent laparotomy for catheter and flow probe placement. The experimental group (n = 7) also underwent hepatic denervation. After 1 week, all pigs underwent DA infusion at increasing doses (3-30 mcg/kg/min) while measuring hepatic parameters [portal vein flow (PVF), hepatic artery flow (HAF), total hepatic blood flow (THBF = HAF + PVF), portal and hepatic vein pressures] and systemic parameters [heart rate (HR), mean arterial pressure (MAP)].

RESULTS

There was a significant increase in HAF from baseline to the 30 mcg/kg/min DA infusion rate (within-subjects P < 0.01), but the differences between the two groups were not significant. PVF and THBF showed large effects (increases) with denervation, but the increase in flow with DA infusion was not present after denervation. Perihepatic pressures were unchanged by denervation or DA. Heart rate differed significantly between the control and denervated animals at baseline, 3, 6, 12 (all P < 0.05), and 30 mcg/kg/min DA (P = 0.10). Control vs denervation MAP at baseline was 100 +/- 4 vs 98 +/- 4 Torr and at 30 mcg/kg/min it was 110 +/- 3 vs 101 +/- 5 mm Hg.

CONCLUSIONS

Hepatic flows tended to be higher after denervation. HAF showed similar increases with DA in both control and denervation groups. Increases in PVF and THBF with DA infusion were not present after denervation. HR was significantly decreased and MAP tended to be lower after denervation. The HR and MAP response to DA was similar in both groups. Therefore, both denervation and DA infusion have an effect on systemic and hepatic hemodynamics.

Control of bone bleeding at the sternum and iliac crest donor sites using a collagen-based composite combined with autologous plasma: results of a randomized controlled trial

In a randomized controlled trial, hemostatic effectiveness of a collagen-based composite (experimental group) was compared with standard hemostatic methods (ie, electrocautery and collagen sponge) (control group) at two bone sites. Hemostatic success, time to "controlled bleeding," and time to "complete hemostasis" were determined at the sternal edge following median sternotomy (n=64) and at the iliac crest following bone graft harvest (n=19). Almost twice the percentage of sternal edge patients (83% versus 44%, P=.002) and nearly three times the percentage of iliac crest patients (83% versus 29%, P<.05) achieved complete hemostasis in the experimental group compared to controls. Time to controlled bleeding and complete hemostasis for all bone sites also favored the experimental group over the control group at highly significant levels (P<.0001 for most comparisons). There were no adverse events related to experimental treatment use. The results support the use of this investigational hemostatic agent to control cancellous bone bleeding.

Hepatic cryoablation-induced acute lung injury: histopathologic findings

We have previously shown that hepatic cryoablation (cryo), but not partial hepatectomy, induces a systemic inflammatory response, with distant organ injury and overproduction of NF-kappaB-dependent cytokines. Serum tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 (MIP-2) levels are markedly increased 1 h and beyond after cryo compared with partial hepatectomy where no elevation occurs. NF-kappaB activation (by electrophoretic mobility shift assay) is strikingly increased in the noncryo liver (but not in the lung) at 30 min and in both the liver and lung tissue 1 h after cryo, returning to the baseline by 2 h and beyond. The current study investigated the histopathologic changes associated with cryoablation-induced acute lung injury. Animals underwent 35% hepatic resection or a similar volume hepatic cryo and were sacrificed at 1, 2, 6, and 24 h. Pulmonary histologic features were assessed using hematoxylin and eosin and immunoperoxidase staining with a macrophage-specific antibody (anti-lysozyme, 1:200 dilution, Dako, Carpinteria, CA). The following features were graded semiquantitatively (0-3): perivascular lymphoid cuffs, airspace edema and hemorrhage, margination of neutrophils within pulmonary vasculature, and the presence of macrophages with foamy cytoplasm in the pulmonary interstitium. Hepatic resection (n = 21) resulted in slight perivascular edema at 1, 2, 6, and 24 h post-resection, but there were no other significant changes. Pulmonary findings after hepatic cryo (n = 22) included prominent perivascular lymphoid cuffs 1 and 2 h following hepatic injury that were not present at any other time point (P 0.01). Marginating PMNs and foamy macrophages were more common after cryo at all time points (P<0.05, cryo vs resection). Severe lung injury, as evidenced by airspace edema and parenchymal hemorrhage, was present in four of six (67%) animals at 24 h (P 0.03). In follow-up studies immediate resection (n = 15) of the cryo-treated liver prior to thawing prevented the pulmonary changes. The findings of pulmonary perivascular interstitial macrophages 2 h following hepatic cryo suggests that hepatic cytokine production may induce downstream recruitment of pulmonary macrophages, which may contribute to subsequent severe lung injury. This study suggests that a soluble mediator from direct liver injury leads to neutrophilic lung inflammation and this is associated with the thawing phase of cryoablation.

Registration of physical space to laparoscopic image space for use in minimally invasive hepatic surgery

While laparoscopes are used for numerous minimally invasive (MI) procedures, MI liver resection and ablative surgery is infrequently performed. The paucity of cases is due to the restriction of the field of view by the laparoscope and the difficulty in determining tumor location and margins under video guidance. By merging MI surgery with interactive, image-guided surgery (IIGS), we hope to overcome localization difficulties present in laparoscopic liver procedures. One key component of any IIGS system is the development of accurate registration techniques to map image space to physical or patient space. This manuscript focuses on the accuracy and analysis of the direct linear transformation (DLT) method to register physical space with laparoscopic image space on both distorted and distortion-corrected video images. Experiments were conducted on a liver-sized plastic phantom affixed with 20 markers at various depths. After localizing the points in both physical and laparoscopic image space, registration accuracy was assessed for different combinations and numbers of control points (n) to determine the quantity necessary to develop a robust registration matrix. For n = 11, average target registration error (TRE) was 0.70 +/- 0.20 mm. We also studied the effects of distortion correction on registration accuracy. For the particular distortion correction method and laparoscope used in our experiments, there was no statistical significance between physical to image registration error for distorted and corrected images. In cases where a minimum number of control points (n = 6) are acquired, the DLT is often not stable and the mathematical process can lead to high TRE values. Mathematical filters developed through the analysis of the DLT were used to prospectively eliminate outlier cases where the TRE was high. For n = 6, prefilter average TRE was 17.4 +/- 153 mm for all trials; when the filters were applied, average TRE decreased to 1.64 +/- 1.10 mm for the remaining trials.

Effective control of hepatic bleeding with a novel collagen-based composite combined with autologous plasma: results of a randomized controlled trial

HYPOTHESIS

A novel collagen-based composite of bovine microfibrillar collagen and bovine thrombin combined with autologous plasma is more effective than standard hemostasis (collagen sponge applied with pressure) in controlling diffuse hepatic bleeding after hemihepatectomy or segmental resection of the liver.

DESIGN

Randomized controlled trial.

SETTING

Seven university-affiliated medical centers.

PATIENTS

Sixty-seven adult patients scheduled for hemihepatectomy or segmental resection who received hemostatic intervention with an investigational treatment (n = 38) or control (n = 29).

INTERVENTION

Bleeding hepatic tissue was managed in all control subjects with a collagen sponge with manual pressure. Subjects in the experimental group had the sprayable liquid composite intraoperatively applied to the surgical site. The liquid immediately formed a collagen-fibrin gel that was used without concomitant tamponade.

MAIN OUTCOME MEASURES

Hemostatic success was defined as the proportion of subjects in each treatment group who achieved complete hemostasis within 10 minutes. Success rates and median times required to achieve controlled bleeding (ie, slight oozing) and complete hemostasis were compared between treatment groups.

RESULTS

All 38 subjects in the experimental group achieved complete hemostasis within 10 minutes compared with only 69% (20/29) of control subjects (P<.001). The median time to controlled bleeding was approximately 4 times longer (250 vs 62 seconds) for control subjects than for experimental group subjects (P<.001). The median time required to achieve complete hemostasis also favored the experimental group (150 vs 360 seconds; P<.001). No adverse events related to the use of the experimental hemostatic agent were detected.

CONCLUSIONS

The experimental composite is more effective at controlling and stopping diffuse hepatic bleeding than a collagen sponge applied with pressure; it may be a useful hemostatic agent for patients undergoing hemihepatectomy, segmental resection, and related surgical procedures.

Technical advances toward interactive image-guided laparoscopic surgery

BACKGROUND

Laparoscopic surgery uses real-time video to display the operative field. Interactive image-guided surgery (IIGS) is the real-time display of surgical instrument location on corresponding computed tomography (CT) scans or magnetic resonance images (MRI). We hypothesize that laparoscopic IIGS technologies can be combined to offer guidance for general surgery and, in particular, hepatic procedures. Tumor information determined from CT imaging can be overlayed onto laparoscopic video imaging to allow more precise resection or ablation.

METHODS

We mapped three-dimensional (3D) physical space to 2D laparoscopic video space using a common mathematical formula. Inherent distortions present in the video images were quantified and then corrected to determine their effect on this 3D to 2D mapping.

RESULTS

Errors in mapping 3D physical space to 2D video image space ranged from 0.65 to 2.75 mm.

CONCLUSIONS

Laparoscopic IIGS allows accurate (<3.0 mm) confirmation of 3D physical space points on video images. This in combination with accurately tracked instruments and an appropriate display may facilitate enhanced image guidance during laparoscopy.

Hepatic cryoablation-induced acute lung injury: pulmonary hemodynamic and permeability effects in a sheep model

HYPOTHESIS

Hepatic cryoablation of 30% to 35% or more of liver parenchyma in a sheep model results in eicosanoid and nuclear factor-kappaB (NF-kappaB)-mediated changes in pulmonary hemodynamics and lung permeability.

SETTING

Laboratory.

INTERVENTIONS

At initial thoracotomy, catheters were placed in the main pulmonary artery, left atrium, right carotid artery, and efferent duct of the caudal mediastinal lymph node for subsequent monitoring in adult sheep. After a 1- to 2-week period of recovery, animals underwent laparotomy and left-lobe cryoablation (approximately 35% by volume) with subsequent awake monitoring and on postoperative days 1 to 3.

MAIN OUTCOME MEASURES

Cryoablation-induced lung permeability and hemodynamic changes were compared with baseline values in sheep that underwent instrumentation. Similarly handled sheep underwent resection of a similar volume of hepatic parenchyma or had pulmonary artery pressure increases induced by mechanical left atrial obstruction. Activation of NF-kappaB was assessed with electrophoretic mobility shift assay, and serum thromboxane levels were measured with mass spectroscopy.

RESULTS

Cryoablation resulted in acutely increased mean pulmonary (20 to 35 cm water) and systemic pressures, which returned to baseline at 24 hours with no change in cardiac output. Serum thromboxane levels increased 30 minutes after cryoablation (9-fold) and returned to baseline at 24 hours. Activation of NF-kappaB was present in liver and lung tissue by 30 minutes after cryoablation. Lung lymph-plasma protein clearance markedly exceeded the expected increase from pulmonary pressures alone, and increased lymph-plasma protein ratio persisted after pulmonary artery pressures normalized. Similar changes were not associated with 35% hepatic resection.

CONCLUSIONS

This study demonstrates that 35% hepatic cryoablation results in an acute but transient increase in pulmonary artery pressure that may be mediated by increased thromboxane levels. Increases in pulmonary capillary permeability are not accounted for by pressure changes alone, and may be a result of NF-kappaB-mediated inflammatory mechanisms. These data show that cryosurgery causes pathophysiological changes similar to those observed with endotoxin and other systemic inflammatory stimuli.

Surface registration for use in interactive, image-guided liver surgery

OBJECTIVE

Liver surgery is difficult because of limited external landmarks, significant vascularity, and inexact definition of intra-hepatic anatomy. Intra-operative ultrasound (IOUS) has been widely used in an attempt to overcome these difficulties, but is limited by its two-dimensional nature, inter-user variability, and image obliteration with ablative or resectional techniques. Because the anatomy of the liver and intra-operative removal of hepatic ligaments make intrinsic or extrinsic point-based registration impractical, we have implemented a surface registration technique to map physical space into CT image space, and have tested the accuracy of this method on an anatomical liver phantom with embedded tumor targets.

MATERIALS AND METHODS

Liver phantoms were created from anatomically correct molds with "tumors" embedded within the substance of the liver. Helical CT scans were performed with 3-mm slices. Using an optically active position sensor, the surface of the liver was digitized according to anatomical segments. A surface registration was performed and RMS errors of the locations of internal tumors are presented as verification. An initial point-based marker registration was performed and considered the "gold standard" for error measurement.

RESULTS

Errors for surface registration were 2.9 mm for the entire surface and 2.8 mm for embedded targets.

CONCLUSION

This is an initial study considering the use of surface registration for the purpose of physical-to-image registration in the area of liver surgery.

Hepatic cryoablation, but not radiofrequency ablation, results in lung inflammation

OBJECTIVE

To compare the effects of 35% hepatic cryoablation with a similar degree of radiofrequency ablation (RFA) on lung inflammation, nuclear factor kappaB (NF-kappaB) activation, and production of NF-kappaB dependent cytokines.

SUMMARY BACKGROUND DATA

Multisystem injury, including acute lung injury, is a severe complication associated with hepatic cryoablation of 30% to 35% or more of liver parenchyma, but this complication has not been reported with RFA.

METHODS

Sprague-Dawley rats underwent 35% hepatic cryoablation or RFA and were killed at 1, 2, and 6 hours. Liver and lung tissue were freeze-clamped for measurement of NF-kappaB activation, which was detected by electrophoretic mobility shift assay. Serum concentrations of tumor necrosis factor alpha and macrophage inflammatory protein 2 were measured by enzyme-linked immunosorbent assay. Histologic studies of pulmonary tissue and electron microscopy of ablated liver tissue were compared among treatment groups.

RESULTS

Histologic lung sections after cryoablation showed multiple foci of perivenular inflammation, with activated lymphocytes, foamy macrophages, and neutrophils. In animals undergoing RFA, inflammatory foci were not present. NF-kappaB activation was detected at 1 hour in both liver and lung tissue samples of animals undergoing cryoablation but not after RFA, and serum cytokine levels were significantly elevated in cryoablation versus RFA animals. Electron microscopy of cryoablation-treated liver tissue demonstrated disruption of the hepatocyte plasma membrane with extension of intact hepatocyte organelles into the space of Disse; RFA-treated liver tissue demonstrated coagulative destruction of hepatocyte organelles within an intact plasma membrane. To determine the stimulus for systemic inflammation, rats treated with cryoablation had either immediate resection of the ablated segment or delayed resection after a 15-minute thawing interval. Immediate resection of the cryoablated liver tissue prevented NF-kappaB activation and lung injury; however, pulmonary inflammatory changes were present when as little as a 15-minute thaw interval preceded hepatic resection.

CONCLUSIONS

Hepatic cryoablation, but not RFA, induces NF-kappaB activation in the nonablated liver and lung and is associated with acute lung injury. Lung inflammation is associated with the thawing phase of cryoablation and may be related to soluble mediator(s) released from the cryoablated tissue. These findings correlate the clinical observation of an increased incidence of multisystem injury, including adult respiratory distress syndrome (ARDS), after cryoablation but not RFA.

The incidence of splenectomy is decreasing: lessons learned from trauma experience

Over the past decade, splenic preservation has become a well-reported and accepted principle in trauma management. The reasons for splenic preservation may have influenced nontraumatic surgical management as well. To investigate the changing incidence and indications for splenectomy, we conducted a 10-year review of all splenectomies at our institution. During this time, between January 1, 1986, and December 31, 1995, 896 patients underwent splenectomy. Hospital charts and records were examined to determine the etiology and incidence of splenectomy. Indications were classified as: 1) trauma, i.e., performed for blunt or penetrating injury; 2) hematologic malignancy, i.e., therapy or staging of underlying leukemia, Hodgkin's lymphoma, or non-Hodgkin's lymphoma; 3) cytopenia, i.e., treatment of thrombocytopenia, anemia, or leukopenia; 4) iatrogenic, i.e., injury during another procedure; 5) incidental, i.e., required for adjacent organ resection; 6) portal hypertension, i.e., left-sided portal hypertension or during shunting procedure; 7) diagnostic, i.e., uncertainty excluding hematologic malignancy; or 8) other, i.e., miscellaneous indications. Trauma accounted for 41.5 per cent of all splenectomies during this time period, hematologic malignancy 15.4 per cent, cytopenia 15.6 per cent, incidental 12.3 per cent, iatrogenic 8.1 per cent, portal hypertension 2.3 per cent, diagnostic 2.0 per cent, and other 2.7 per cent. Comparing the first and second 5-year time periods, the following increases/decreases in average annual incidence were noted: splenectomy for all indications, -36.9 per cent; trauma, -32.9 per cent; hematologic malignancy, -51.4 per cent; cytopenia, 35.1 per cent; incidental, -35.9 per cent; iatrogenic, -30.2 per cent; diagnostic, +4.9 per cent, and other, -57 per cent. Traumatic injury to the spleen remains the most common indication for splenectomy, but the incidence has decreased dramatically over the past 10 years. Splenectomies for treatment of hematologic malignancies and cytopenia, as well as incidental and iatrogenic splenectomies, have also decreased significantly. Only the incidence of diagnostic splenectomy has remained stable. Although initiated within the field of trauma, the advantages of splenic preservation now appear to be well recognized beyond that field.

Embryology, anatomy, and surgical applications of the extrahepatic biliary system

As technology has improved and the ability to apply this technology in the surgical arena has grown, surgeons have been able to perform more sophisticated operative procedures. Hepatobiliary surgeons are now able to use laparoscopy, immunosuppressive drugs, and technical advances in cryosurgery to accomplish magnificent results. The success and safety of laparoscopic cholecystectomy, orthotopic liver transplantation, and trisegmentectomy for hepatic tumors depend on a high regard for and an accurate knowledge of the anatomy and some of the common embryologic anomalies of the biliary tree. The blood supply, ductal variations, and gallbladder anatomy of this area are often the source of major challenge to unprepared and unaware surgeons. The authors have attempted to stimulate an interest in, a respect for, and perhaps some desire to learn more about the important and fascinating anatomy of this region.

Effect of dopamine infusion (3-30 microg/kg/min) on hepatic hemodynamics

BACKGROUND

While dopamine produces well-characterized dose-dependent effects on systemic hemodynamics, there is a paucity of information regarding its effects on hepatic hemodynamics. Infusion rates above 10 microg/kg/min are reported to produce significant vasoconstriction and impair organ perfusion. Therefore, donors are sometimes considered unsuitable when higher doses of dopamine are in use. The aim of this study was to determine the effect of increasing doses of dopamine on hepatic hemodynamics in a nonanesthetized swine model.

MATERIALS AND METHODS

Sixteen pigs were instrumented with indwelling catheters in a peripheral artery, peripheral vein, portal vein, and hepatic vein and flow probes around the portal vein and hepatic artery. After recovery, the following variables were measured 10 +/- 1 days postinstrumentation: hepatic arterial flow (HAF), portal venous flow (PVF), mean systemic arterial pressure (MAP), central venous pressure (CVP), portal venous pressure (PVP), hepatic venous pressure (HVP), heart rate (HR). Recordings were obtained at baseline and subsequently when dopamine was infused at rates of 3, 6, 12, 15, 21, and 30 microg/kg/min increasing at 1-h intervals.

RESULTS

HAF and PVF increased linearly over the entire infusion range, to 69 and 13% over baseline, respectively (P < 0.001, P < 0.05). Total hepatic blood flow rose 23% over baseline at the 30 microg/kg/min dosage (P < 0.01). MAP increased linearly 13% over the range 12 to 30 microg/kg/min (P < 0.001). CVP, HVP, and PVP did not change significantly. HR decreased from 12 to 15 microg/kg/min (P < 0.01), then increased from 15 to 30 microg/kg/min (P < 0.05).

CONCLUSION

These data show that dopamine infused at dosages of 3-30 microg/kg/min augments HAF, PVF, and THBF and that this effect is linear. These results suggest high-dose dopamine infusion does not disqualify a potential donor liver for transplantation.

Optimal interpretation of FDG PET in the diagnosis, staging and management of pancreatic carcinoma

This study had two purposes: to optimize the semiquantitative interpretation of 18F-fluorodeoxyglucose (FDG) PET scans in the diagnosis of pancreatic carcinoma by analyzing different cutoff levels for the standardized uptake value (SUV), with and without correction for serum glucose level (SUV(gluc)); and to evaluate the usefulness of FDG PET when used in addition to CT for the staging and management of patients with pancreatic cancer.

METHODS

Sixty-five patients who presented with suspected pancreatic carcinoma underwent whole-body FDG PET in addition to CT imaging. The PET images were analyzed visually and semiquantitatively using the SUV and SUV(gluc). The final diagnosis was obtained by pathologic (n = 56) or clinical and radiologic follow-up (n = 9). The performance of CT and PET at different cutoff levels of SUV was determined, and the impact of FDG PET in addition to CT on patient management was reviewed retrospectively.

RESULTS

Fifty-two patients had proven pancreatic carcinoma, whereas 13 had benign lesions, including chronic pancreatitis (n = 10), benign biliary stricture (n = 1), pancreatic complex cyst (n = 1) and no pancreatic pathology (n = 1). Areas under receiver operating characteristic curves were not significantly different for SUV and SUV(gluc). Using a cutoff level of 3.0 for the SUV, FDG PET had higher sensitivity and specificity than CT in correctly diagnosing pancreatic carcinoma (92% and 85% versus 65% and 61%). There were 2 false-positive PET (chronic pancreatitis, also false-positive with CT) and 4 false-negative PET (all with true-positive CT, abnormal but nondiagnostic) examinations. There were 5 false-positive CT (4 chronic pancreatitis and 1 pancreatic cyst) and 18 false-negative CT (all with true-positive FDG PET scans) examinations. FDG PET clarified indeterminate hepatic lesions or identified additional distant metastases (or both) in 7 patients compared with CT. Overall, FDG PET altered the management of 28 of 65 patients (43%).

CONCLUSION

FDG PET is more accurate than CT in the detection of primary tumors and in the clarification and identification of hepatic and distant metastases. The optimal cutoff value of FDG uptake to differentiate benign from malignant pancreatic lesions was 2.0. Correction for serum glucose did not significantly improve the accuracy of FDG PET. Although FDG PET cannot replace CT in defining local tumor extension, the application of FDG PET in addition to CT alters the management in up to 43% of patients with suspected pancreatic cancer.

Acute pancreatitis after cardiac transplantation and other cardiac procedures: case-control analysis in 24,631 patients

Previous series have identified an increased risk of developing acute postoperative pancreatitis in heart transplant recipients and other cardiac surgical patients, and some suggest that mortality is significantly increased when pancreatitis occurs in the transplant setting. We conducted a retrospective case-control analysis of adult patients undergoing orthotopic heart transplant or other cardiac procedures from April 1985 through June 1996 at our medical center. Specific risk factors for outcome were assessed including low cardiac output, intra-aortic balloon pump usage, exogenous calcium repletion, immunosuppression, cytomegalovirus infection, cholelithiasis, prior pancreatitis, and Acute Physiology and Chronic Health Evaluation (APACHE) II scores. There was a 30-fold increase in the incidence of pancreatitis in the heart transplant group [12 of 394 (3%) vs 27 of 24,237 (0.1%); P < 0.01]. Compared with the nontransplant cardiopulmonary bypass patients, the transplant patients experienced a statistically significant increased incidence of immunosuppression and three or more risk factors. Transplant patients with pancreatitis demonstrated a significant increase in APACHE II scores and the incidence of three or more risk factors compared with their transplant control group. Patients undergoing nontransplant cardiac procedures and developing pancreatitis had significantly increased cross-clamp times, incidence of low cardiac output, APACHE II scores, and incidence of three or more risk factors compared with their nontransplant cohort. In conclusion, there is a significant increase in the incidence of pancreatitis after orthotopic heart transplant compared with other cardiac procedures. Analysis demonstrates the additive effect of multiple individual risk factors. Immunosuppression confers significant additional risk for pancreatitis in the orthotopic heart transplant patient.

Acute lung injury after hepatic cryoablation: correlation with NF-kappa B activation and cytokine production

BACKGROUND

Previous clinical reports have documented multisystem organ injury after hepatic cryoablation. We hypothesized that hepatic cryosurgery, but not partial hepatectomy, induces a systemic inflammatory response characterized by distant organ injury and overproduction of nuclear factor kappa B (NF-kappa B)-dependent, proinflammatory cytokines.

METHODS

In this study, rats underwent either cryoablation of 35% of liver parenchyma or a similar resection of left hepatic tissue. Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels and NF-kappa B activation were assessed by electrophoretic mobility shift assay at 30 minutes 1, 2, 6, and 24 hours after either procedure.

RESULTS

Cryoablation of 35% of liver (n = 22 rats) resulted in lung injury and a 45% mortality rate within 24 hours of surgery, whereas 7% treated with 35% hepatectomy (n = 15 rats) died during the 24 hours after surgery (P < .05, cryoablation vs hepatectomy). Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels were markedly increased in rats (n = 10 rats) 1 hour after hepatic cryoablation compared with rats that underwent partial hepatectomy (P < .005). We evaluated NF-kappa B activation by electrophoretic mobility shift assay in nuclear extracts of liver and lung after cryosurgery and found that NF-kappa B activation was strikingly increased in the liver but not the lung at 30 minutes and in both organs 1 hour after cryosurgery, and returned to baseline in both organs by 2 hours. In rats undergoing 35% hepatectomy, no increase in NF-kappa B activation was detected in nuclear extracts of either liver or lung at any time point.

CONCLUSIONS

These data show that hepatic cryosurgery results in systemic inflammation with activation of NF-kappa B and increased production of NF-kappa B-dependent cytokines. Our data suggest that lung injury and death in this animal model is mediated by an exaggerated inflammatory response to cryosurgery.

Antiperistaltic Roux-en-Y biliary-enteric bypass after bile duct injury: a technical error in reconstruction

Bilioenteric reconstruction using a Roux limb of jejunum is a well-established surgical option for the reconstruction of the proximal bile duct. Previous studies discussing short- and long-term complications of biliary-enteric anastomosis have focused on technical aspects, such as the use of anastomotic stenting or the level of the biliary tree used. We report two cases of previously unreported complications after hepaticojejunostomy that resulted from a technical error in constructing the Roux limb. Within a 3-month period, two patients were referred to our institution with recurrent cholangitis after biliary reconstruction for injuries sustained during laparoscopic cholecystectomy. Reexploration disclosed major technical flaws in the construction of the Roux limb used for biliary drainage. Antiperistaltic limbs had been constructed in both patients: one from the distal ileum and one from the conventional location in the jejunum. In both cases, isoperistaltic reconstruction of the Roux limbs resolved the recurrent cholangitis. Cholangitis after biliary-enteric bypass can arise from a variety of etiologies and lead to anastomotic narrowing or ineffective drainage of the biliary tree. Review of the literature failed to disclose reports of technically flawed Roux limb construction as a cause of cholangitis. We present these cases to highlight the devastating consequences of antiperistaltic construction of the Roux limb. We hope that by publishing the role of this avoidable error in recurrent cholangitis after biliary-enteric bypass we may help prevent its future occurrence.

Image-guided surgery: preliminary feasibility studies of frameless stereotactic liver surgery

BACKGROUND

Liver surgery can be difficult because there are few external landmarks defining hepatic anatomy and because the liver has significant vascularity. Although preoperative tomographic imaging (computed tomography or magnetic resonance imaging) provides essential anatomical information for operative planning, at present it cannot be used actively for precise localization during surgery. Interactive image-guided surgery involves the simultaneous real-time display of intraoperative instrument location on preoperative images (computed or positron-emission tomography or magnetic resonance imaging). Interactive image-guided surgery has been described for tumor localization in the brain (frameless stereotactic surgery) and allows for interactive use of preoperative images during resections or biopsies.

HYPOTHESIS

The application of interactive image-guided surgery (IIGS) is feasible for hepatic procedures from a biomedical engineering standpoint.

METHODS

We developed an interactive image-guided surgery system for liver surgery and tested a porcine liver model for tracking liver motion during insufflation; liver motion during respiration in open procedures in patients undergoing hepatic resection; and tracking accuracy of general surgical instruments, including a laparoscope and an ultrasound probe.

RESULTS

Liver motion due to insufflation can be quantified; average motion was 2.5+/-1.4 mm. Average total liver motion secondary to respiration in patients was 10.8 +/-2.5 mm. Instruments of varying lengths, including a laparoscope, can be tracked to accuracies ranging from 1.4 to 2.1 mm within a 27-m3 (3 X 3 X 3-m) space.

CONCLUSION

Interactive image-guided surgery appears to be feasible for open and laparoscopic hepatic procedures and may enhance future operative localization.

Surgical experience with hepatic colorectal metastasis

The outcome of 134 patients undergoing hepatic resection for colorectal metastasis was studied. Current follow-up was available in 98 per cent of patients, for more than 5 years in 58 patients, and totaling 360 patient-years. Patients (52% male) had an average age of 62 +/- 1 years (standard error of the mean). Time lapse between the primary colon surgery and hepatic resection was a median of 16 months and a mean of 19 +/- 1 months. Thirty-two (24%) were operated on within 6 months for both their primary tumor and hepatic metastasis. Intensive care unit and total hospital length of stay were a median of 1 and 7 days, respectively. Pathology reports demonstrated that on average there were 2.0 +/- 0.1 lesions, with the largest lesion measuring 4.4 +/- 0.2 cm. In 72 per cent of patients, the lesions were found in one lobe only. CEA was elevated in 83 per cent of patients preoperatively and was 60 +/- 11 ng/mL before and 4.0 +/- 0.5 ng/mL after hepatic resection. Patient survival was 81 per cent at 1 year, 50 per cent at 3 years, 36 per cent at 5 years, and 23 per cent at 10 years. Actual 5- and 10-year survival was 22 of 58 (38%) patients and 4 of 21 (19%) patients respectively. Disease-free survival was 58 per cent at 1 year, 27 per cent at 3 years, 16 per cent at 5 years, and 12 per cent at 7 years. Survival was much better for one to four lesions than for five or more lesions (P < 0.01). Several other potential risk factors did not affect survival, including whether the patient received chemotherapy after hepatic resection. There were 36 (43%) patients who recurred with hepatic involvement only, 27 (32%) including hepatic involvement and 21 (25%) with nonhepatic involvement only. There were 15 patients who went on to receive repeat hepatic resections, with a 5-year survival of 74 per cent and disease-free survival of 58 per cent. Hepatic resection provides the best outcome of any form of therapy for selected patients with isolated hepatic metastasis.

18Fluorodeoxyglucose-positron emission tomography in the management of patients with suspected pancreatic cancer

OBJECTIVE

To assess the accuracy and clinical impact of 18fluorodeoxyglucose-positron emission tomography (18FDG-PET) on the management of patients with suspected primary or recurrent pancreatic adenocarcinoma, and to assess the utility of 18FDG-PET in grading tumor response to neoadjuvant chemoradiation.

SUMMARY BACKGROUND DATA

The diagnosis, staging, and treatment of pancreatic cancer remain difficult. Small primary tumors and hepatic metastases are often not well visualized by computed tomographic scanning (CT), resulting in a high incidence of nontherapeutic celiotomy and the frequent need for "blind resection." In addition, the distinction between local recurrence and nonspecific postoperative changes after resection can be difficult to ascertain on standard anatomic imaging. 18FDG-PET is a new imaging technique that takes advantage of increased glucose metabolism by tumor cells and may improve the diagnostic accuracy of preoperative studies for pancreatic adenocarcinoma.

METHODS

Eighty-one 18FDG-PET scans were obtained in 70 patients undergoing evaluation for suspected primary or recurrent pancreatic adenocarcinoma. Of this group, 65 underwent evaluation for suspected primary pancreatic cancer. Nine patients underwent 18FDG-PET imaging before and after neoadjuvant chemoradiation, and in eight patients 18FDG-PET scans were performed for possible recurrent adenocarcinoma after resection. The 18FDG-PET images were analyzed visually and semiquantitatively using the standard uptake ratio (SUR). The sensitivity and specificity of 18FDG-PET and CT were determined for evaluation of the preoperative diagnosis of primary pancreatic carcinoma, and the impact of 18FDG-PET on patient management was retrospectively assessed.

RESULTS

Among the 65 patients evaluated for primary tumor, 52 had proven pancreatic adenocarcinoma and 13 had benign lesions. 18FDG-PET had a higher sensitivity and specificity than CT in correctly diagnosing pancreatic carcinoma (92% and 85% vs. 65% and 62%). Eighteen patients (28%) had indeterminate or unrecognized pancreatic masses on CT clarified with 18FDG-PET. Seven patients (11%) had indeterminate or unrecognized metastatic disease clarified with 18FDG-PET. Overall, 18FDG-PET suggested potential alterations in clinical management in 28/65 patients (43%) with suspected primary pancreatic adenocarcinoma. Of the nine patients undergoing 18FDG-PET imaging before and after neoadjuvant chemoradiation, four had evidence of tumor regression by PET, three showed stable disease, and two showed tumor progression. CT was unable to detect any response to neoadjuvant therapy in this group. Eight patients had 18FDG-PET scans to evaluate suspected recurrent disease after resection. Four were noted to have new regions of 18FDG-uptake in the resection bed; four had evidence of new hepatic metastases. All proved to have metastatic pancreatic adenocarcinoma.

CONCLUSIONS

These data confirm that 18FDG-PET is useful in the evaluation of patients with suspected primary or recurrent pancreatic carcinoma. 18FDG-PET is more sensitive and specific than CT in the detection of small primary tumors and in the clarification of hepatic and distant metastases. 18FDG-PET was also of benefit in assessing response to neoadjuvant chemoradiation. Although 18FDG-PET cannot replace CT in defining local tumor resectability, the application of 18FDG-PET in addition to CT may alter clinical management in a significant fraction of patients with suspected pancreatic cancer.

Transcatheter arterial chemoembolization as primary treatment for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) in Western populations has historically been associated with poor survival.

METHODS

In this study, we conducted a 7-year retrospective analysis of patients with HCC undergoing transcatheter arterial chemoembolization (TACE) at our institution and examined demographics, outcomes, and complications.

RESULTS

During the period of study, 39 patients (25 male [64%], mean age 58 [range 17 to 86]) underwent a total of 78 chemoembolization treatments. During the same time period, an additional 31 patients received supportive care only. The majority of patients had late stage disease (American Joint Committee on Cancer stage III, IVa, or IVb) with no statistical difference noted between the two groups (P = 0.2). However, patients receiving supportive care only had significantly worse hepatic dysfunction by Child's classification (P = 0.005). Twenty-nine patients (74%) had documented cirrhosis, with hepatitis C being the most common cause in 11 of 29 (38%). In patients undergoing TACE, overall actuarial survival was 35%, 20%, and 11% at 1, 2, and 3 years with a median survival of 9.2 months, significantly improved over the group receiving supportive care only (P < 0.0001). Median survival for the group receiving supportive care was less than 3 months. Neither age nor stage had a significant impact on survival. The most common complications of TACE included transient nausea, abdominal pain, vomiting, and fever.

CONCLUSIONS

TACE is a safe and effective therapeutic option for selected patients with HCC not amenable to surgical intervention.

Comparison of arcuate-legged clipped versus sutured hepatic artery, portal vein, and bile duct anastomoses

Attempts at improving anastomoses have included the development of stapling techniques. Our purpose was to evaluate arcuate-legged clipped versus standard sutured anastomoses of the hepatic artery (HA), portal vein (PV), and bile duct in a porcine liver transplantation model. Two groups of pigs were studied intraoperatively and 1 day after liver transplantation. A control group underwent sutured anastomosis of PV and HA with polypropylene and of bile duct with polydioxanone (n = 8). An experimental group underwent anastomoses with arcuate-legged clips (n = 8). We analyzed the time to perform anastomosis and flows before and at various time points after anastomosis. In addition, patency and histology of the anastomoses were evaluated 1 day after operation, including a fibrin-thrombosis score, medial injury, and inflammation score. Times to complete HA and PV anastomoses were not different between clipped and sutured groups. However, the time was shorter to complete bile duct anastomosis with clips than with sutures (6.3 +/- 1.1 minutes and 13.3 +/- 2.0 minutes, respectively). Flows through HA anastomoses were not different between groups, but flow through the PV was higher in clipped compared with sutured anastomosis (P = 0.06). Patency was 100 per cent with no leaks for all three anastomoses in both groups. Histologic data were similar between vascular anastomotic groups. Sutured bile duct anastomoses revealed mild smooth muscle injury in 75 per cent whereas clipped bile duct anastomoses displayed no smooth muscle injury. We conclude that arcuate-legged clipped anastomosis represents a viable option to sutured anastomoses of the PV, HA, and bile duct anastomoses. Bile duct anastomoses were completed in less than half the time and with less tissue damage documented histologically.

The effect of nutritional and hormonal supplementation on protein synthesis immediately after liver transplantation

We have previously shown that immediately after liver transplantation (LT) the porcine recipient exhibits elevated plasma glucagon, increased fractional synthetic rate (FSR) of fibrinogen, and decreased FSR of fixed or structural liver proteins. The purpose of this study was to evaluate the effect of nutritional and hormonal supplementation on these observations 24 h after LT. Two groups of nine pigs were studied 1 day after LT using radioisotopic and arteriovenous difference techniques. A control group underwent LT with saline infusion and a supplemented group underwent LT with infusion of glucose, amino acids (6 and 1.06 mg/kg. min, respectively), and intraportal insulin (0.6 mU/kg. min) and glucagon (1.3 ng/kg. min). Primed constant infusions of [3H]leucine were used to determine leucine flux, an estimate of whole body protein breakdown, and fractional synthetic rates (FSR). The following changes were noted with supplementation: elevated plasma insulin (6 +/- 1 versus 29 +/- 4 microU/ml, control versus supplemented, respectively, P < 0.05), decreased glucagon to normal levels (323 +/- 65 versus 102 +/- 12 pg/ml, P < 0.05), decreased fibrinogen FSR (108 +/- 15 versus 70 +/- 6%/day, P < 0.025), and increased fixed liver protein FSR (8 +/- 1 versus 13 +/- 2%/day, P < 0.05, respectively). Albumin FSR was unaltered by supplementation (8 +/- 2 versus 6 +/- 1%/day, respectively). Nutritional and hormonal supplementation immediately after LT restored the measured protein synthesis in the allograft to near normal levels 1 day after transplantation.

Hepatocellular carcinoma outcomes based on indicated treatment strategy

Hepatocellular carcinoma (HCC) in Western populations historically has been associated with poor survival. In this study, we conducted a 7-year retrospective analysis of patients evaluated at our institution with HCC to determine the effects of newer treatment strategies on outcome. During the period of study, 117 patients [86 (74%) male; mean age, 59 years (range, 16-85)] were evaluated with treatment as follows: surgical resection in 22 (19%), chemoembolization with or without systemic chemotherapy in 40 (35%), systemic treatment alone in 16 (13%), orthotopic liver transplantation in 8 (7%), and supportive care only in 31 (26%). Sixty-nine patients (59%) had documented cirrhosis, with hepatitis C being the most common cause in 27 of 69 (39%). In patients receiving no treatment, median survival was just under 3 months, with only two 1-year survivors. Patients with orthotopic liver transplantation had 1-, 2-, and 3-year survival rates of 87, 87, and 58 per cent compared with 69, 52, and 43 per cent in surgically resected patients. Survival after chemoembolization was 35, 20, and 11 per cent at 1, 2, and 3 years, whereas survival after systemic chemotherapy was 30 and 15 per cent at 1 and 2 years, respectively. One-year survival was improved in noncirrhotic patients compared with cirrhotics (47% vs 29%; P < 0.05) but was no different in patients younger than 55 years compared with older patients (38% vs 38%). When possible, surgical treatment strategies offer superior survival.

Establishment and characterization of primary gallbladder epithelial cell cultures in the prairie dog

BACKGROUND

The prairie dog has become the established animal gallstone model. This species has a unique propensity to form cholesterol gallstones in response to dietary manipulations. The development of a reliable gallbladder cell culture technique is critical for understanding pathogenic mechanisms of gallstone formation.

MATERIALS AND METHODS

Prairie dogs underwent laparotomy and cholecystectomy, followed by initiation of cell cultures. [3H]Thymidine incorporation was used to assess cell growth, and cell lines were assessed using routine histochemical and immunohistochemical staining.

RESULTS

Cell yields from prairie dog gallbladders were 4-8 x 10(6) viable cells per animal with viability ranging from 80 to 95%. When plated at 5 x 10(5) cells/cm2, cell clusters, visible within 24 h, coalesced into confluent monolayers within 3-5 days. Cultures remained viable for 6-8 weeks and could be passed for three to four subcultures. Immunohistochemical staining demonstrated a high degree of epithelial purity with immunopositivity for AE1/AE3, and cytokeratin, with no vimentin positivity (mesenchymal antigen). Intracytoplasmic vacuoles demonstrated positive staining for Alcian blue, periodic acid-Schiff, and mucicarmine and an anti-gallbladder mucin antibody confirmed the presence of the glycoprotein mucin.

CONCLUSIONS

This study demonstrates a reliable method for initiation and maintenance of prairie dog gallbladder epithelial cell cultures with a high degree of purity. This technique should allow further studies into the pathogenesis of cholesterol gallstones in this model.

Surgical clips: a cause of late recurrent gallstones

The formation of gallstones around surgical clips after cholecystectomy is a rare complication, with only seven reported cases in the English literature since its initial description in 1979. Three other cases report clip migration into the common bile duct and obstruction. We report a recent experience with "clip cholelithiasis." A 78-year-old female, 16 years following cholecystectomy, presented with a several-month history of colicky abdominal pain worsened by meals, and a 1 week history of jaundice, anorexia, nausea, and vomiting. An abdominal ultrasound demonstrated dilatation of the biliary tree without visible choledocholithiasis. Endoscopic retrograde cholangiopancreatography demonstrated a 1.5-cm radiolucent stone in the common bile duct containing a central surgical clip. She was successfully treated with endoscopic sphincterotomy and stone retrieval. The first report of clip cholelithiasis occurred in 1979. Six additional cases have been reported as well as three cases of clip migration without stone formation into the common bile duct. The incidence of clip cholelithiasis may increase in frequency with the increased use of metallic clips during laparoscopic cholecystectomy. The occurrence of cholelithiasis around inert metals is rare and may be prevented using absorbable clips; however, stone formation is also reported around absorbable materials.

Vanderbilt experience with cryosurgery for 25 advanced hepatic tumors

There are reports that suggest cryosurgical techniques may be a useful adjunct or even a viable alternative to surgical resection for hepatobiliary malignancies. Our objective was to evaluate the clinical results following cryoablation in conjunction with surgical resection for advanced hepatic tumors. Cryosurgical techniques were used in 25 consecutive patients with advanced liver tumors (1) to achieve a > 1-cm tumor-free margin when standard surgical margins were close, (2) to manage multiple tumor nodules with or without standard surgical resection, or (3) to increase chemotherapy response rates in conjunction with hepatic arterial portocath placement. In these 25 patients cryoablation was applied to 44 of 91 lesions--independently in four patients and in combination with hepatic resection in 21 patients. Cryoablation was used in seven patients because of close surgical margins. In 18 patients cryosurgery was used for complete lesion ablation. In 14 of the 18 patients cryosurgery and resection were used for different lesions; in four cryosurgery alone was used. Transient changes in hepatic enzymes, PT, PTT, and platelets were at maximum on postoperative days 1 to 3. Surgical mortality and morbidity rates were 4% and 68% respectively. Coagulation abnormalities were common; at least 30% reduction in platelets occurred in all patients and a > 50% reduction occurred in 15 of 25 (60%). Sixteen patients had a PT > 15 sec and five of these 16 also had platelet count < 50,000. Associated complications included one wound hematoma, one GI hemorrhage, one intracranial hemorrhage, and one hepatic hemorrhage from the cryosurgical site. 96%, 66%, 49%, 35%, and 20% of patients were surviving respectively at 6, 12, 18, 24, and 36 months. This report helps define the risks and results of cryosurgical ablation in conjunction with surgical resection for very advanced hepatobiliary tumors. Management of lesions contiguous to major blood vessels can include the Pringle maneuver or total hepatic vascular isolation. Cryoablation can be applied carefully as a complement to resection to achieve total tumor ablation in selected otherwise unresectable patients.

Management of bronchobiliary fistula as a late complication of hepatic resection

Bronchobiliary fistula is an uncommon but remarkable complication after hepatic resection. The case reported illustrates the clinical presentation and preferred initial management of these fistulae. A 61-year-old white male underwent two wedge resections for colorectal metastases to the liver with removal of a portion of the right diaphragm. Four years later, he developed obstructive jaundice secondary to tumor recurrence in the porta hepatis, which required endoscopic stent placement, radiation, and chemotherapy. Almost 2 years later, he developed frank biliptysis. Percutaneous transhepatic cholangiography (PTC) revealed occlusion of the common hepatic duct stent and a bronchobiliary fistula. With adequate reestablishment of common duct drainage, the patient rapidly improved and was discharged free of symptoms. Bronchobiliary fistulae are rare complications of hepatic resection that can present from days to years after operation. Endoscopic retrograde cholangiopancreatography and PTC are the diagnostic studies of choice and offer the possibility of therapeutic intervention. Although large series in the literature emphasize the surgical management of bronchobiliary fistulae, the reoperative procedures tend to be complicated, with a significant morbidity and mortality. Nonsurgical interventions via endoscopic retrograde cholangiopancreatography or PTC are more recently notably successful when resolution of a distal biliary obstruction is accomplished. Only after aggressive attempts at nonoperative, interventional techniques have failed should operative approaches be entertained.