Fecal metabolite profiling identifies liver transplant recipients at risk for postoperative infection

Metabolites produced by the intestinal microbiome modulate mucosal immune defenses and optimize epithelial barrier function. Intestinal dysbiosis, including loss of intestinal microbiome diversity and expansion of antibiotic-resistant pathobionts, is accompanied by changes in fecal metabolite concentrations and increased incidence of systemic infection. Laboratory tests that quantify intestinal dysbiosis, however, have yet to be incorporated into clinical practice. We quantified fecal metabolites in 107 patients undergoing liver transplantation (LT) and correlated these with fecal microbiome compositions, pathobiont expansion, and postoperative infections. Consistent with experimental studies implicating microbiome-derived metabolites with host-mediated antimicrobial defenses, reduced fecal concentrations of short- and branched-chain fatty acids, secondary bile acids, and tryptophan metabolites correlate with compositional microbiome dysbiosis in LT patients and the relative risk of postoperative infection. Our findings demonstrate that fecal metabolite profiling can identify LT patients at increased risk of postoperative infection and may provide guideposts for microbiome-targeted therapies.

Assessing Liver Viability: Insights From Mitochondrial Bioenergetics in Ischemia-Reperfusion Injury

Orthotopic liver transplantation remains the definitive treatment for patients with end-stage liver disease. Unfortunately, the increasing demand for donor livers and the limited supply of viable organs have both led to a critical need for innovative strategies to expand the pool of transplantable organs. The mitochondrion, central to hepatic cellular function, plays a pivotal role in hepatic ischemic injury, with impaired mitochondrial function and oxidative stress leading to cell death. Mitochondrial protection strategies have shown promise in mitigating IRI and resuscitating marginal organs for transplant. Machine perfusion (MP) has been proven a valuable tool for reviving marginal organs with very promising results. Evaluation of liver viability during perfusion traditionally relies on parameters including lactate clearance, bile production, and transaminase levels. Nevertheless, the quest for more comprehensive and universally applicable viability markers persists. Normothermic regional perfusion has gained robust attention, offering extended recovery time for organs from donation after cardiac death donors. This approach has shown remarkable success in improving organ quality and reducing ischemic injury using the body's physiological conditions. The current challenge lies in the absence of a reliable assessment tool for predicting graft viability and post-transplant outcomes. To address this, exploring insights from mitochondrial function in the context of ischemia-reperfusion injury could offer a promising path toward better patient outcomes and graft longevity. Indeed, hypoxia-induced mitochondrial injury may serve as a surrogate marker of organ viability following oxygenated resuscitation techniques in the future.

The benefit of liver transplant beyond Milan criteria: An analysis using the National Cancer Database

BACKGROUND

Published studies examining the efficacy of liver transplantation in patients presenting with hepatocellular cancer beyond the traditional Milan criteria for liver transplantation have primarily been single institution series with limited ability to compare outcomes to alternative methods of management.

METHODS

We queried the National Cancer Database to identify patients presenting between 2004 and 2016 with histologically confirmed clinical stage III and IVA hepatocellular cancer. Multivariable regression was used to identify factors associated with liver transplantation. Patients undergoing liver transplantation were 1:1 propensity score-matched for age, demographics, comorbid disease, clinical stage, and histologic resection margin to those undergoing surgical resection. The Kaplan-Meier method was used to compare overall survival profiles for matched cohorts.

RESULTS

Seven hundred and ninety-two patients met inclusion criteria-590 (74.5%) underwent surgical resection and 202 (25.5%) liver transplantation. On adjusted analysis, patients undergoing liver transplantation were less likely to have advanced age (>60 years; odds ratio 0.39, 95% confidence interval [0.21-0.71]) and to be of Black race (odds ratio 0.42, 95% confidence interval [0.23-0.73]) or Asian (odds ratio 0.25, 95% confidence interval [0.11-0.53]) ethnicity but were more likely to have advanced (Charlson score >2) comorbidity scores, (odds ratio 2.48, 95% confidence interval [1.58-3.90]) and more likely to have private health insurance (odds ratio 4.17, 95% confidence interval [1.31-18.66]) than those undergoing surgical resection. On Kaplan-Meier analysis of matched cohorts, patients undergoing liver transplantation demonstrated significantly better rates of 5-year overall survival (65.3% vs 26.3%, P < .0001) and longer median overall survival times than those undergoing resection (53.1 ± 2.78 vs 26.9 ± 1.20 months, P < .0001).

CONCLUSION

Liver transplantation offers the potential to be an effective treatment modality in select patients presenting with stage III and IVA hepatocellular cancer.

Combined heart-liver-kidney transplant: The university of chicago medicine experience

Until recently, combined heart-liver-kidney transplantation was considered too complex or too high-risk an option for patients with end-stage heart failure who present with advanced liver and kidney failure as well. The objective of this paper is to present our institution's best practices for successfully executing this highly challenging operation. At our institution, referral patterns are most often initiated through the cardiac team. Determinants of successful outcomes include diligent multidisciplinary patient selection, detailed perioperative planning, and choreographed care transition and coordination among all transplant teams. The surgery proceeds in three distinct phases with three different teams, linked seamlessly in planned handoffs. The selection and perioperative care are executed with determined collaboration of all of the invested care teams. This article is protected by copyright. All rights reserved.

Intrahepatic cholangiocarcinoma: Is there a role for liver transplantation?

BACKGROUND

Liver transplantation offers a potential for curative-intent treatment in patients presenting with non-metastatic intrahepatic cholangiocarcinoma that is not amenable to partial hepatectomy. There is little empiric evidence evaluating the efficacy of liver transplantation in patients with intrahepatic cholangiocarcinoma.

METHODS

We queried the National Cancer Database to identify patients presenting with histologically confirmed clinical stage I to III intrahepatic cholangiocarcinoma between 2004 and 2016. Propensity scoring was used to develop matched cohorts of patients undergoing treatment with liver transplantation, surgical resection, or chemotherapy alone. Kaplan Meier methods were used to compare rates of overall survival.

RESULTS

One thousand four hundred and eleven patients met inclusion criteria. Of these, 66 (4.7%) underwent liver transplantation, 461 (32.7%) underwent surgical resection, and 884 (62.6%) were treated with chemotherapy alone. On adjusted analysis, patients undergoing liver transplantation were more likely to be male (odds ratio 4.35, 95% confidence interval [0.12, 0.42]), have a Charlson Comorbidity Score ≥2 (odds ratio 3.11, 95% confidence interval [1.44, 6.57]), and to receive both neoadjuvant (odds ratio 2.78, 95% confidence interval [1.36,5.75], and adjuvant (odds ratio 1.94, 95% confidence interval [0.97, 3.87]) systemic therapy than those undergoing resection. On Kaplan Meier analysis, patients undergoing liver transplantation demonstrated rates of 5-year overall survival (36.1% vs 34.7%, P = .53) that were statistically identical to those for stage-matched and margin-matched patients undergoing resection but significantly better than those for stage-matched patients treated with systemic therapy alone (36.1% vs 5.3%, P < .0001).

CONCLUSION

Patients undergoing liver transplantation for intrahepatic cholangiocarcinoma demonstrate overall survival profiles similar to stage-matched and margin-matched patients undergoing surgical resection. Liver transplantation is an effective treatment modality in select patients presenting with localized intrahepatic cholangiocarcinoma.

Evolving Impact of COVID-19 on Transplant Center Practices and Policies in the United States

In our first survey of transplant centers in March 2020, >75% of kidney and liver programs were either suspended or operating under restrictions. To safely resume transplantation, we must understand the evolving impact of COVID-19 on transplant recipients and center-level practices. We therefore conducted a six-week follow-up survey May 7-15, 2020, and linked responses to the COVID-19 incidence map, with a response rate of 84%. Suspension of live donor transplantation decreased from 72% in March to 30% in May for kidneys and from 68% to 52% for livers. Restrictions/suspension of deceased donor transplantation decreased from 84% to 58% for kidneys and from 73% to 42% for livers. Resuming transplantation at normal capacity was envisioned by 83% of programs by August 2020. Exclusively using local recovery teams for deceased donor procurement was reported by 28%. Respondents reported caring for a total of 1166 COVID-19-positive transplant recipients; 25% were critically ill. Telemedicine challenges were reported by 81%. There was a lack of consensus regarding management of potential living donors or candidates with SARS-CoV-2. Our findings demonstrate persistent heterogeneity in center-level response to COVID-19 even as transplant activity resumes, making ongoing national data collection and real-time analysis critical to inform best practices.

Liver Transplantation Today: Where We Are Now and Where We Are Going

Liver transplantation was made a reality through the bravery, innovation, and persistence of Dr. Thomas Starzl. His death in 2017, at the age of 90, makes us pause to consider how far the field has come since its inception by this remarkable pioneer. It also is an opportunity to evaluate the continued novel innovations which contribute to the growth and potential for liver transplantation in the future. The liver transplant community in 2017 continued to be most significantly challenged by an overwhelming disparity between the need for liver transplant and the shortage of donor organs. The many ways in which this critical shortage are being addressed are examined in this article. The continued debate about equitable and efficacious organ allocation, "the liver wars," has dominated much of the recent past, while efforts to optimize current organ availability have also been aggressively pursued. Efforts to optimize the use of marginal and expanded criteria organs have escalated in recent years and have been accompanied by rigorous scientific evaluation. The ongoing opioid epidemic, combined with the approval and availability of highly effective hepatitis C treatment options, has allowed the increased use of HCV positive organs in HCV positive and negative recipients. Machine perfusion, both cold and warm, has moved solidly into the liver transplant world potentiating optimization of marginal donors and also offering potential modulation of liver grafts (ie, gene therapy, stem cell therapy, and defatting). Finally, pharmacological and mechanical interventions in DCD procurement techniques have contributed to improved outcomes in DCD transplants. All of these are explored in this article as a tribute to innovative spirit of Dr. Starzl and his continued impact on liver transplant today.

Genome-wide association study across European and African American ancestries identifies a SNP in DNMT3B contributing to nicotine dependence

Cigarette smoking is a leading cause of preventable mortality worldwide. Nicotine dependence, which reduces the likelihood of quitting smoking, is a heritable trait with firmly established associations with sequence variants in nicotine acetylcholine receptor genes and at other loci. To search for additional loci, we conducted a genome-wide association study (GWAS) meta-analysis of nicotine dependence, totaling 38,602 smokers (28,677 Europeans/European Americans and 9925 African Americans) across 15 studies. In this largest-ever GWAS meta-analysis for nicotine dependence and the largest-ever cross-ancestry GWAS meta-analysis for any smoking phenotype, we reconfirmed the well-known CHRNA5-CHRNA3-CHRNB4 genes and further yielded a novel association in the DNA methyltransferase gene DNMT3B. The intronic DNMT3B rs910083-C allele (frequency=44-77%) was associated with increased risk of nicotine dependence at P=3.7 × 10-8 (odds ratio (OR)=1.06 and 95% confidence interval (CI)=1.04-1.07 for severe vs mild dependence). The association was independently confirmed in the UK Biobank (N=48,931) using heavy vs never smoking as a proxy phenotype (P=3.6 × 10-4, OR=1.05, and 95% CI=1.02-1.08). Rs910083-C is also associated with increased risk of squamous cell lung carcinoma in the International Lung Cancer Consortium (N=60,586, meta-analysis P=0.0095, OR=1.05, and 95% CI=1.01-1.09). Moreover, rs910083-C was implicated as a cis-methylation quantitative trait locus (QTL) variant associated with higher DNMT3B methylation in fetal brain (N=166, P=2.3 × 10-26) and a cis-expression QTL variant associated with higher DNMT3B expression in adult cerebellum from the Genotype-Tissue Expression project (N=103, P=3.0 × 10-6) and the independent Brain eQTL Almanac (N=134, P=0.028). This novel DNMT3B cis-acting QTL variant highlights the importance of genetically influenced regulation in brain on the risks of nicotine dependence, heavy smoking and consequent lung cancer.

Liver transplant offers a survival benefit over margin negative resection in patients with small unifocal hepatocellular carcinoma and preserved liver function

BACKGROUND

Studies comparing orthotopic liver transplantation to margin negative resection for patients with small unifocal hepatocellular carcinoma have not controlled for degree of cirrhosis.

METHODS

The National Cancer Database was used to identify patients with preserved liver function (Model for End-stage Liver Disease score ≤12) who underwent orthotopic liver transplantation or margin negative resection for American Joint Committee on Cancer stage I hepatocellular carcinoma lesions <3 cm between 2010 and 2013. Multivariable and Cox regression adjusting for age, demographics, comorbid disease burden, Model for End-stage Liver Disease score, tumor size, and operation were used to compare overall survival between cohorts.

RESULTS

In the study, 241 (53%) patients underwent orthotopic liver transplantation. In addition, 219 (47%) underwent margin negative resection. On multivariable regression, patients having a Charlson comorbidity score ≥2 were more likely to undergo orthotopic liver transplantation, (odds ratio 1.94, P=.03). African American patients (odds ratio 0.44, P=.02), and patients of advanced age (odds ratio 0.92, P<.001) were more likely to undergo margin negative resection. Patients undergoing orthotopic liver transplantation had longer overall survival than those undergoing margin negative resection (median OS not reached versus 67.6 months, P<.001). Multivariable Cox regression identified surgical procedure as the only independent determinant of survival with margin negative resection conferring a nearly 3-fold increased risk of death (hazard ratio 2.86, P<.001).

CONCLUSION

Orthotopic liver transplantation offers a survival advantage relative to margin negative resection for patients with small unifocal hepatocellular carcinoma and preserved liver function.

Nicotine dependence is associated with functional variation in FMO3, an enzyme that metabolizes nicotine in the brain

A common haplotype of the flavin-containing monooxygenase gene FMO3 is associated with aberrant mRNA splicing, a twofold reduction in in vivo nicotine N-oxidation and reduced nicotine dependence. Tobacco remains the largest cause of preventable mortality worldwide. CYP2A6, the primary hepatic nicotine metabolism gene, is robustly associated with cigarette consumption but other enzymes contribute to nicotine metabolism. We determined the effects of common variants in FMO3 on plasma levels of nicotine-N-oxide in 170 European Americans administered deuterated nicotine. The polymorphism rs2266780 (E308G) was associated with N-oxidation of both orally administered and ad libitum smoked nicotine (P⩽3.3 × 10^-5 controlling for CYP2A6 genotype). In vitro, the FMO3 G308 variant was not associated with reduced activity, but rs2266780 was strongly associated with aberrant FMO3 mRNA splicing in both liver and brain (P⩽6.5 × 10^-9). Surprisingly, in treatment-seeking European American smokers (n=1558) this allele was associated with reduced nicotine dependence, specifically with a longer time to first cigarette (P=9.0 × 10^-4), but not with reduced cigarette consumption. As N-oxidation accounts for only a small percentage of hepatic nicotine metabolism we hypothesized that FMO3 genotype affects nicotine metabolism in the brain (unlike CYP2A6, FMO3 is expressed in human brain) or that nicotine-N-oxide itself has pharmacological activity. We demonstrate for the first time nicotine N-oxidation in human brain, mediated by FMO3 and FMO1, and show that nicotine-N-oxide modulates human α4β2 nicotinic receptor activity in vitro. These results indicate possible mechanisms for associations between FMO3 genotype and smoking behaviors, and suggest nicotine N-oxidation as a novel target to enhance smoking cessation.

Biliary reconstructive techniques and associated anatomic variants in adult living donor liver transplantations: The adult-to-adult living donor liver transplantation cohort study experience

Living donor liver transplantation (LDLT) is a technically demanding endeavor, requiring command of the complex anatomy of partial liver grafts. We examined the influence of anatomic variation and reconstruction techniques on surgical outcomes and graft survival in the 9-center Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Data from 272 adult LDLT recipients (2011-2015) included details on anatomic characteristics and types of intraoperative biliary reconstruction. Associations were tested between reconstruction technique and complications, which included first biliary complication (BC; leak, stricture, or biloma) and first vascular complication (VC; hepatic artery thrombosis [HAT] or portal vein thrombosis [PVT]). Time to patient death, graft failure, and complications were estimated using Kaplan-Meier curves and tested with log-rank tests. Median posttransplant follow-up was 1.2 years. Associations were found between the type of biliary reconstruction and the incidence of VC (P = 0.03) and BC (P = 0.05). Recipients with Roux-en-Y hepaticojejunostomy had the highest probability of VC. Recipients with biliary reconstruction involving the use of high biliary radicals on the recipient duct had the highest likelihood of developing BC (56% by 1 year) compared with duct-to-duct (42% by 1 year). In conclusion, the varied surgical approaches in the A2ALL centers offer a novel opportunity to compare disparate LDLT approaches. The choice to use higher biliary radicals on the recipient duct for reconstruction was associated with more BC, possibly secondary to devascularization and ischemia. The use of Roux-en-Y biliary reconstruction was associated with VCs (HAT and PVT). These results can be used to guide biliary reconstruction decisions in the setting of anatomic variants and inform further improvements in LDLT reconstructions. Ultimately, this information may contribute to a lower incidence of technical complications after LDLT. Liver Transplantation 23 1519-1530 2017 AASLD.

Genome-wide meta-analysis reveals common splice site acceptor variant in CHRNA4 associated with nicotine dependence

We conducted a 1000 Genomes-imputed genome-wide association study (GWAS) meta-analysis for nicotine dependence, defined by the Fagerström Test for Nicotine Dependence in 17 074 ever smokers from five European-ancestry samples. We followed up novel variants in 7469 ever smokers from five independent European-ancestry samples. We identified genome-wide significant association in the alpha-4 nicotinic receptor subunit (CHRNA4) gene on chromosome 20q13: lowest P=8.0 × 10(-9) across all the samples for rs2273500-C (frequency=0.15; odds ratio=1.12 and 95% confidence interval=1.08-1.17 for severe vs mild dependence). rs2273500-C, a splice site acceptor variant resulting in an alternate CHRNA4 transcript predicted to be targeted for nonsense-mediated decay, was associated with decreased CHRNA4 expression in physiologically normal human brains (lowest P=7.3 × 10(-4)). Importantly, rs2273500-C was associated with increased lung cancer risk (N=28 998, odds ratio=1.06 and 95% confidence interval=1.00-1.12), likely through its effect on smoking, as rs2273500-C was no longer associated with lung cancer after adjustment for smoking. Using criteria for smoking behavior that encompass more than the single 'cigarettes per day' item, we identified a common CHRNA4 variant with important regulatory properties that contributes to nicotine dependence and smoking-related consequences.

Organ Procurement

Improvements in immunosuppression, organ preservation, surgical technique, and recipient management have led to the widespread adoption of transplantation as a viable therapeutic option for end-stage organ disease. Consequently, more patients than ever are benefiting from organ transplantation. Unfortunately, the rate of organ donation has not kept pace with the increase in the number of recipients awaiting transplantation. The relative shortage of organs has necessitated an increasing reliance on creative strategies aimed at broadening or expanding the limits of the donor pool. For instance, organs now are frequently obtained from so-called extended-criteria donors (i.e., donors who are elderly or who have significant comorbid conditions) or from non-heart-beating donors. A particularly important strategy for alleviating the organ shortage has been the broader application of living donor transplantation. The authors outline the current state of organ procurement from both cadaveric and living donors, including donor evaluation, perioperative management, and the various donor procedures. This review contains 14 figures, 1 table, and 63 references.

Changes in liver and spleen volumes after living liver donation: a report from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL)

Previous reports have drawn attention to persistently decreased platelet counts among liver donors. We hypothesized an etiologic association between altered platelet counts and postdonation splenomegaly and sought to explore this relationship. This study analyzed de-identified computed tomography/magnetic resonance scans of 388 donors from 9 Adult-to-Adult Living Donor Liver Transplantation Cohort Study centers read at a central computational image analysis laboratory. Resulting liver and spleen volumes were correlated with time-matched clinical laboratory values. Predonation liver volumes varied 2-fold in healthy subjects, even when they were normalized by the body surface area (BSA; range = 522-1887 cc/m(2) , n = 346). At month 3 (M3), postdonation liver volumes were, on average, 79% of predonation volumes [interquartile range (IQR) = 73%-86%, n = 165] and approached 88% at year 1 (Y1; IQR = 80%-93%, n = 75). The mean spleen volume before donation was 245 cc (n = 346). Spleen volumes greater than 100% of the predonation volume occurred in 92% of donors at M3 (n = 165) and in 88% at Y1 after donation (n = 75). We sought to develop a standard spleen volume (SSV) model to predict normal spleen volumes in donors before donation and found that decreased platelet counts, a younger age, a higher predonation liver volume, higher hemoglobin levels, and a higher BSA predicted a larger spleen volume (n = 344, R(2)  = 0.52). When this was applied to postdonation values, some large volumes were underpredicted by the SSV model. Models developed on the basis of the reduced sample of postdonation volumes yielded smaller underpredictions. These findings confirm previous observations of thrombocytopenia being associated with splenomegaly after donation. The results of the SSV model suggest that the biology of this phenomenon is complex. This merits further long-term mechanistic studies of liver donors with an investigation of the role of other factors such as thrombopoietin and exposure to viral infections to better understand the evolution of the spleen volume after liver donation.

Five population-based interventions for smoking cessation: a MOST trial

Little is known about the relative, additive, and interactive effects of different population-based treatments for smoking cessation. The goal of this study was to evaluate the main and interactive effects of five different smoking interventions. Using the multiphase optimization strategy (MOST), 1,034 smokers who entered a Web site for smokers (smokefree.gov) were randomly assigned to the "on" and "off" conditions of five smoking cessation interventions: the National Cancer Institute's (NCI) Web site (www.smokefree.gov vs a "lite" Web site), telephone quitline counseling (vs none), a smoking cessation brochure (vs a lite brochure), motivational e-mail messages (vs none), and mini-lozenge nicotine replacement therapy (NRT vs none). Analyses showed that the NCI Web site and NRT both increased abstinence; however, the former increased abstinence significantly only when it was not used with the e-mail messaging intervention (messaging decreased Web site use). The other interventions showed little evidence of effectiveness. There was evidence that mailed nicotine mini-lozenges and the NCI Web site (www.smokefree.gov) provide benefit as population-based smoking interventions.

Liver regeneration after living donor transplantation: adult-to-adult living donor liver transplantation cohort study

Adult-to-adult living donors and recipients were studied to characterize patterns of liver growth and identify associated factors in a multicenter study. Three hundred and fifty donors and 353 recipients in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL) receiving transplants between March 2003 and February 2010 were included. Potential predictors of 3-month liver volume included total and standard liver volumes (TLV and SLV), Model for End-Stage Liver Disease (MELD) score (in recipients), the remnant and graft size, remnant-to-donor and graft-to-recipient weight ratios (RDWR and GRWR), remnant/TLV, and graft/SLV. Among donors, 3-month absolute growth was 676 ± 251 g (mean ± SD), and percentage reconstitution was 80% ± 13%. Among recipients, GRWR was 1.3% ± 0.4% (8 < 0.8%). Graft weight was 60% ± 13% of SLV. Three-month absolute growth was 549 ± 267 g, and percentage reconstitution was 93% ± 18%. Predictors of greater 3-month liver volume included larger patient size (donors and recipients), larger graft volume (recipients), and larger TLV (donors). Donors with the smallest remnant/TLV ratios had larger than expected growth but also had higher postoperative bilirubin and international normalized ratio at 7 and 30 days. In a combined donor-recipient analysis, donors had smaller 3-month liver volumes than recipients adjusted for patient size, remnant or graft volume, and TLV or SLV (P = 0.004). Recipient graft failure in the first 90 days was predicted by poor graft function at day 7 (HR = 4.50, P = 0.001) but not by GRWR or graft fraction (P > 0.90 for each). Both donors and recipients had rapid yet incomplete restoration of tissue mass in the first 3 months, and this confirmed previous reports. Recipients achieved a greater percentage of expected total volume. Patient size and recipient graft volume significantly influenced 3-month volumes. Importantly, donor liver volume is a critical predictor of the rate of regeneration, and donor remnant fraction affects postresection function. Liver Transpl 21:79-88, 2015. © 2014 AASLD.

Plasma protein biomarkers enhance the clinical prediction of kidney injury recovery in patients undergoing liver transplantation

Biomarkers predictive of recovery from acute kidney injury (AKI) after liver transplantation (LT) could enhance decision algorithms regarding the need for liver-kidney transplantation or renal sparing regimens. Multianalyte plasma/urine kidney injury protein panels were performed immediately before and 1 month post-LT in an initial test group divided by reversible pre-LT AKI (rAKI = post-LT renal recovery) versus no AKI (nAKI). This was followed by a larger validation set that included an additional group: irreversible pre-LT AKI (iAKI = no post-LT renal recovery). In the test group (n = 16), six pre-LT plasma (not urine) kidney injury proteins (osteopontin [OPN], neutrophil gelatinase-associated lipocalin, cystatin C, trefoil factor 3, tissue inhibitor of metalloproteinase [TIMP]-1, and β-2-microglobulin) were higher in rAKI versus nAKI (P < 0.05) and returned to normal values with renal recovery post-LT. In the validation set (n = 46), a number of proteins were significantly higher in both rAKI and iAKI versus nAKI. However, only pre-LT plasma OPN (P = 0.009) and TIMP-1 (P = 0.019) levels were significantly higher in rAKI versus iAKI. Logistic regression modeling was used to correlate the probability of post-LT rAKI, factoring in both pre-LT protein markers and clinical variables. A combined model including elevated OPN and TIMP-1 levels, age <57, and absence of diabetes had the highest area under the curve of 0.82, compared to protein-only and clinical variable-only models.

CONCLUSION

These data suggest that plasma protein profiles might improve the prediction of pre-LT kidney injury recovery after LT. However, multicenter, prospective studies are needed to validate these findings and ultimately test the value of such protein panels in perioperative management and decision making.

Liver transplant recipient survival benefit with living donation in the model for endstage liver disease allocation era

Receipt of a living donor liver transplant (LDLT) has been associated with improved survival compared with waiting for a deceased donor liver transplant (DDLT). However, the survival benefit of liver transplant has been questioned for candidates with Model for Endstage Liver Disease (MELD) scores <15, and the survival advantage of LDLT has not been demonstrated during the MELD allocation era, especially for low MELD patients. Transplant candidates enrolled in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study after February 28, 2002 were followed for a median of 4.6 years. Starting at the time of presentation of the first potential living donor, mortality for LDLT recipients was compared to mortality for patients who remained on the waiting list or received DDLT (no LDLT group) according to categories of MELD score (<15 or ≥ 15) and diagnosis of hepatocellular carcinoma (HCC). Of 868 potential LDLT recipients (453 with MELD <15; 415 with MELD ≥ 15 at entry), 712 underwent transplantation (406 LDLT; 306 DDLT), 83 died without transplant, and 73 were alive without transplant at last follow-up. Overall, LDLT recipients had 56% lower mortality (hazard ratio [HR] = 0.44, 95% confidence interval [CI] 0.32-0.60; P < 0.0001). Among candidates without HCC, mortality benefit was seen both with MELD <15 (HR = 0.39; P = 0.0003) and MELD ≥ 15 (HR = 0.42; P = 0.0006). Among candidates with HCC, a benefit of LDLT was not seen for MELD <15 (HR = 0.82, P = 0.65) but was seen for MELD ≥ 15 (HR = 0.29, P = 0.043).

CONCLUSION

Across the range of MELD scores, patients without HCC derived a significant survival benefit when undergoing LDLT rather than waiting for DDLT in the MELD liver allocation era. Low MELD candidates with HCC may not benefit from LDLT.

Transplant renoportal vein conduit for complete mesenteric thrombosis: a case report

Portal vein thrombosis, which is present in up to one quarter of patients with end-stage liver disease, presents a technical challenge at the time of liver transplantation. Thromboendovenectomy when feasible has been advocated in these patients. However, in patients with complete mesenteric thrombosis where this technique is typically not successful, a number of alternative techniques have been attempted including caval transposition, portal arterialization, and multivisceral transplantation often with discouraging results. We present herein a single case where transplant renal vein outflow was used to provide portal vein inflow in a patient with complete mesenteric thrombosis undergoing simultaneous liver-kidney transplant.

Transplant Renoportal Vein Conduit for Complete Mesenteric Thrombosis: A Case Report

Portal vein thrombosis, which is present in up to one quarter of patients with end-stage liver disease, presents a technical challenge at the time of liver transplantation. Thromboendovenectomy when feasible has been advocated in these patients. However, in patients with complete mesenteric thrombosis where this technique is typically not successful, a number of alternative techniques have been attempted including caval transposition, portal arterialization, and multi-visceral transplantation often with discouraging results. We present herein a single case where transplant renal vein outflow was used to provide portal vein inflow in a patient with complete mesenteric thrombosis undergoing simultaneous liver-kidney transplant.

Chemoembolization for hepatocellular carcinoma: comprehensive imaging and survival analysis in a 172-patient cohort

PURPOSE

To determine comprehensive imaging and long-term survival outcome following chemoembolization for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

One hundred seventy-two patients with HCC treated with chemoembolization were studied retrospectively in an institutional review board approved protocol; this study was HIPAA compliant. Baseline laboratory and imaging characteristics were obtained. Clinical and laboratory toxicities following treatment were assessed. Imaging characteristics following chemoembolization were evaluated to determine response rates (size and necrosis) and time to progression (TTP). Survival from the time of first chemoembolization treatment was calculated. Subanalyses were performed by stratifying the population according to Child-Pugh, United Network for Organ Sharing, and Barcelona Clinic for Liver Cancer (BCLC) staging systems.

RESULTS

Cirrhosis was present in 157 patients (91%); portal hypertension was present in 139 patients (81%). Eleven patients (6%) had metastases at baseline. Portal vein thrombosis was present in 11 patients (6%). Fifty-five percent of patients experienced some form of toxicity following treatment; 21% developed grade 3 or 4 bilirubin toxicity. Post-chemoembolization response was seen in 31% and 64% of patients according to size and necrosis criteria, respectively. Median TTP was 7.9 months (95% confidence interval: 7.1, 9.4) but varied widely by stage. Median survival was significantly different between patients with BCLC stages A, B, and C disease (stage A, 40.0 months; B, 17.4 months; C, 6.3 months; P < .0001).

CONCLUSION

The determination of TTP and survival in patients with HCC is confounded by tumor biology and background cirrhosis; chemoembolization was shown to be a safe and effective therapy in patients with HCC.

Ureteral complications in the era of laparoscopic living donor nephrectomy: do we need to preserve the gonadal vein with the specimen?

BACKGROUND AND PURPOSE

The aim of this study was to analyze the ureteral complication rate in recipients transplanted with laparoscopically retrieved kidneys in our institution's 8-year experience when the gonal vein was not preserved with the specimen during the donor procedure.

PATIENTS AND METHODS

We reviewed the records of 800 consecutive laparoscopic donor nephrectomy patients. Donor sex, age, body mass index, warm ischemia time, hospital length of stay, donor and recipient serum creatinine levels, and incidence and type of complications including the incidence of ureteral complications were recorded.

RESULTS

Mean patient age was 39 +/- 10 years. Mean body mass index was 27 +/- 5. A total of 482 cases were treated purely laparoscopically. Of them, 318 were performed hand assisted. Seven hundred and ninety-three procedures were done on the left side and seven were done on the right side. The overall rate of intraoperative complications was 2.9%. The overall open conversion rate was 1.4%. The overall rate of postoperative complications was 3.9%. The postoperative day-7 serum creatinine values of the donors were 1.4 +/- 0.3 mg/dL. Mean creatinine in all patients at 1 week after transplantation was 1.5 +/- 0.2 mg/dL. We had one case of ureteral stricture in the recipients of laparoscopically procured kidneys without gonadal vein preservation technique among 800 patients.

CONCLUSION

Gonadal vein preservation with the entire specimen during laparoscopic donor nephrectomy procedure is not a necessary step to protect periureteral blood supply to prevent ureteral strictures.

The high-risk recipient: the Eighth Annual American Society of Transplant Surgeons' State-of-the-Art Winter Symposium

The evolution of organ transplantation has produced results so successful that many transplant programs commonly see recipients with medical risks, which in the past, would have prohibited transplantation. The Eighth Annual American Society of Transplant Surgeons State-of-the-Art Winter Symposium focused on the high-risk recipient. The assessment of risk has evolved over time, as transplantation has matured. The acceptance of risk associated with a given candidate today is often made in consideration of the relative value of the organ to other candidates, the regulatory environment, and philosophical notions of utility, equity, and fairness. In addition, transplant programs must balance outcomes, transplant volume, and the costs of organ transplantation, which are impacted by high-risk recipients. Discussion focused on various types of high-risk recipients, such as those with coronary artery disease, morbid obesity, and hepatitis C; strategies to reduce risk, such as down-staging of hepatocellular carcinoma and treatment of pulmonary hypertension; the development of alternatives to transplantation; and the degree to which risk can or should be used to define candidate selection. These approaches can modify the impact of recipient risk on transplant outcomes and permit transplantation to be applied successfully to a greater variety of patients.

Laparoscopy-assisted and open living donor right hepatectomy: a comparative study of outcomes

BACKGROUND

Minimally invasive liver surgery is a rapidly advancing field with demonstrated applicability to living donation. In this paper, we compare the safety and efficacy of laparoscopy-assisted donor right hepatectomy (LADRH) to open donor right hepatectomy (ODRH).

METHODS

We performed a retrospective, comparative analysis of 33 LADRH to the most recent 33 ODRH performed at our institution, evaluating donor complications, costs, and recipient outcomes.

RESULTS

Donor demographics including age, gender, body mass index (BMI), and vascular and biliary anomalies were comparable. Donor complication rates were equivalent for LADRH and ODRH. Donor operative times were shorter for LADRH (LADRH 265 minutes, ODRH 316; P < .001) even after adjusting for BMI. Blood loss and length of stay were comparable. Additionally, total hospitalization costs were equivalent (LADRH $1.11, ODRH $1.00; P = .19). Higher operative supply costs for LADRH were balanced by higher time-based operative costs for ODRH resulting in no significant differences in total operative costs. Finally, there were no differences in graft size, recipient patient or graft survival, or recipient vascular or biliary complications.

CONCLUSION

Our experience suggests that LADRH compares favorably with ODRH with equivalent safety, resource utilization, and effectiveness. We believe that LADRH provides potential physical and psychological benefits without an adverse effect on outcomes.

The impact of ischemic cholangiopathy in liver transplantation using donors after cardiac death: the untold story

BACKGROUND

Liver transplantation (LT) from donation after cardiac death (DCD) donors is increasingly being used to address organ shortages. Despite encouraging reports, standard survival metrics have overestimated the effectiveness of DCD livers. We examined the mode, kinetics, and predictors of organ failure and resource utilization to more fully characterize outcomes after DCD LT.

METHODS

We reviewed the outcomes for 32 DCD and 237 donation after brain death (DBD) LT recipients at our institution.

RESULTS

Recipients of DCD livers had a 2.1 times greater risk of graft failure, a 2.5 times greater risk of relisting, and a 3.2 times greater risk of retransplantation compared with DBD recipients. DCD recipients had a 31.6% higher incidence of biliary complications and a 35.8% higher incidence of ischemic cholangiopathy. Ischemic cholangiography was primarily implicated in the higher risk of graft failure observed after DCD LT. DCD recipients with ischemic cholangiography experienced more frequent rehospitalizations, longer hospital stays, and required more invasive biliary procedures.

CONCLUSION

Related to higher complication rates, DCD recipients necessitated greater resource utilization. This more granular data should be considered in the decision to promote DCD LT. Modification of liver allocation policy is necessary to address those disadvantaged by a failing DCD graft.

Radiation lobectomy: preliminary findings of hepatic volumetric response to lobar yttrium-90 radioembolization

PURPOSE

To describe volumetric changes of "radiation lobectomy," a manifestation of hepatic parenchymal response to lobar (90)Y microsphere radioembolization.

METHODS

Twenty patients exhibiting this phenomenon were identified. Pre- and posttreatment absolute right and left hepatic lobar volume (HLV), relative HLV (rHLV = HLV/total liver volume), and degree of lobar atrophy (DA) or hypertrophy (DH) (DA or DH = |posttreatment rHLV - pretreatment rHLV|) were determined. Laboratory toxicities, tumor response, and patient survival were also assessed.

RESULTS

Twenty patients with primary (HCC, n = 17; peripheral cholangiocarcinoma, n = 3) liver malignancies demonstrated findings of radiation lobectomy. Initial absolute right and left HLV was 955 cm(3) (range 644-1,842 cm(3), rHLV = 57%) and 719 cm(3) (range 328-1,387 cm(3), rHLV = 43%), respectively. Following (90)Y, absolute right HLV decreased to 460 cm(3) (range 185-948 cm(3), 52% reduction, rHLV = 31%, DA = 26%, P < 0.0001), while absolute left HLV increased to 1,004 cm(3) (range 560-1,558 cm(3), 40% increase, rHLV = 69%, DH = 26%, P < 0.0001). No grade 3 or 4 bilirubin toxicities were encountered. Tumor response ranged from 55% to 70% by size criteria. Forty-six percent 5-year survival was achieved in HCC patients.

CONCLUSIONS

Radiation lobectomy following (90)Y radioembolization of right lobe tumors manifests extensive contralateral lobar hypertrophy, high response rates, and prolonged survival. This phenomenon was noted in 6.4% (20/315) of the entire cohort and 19.8% (20/101) of patients with unilobar right lobe tumors. Further investigation is necessary to determine contributing factors that may predict this effect.

A novel technique for ureteral-ileocecal pouch anastomosis of a renal transplant in the left iliac fossa

Lower urinary tract reconstruction might be required to create a safe reservoir for urinary drainage before renal transplantation. We report the successful creation of a tension-free donor ureteral-ileocecal pouch anastomosis in a left-sided transplantation of a donor kidney, which necessitated tunneling the donor ureter through the mesentery of the sigmoid colon.

Proposed classification of complications after live donor nephrectomy

OBJECTIVES

A standardized classification for the potential complications of living donor nephrectomy is an essential step in establishing a construct for monitoring and reporting the outcomes of this procedure. It is also helpful in informing potential donors about the inherent risks of the donor operation as part of the informed choice process.

METHODS

We reviewed 600 laparoscopic live donor nephrectomies performed at our center. A modification of the Clavien classification system describing procedure-related complications was developed and used to grade the severity of all complications.

RESULTS

We observed 43 complications (7.2%) in our series of 600 patients. Grade 1 defines all events that, if left untreated, would have a spontaneous resolution or needed a simple bedside procedure (39.5%). Grade 2 complications differ from grade 1 in that they are potentially life-threatening and usually require some form of intervention, but do not result in ongoing disability. We subdivided grade 2 complications (55.8% in our study) into 2a, 2b, and 2c. The latter describes complications requiring open conversion of laparoscopic donor nephrectomy for patient treatment. Grade 3 complications are events with residual or lasting disability (4.7% in our review). Grade 4 events are those resulting in renal failure or death because of any complication (none occurred in our series).

CONCLUSIONS

A graded classification scheme for reporting the complications of donor nephrectomy may be useful for maintaining registry information on donor outcomes and when informing potential donors about the risks and benefits of this procedure.

Liver Graft Volume Estimation in 100 Living Donors: Measure Twice, Cut Once

Estimation of graft volume (GV) is critical in living donor liver transplantation. This study examines the accuracy of formula-derived GV estimates and compares them to both radiogically-derived estimates and actual measurements. We first compared formula-derived estimates of GV and compared them to actual volumes to provide estimates for both right lobe (RL) and left lateral segment (LLS) GV. We then applied these formulae to a validation cohort. Finally, we evaluated both formula-derived and radiologically-derived estimates by comparing them to actual GV measurements. There is a marginal concordance between formula-derived calculation and GV for RL donors, but the error ratio was lower than for radiologic estimates. In contrast, MRI measurements for LLS grafts demonstrated a lower error ratio than formula-derived estimation. Formula-derived estimates of GV should be routinely used in the initial screening of potential living donors as long as their limitations are appreciated.

Laparoscopic donor nephrectomy 1997 to 2003: lessons learned with 500 cases at a single institution

BACKGROUND

Laparoscopic live donor nephrectomy (LDN) is a less invasive alternative to traditional open nephrectomy that has several potential advantages. However, there have been few large series reports describing the complications of LDN and the details of their management.

METHODS

We performed a retrospective review of 500 LDNs performed at our center between October 1997 and September 2003. We evaluated preoperative donor characteristics, intraoperative parameters and complications, and postoperative recovery and complications. A modification of the Clavien classification was developed and used to grade the severity of all complications.

RESULTS

The overall rate of intraoperative complications was 2.8%. There were 9 open conversions (1.8%), of which 6 were in the first 100 cases. Six of the 9 open conversions were for management of complications; 3 were elective. Seven renovascular incidents (1.4%) all required open conversion except one. The overall rate of postoperative complications was 3.4%. Thirty of 500 patients in our LDN series experienced an intraoperative or procedure-related complication (6.0%). When graded by severity, 18 of 31 (58.1%) of all complications were grade 1, 11 of 31 (35.4%) grade 2, and 2 of 31 (6.5%) grade 3. Only 1 recipient experienced delayed graft function, and only 1 recipient had a urologic complication.

CONCLUSIONS

Our series supports the safety and efficacy of LDN with very low intraoperative complication and conversion rates. Most of the intraoperative complications can be managed laparoscopically. Readmissions are extremely rare (1.5%). Aberrant vascular anatomy and obesity are not contraindications to LDN, but they require experience. With careful surgical technique, delayed graft function and urologic complications in recipients can be avoided. A graded classification scheme for reporting complications of donor nephrectomy might be useful for maintaining registry information on donor outcomes and when informing potential donors about the risks and benefits of this procedure.

COMPARATIVE ANALYSIS OF LIVE LIVER DONATION RISK USING A COMPREHENSIVE GRADING SYSTEM FOR SEVERITY

We investigated whether right lobe (RL) liver donation is associated with a higher incidence or severity of donor complications than left lobe (LL) liver and left lateral segment (LLS) liver donations. We studied 80 living donors: 35 RL liver donors and 45 LL/LLS liver donors. A modification of the Clavien classification was used to grade the severity of complications. RL and LL/LLS liver donations had equivalent blood loss, readmission and reoperation rates, use of blood products, and lengths of stay in the intensive care unit and hospital. RL liver donors underwent longer surgeries and experienced more postoperative pain than LL/LLS liver donors. The overall rate of complications was 33%. There was a higher rate of complications in RL liver donors (51%) than LL/LLS liver donors (20%). When graded by severity, there were more grade 2 complications in RL liver donors than in LL/LLS liver donors. Our report confirms that RL liver donation is associated with higher morbidity than LL/LLS liver donation. When the complications are systematically graded by severity, there is a significant difference in Clavien grade 2 complications in RL liver donors.

Any further progress in smoking cessation treatment?

The release of the US Public Health Service's quantitative review of smoking treatments, Treating Tobacco Use and Dependence (TTUD; Fiore, Bailey, Cohen et al., 2000, AHRQ Publication, USDHHS), is a fitting occasion to revisit a question posed by Shiffman (1993, Journal of Consulting and Clinical Psychology, 61:718-722): has there been any recent progress in smoking cessation treatment? Using TTUD meta-analyses as a rough guide, we present an overview of current elements of clinical treatments (structure, content, and pharmacotherapy) with statistical claims to efficacy. We note characteristics of treatment, or treatment research, that may retard accumulation of critical knowledge, including the hegemony of multi-component treatments and a seeming disinterest in treatment process. Finally, we sketch avenues of potentially generative research that might foster new insights and improved treatments. It is concluded that not much has changed since Shiffman's (1993) review, and that his call for a rededication to basic research is still prudent but largely unanswered.

Gender and racial/ethnic differences in tobacco-dependence treatment: a commentary and research recommendations

The preparation of the Public Health Service Report, Treating Tobacco Use and Dependence, brought to light a substantial gap in the smoking cessation literature; there is little or no research evidence regarding the success of formal tobacco-dependence treatment specific to gender or racial/ethnic status. Of the 192 articles included in the meta-analyses of the evidence-based PHS Report, none included results based on racial/ethnic group and only four reported results by gender. This commentary identifies tobacco use as a problem that crosses gender and racial/ethnic boundaries, reviews reasons that the different genders or racial/ethnic groups might require different tobacco-dependence treatments, provides suggestive evidence that both gender and racial/ethnic status influence tobacco-dependence treatment efficacy, and recommends changes and directions for future clinical research that will address gender and racial/ethnicity effects.

Strike while the iron is hot: can stepped-care treatments resurrect relapsing smokers?

The efficacies of 2 group counseling step-up treatments for smoking cessation, cognitive-behavioral/skill training therapy (CBT) and motivational interviewing/supportive (MIS) therapy, were compared with brief intervention (BI) treatment in a sample of 677 smokers. Differential efficacy of the 2 step-up treatments was also tested in smokers at low and high risk for relapse (no smoking vs. any smoking during the first postquit week. respectively). All participants received 8 weeks of nicotine patch therapy. BI consisted of 3 brief individual cessation counseling sessions; CBT and MIS participants received BI treatment and 6 group counseling sessions. Neither CBT nor MIS treatment improved long-term abstinence rates relative to BI. Limited support was found for the hypothesis that high-risk smokers would benefit more from MIS than CBT. Other hypotheses were not supported.

Strike while the iron is hot: can stepped-care treatments resurrect relapsing smokers?

The efficacies of 2 group counseling step-up treatments for smoking cessation, cognitive-behavioral/skill training therapy (CBT) and motivational interviewing/supportive (MIS) therapy, were compared with brief intervention (BI) treatment in a sample of 677 smokers. Differential efficacy of the 2 step-up treatments was also tested in smokers at low and high risk for relapse (no smoking vs. any smoking during the first postquit week. respectively). All participants received 8 weeks of nicotine patch therapy. BI consisted of 3 brief individual cessation counseling sessions; CBT and MIS participants received BI treatment and 6 group counseling sessions. Neither CBT nor MIS treatment improved long-term abstinence rates relative to BI. Limited support was found for the hypothesis that high-risk smokers would benefit more from MIS than CBT. Other hypotheses were not supported.

Smoking withdrawal dynamics in unaided quitters

Considerable research shows that withdrawal severity is inconsistently related to smoking cessation outcomes. This may result from measurement problems or failure to scrutinize important dimensions of the withdrawal experience. Two recent studies demonstrated that withdrawal elevation and variations in the time course of withdrawal were related to relapse in smokers treated with the nicotine patch (T. M. Piasecki, M. C. Fiore, & T. B. Baker, 1998). This article reports a conceptual replication and extension of those findings in unaided quitters. Evidence for temporal heterogeneity was found across different types of withdrawal symptoms. Patterns or slopes of affect and urge reports over time predicted smoking status at follow-up, as did mean elevation in withdrawal symptoms. These results suggest that affect and urge withdrawal symptoms make independent contributions to relapse and that relapse is related to both symptom severity and trajectory.

Smoking withdrawal dynamics in unaided quitters

Considerable research shows that withdrawal severity is inconsistently related to smoking cessation outcomes. This may result from measurement problems or failure to scrutinize important dimensions of the withdrawal experience. Two recent studies demonstrated that withdrawal elevation and variations in the time course of withdrawal were related to relapse in smokers treated with the nicotine patch (T. M. Piasecki, M. C. Fiore, & T. B. Baker, 1998). This article reports a conceptual replication and extension of those findings in unaided quitters. Evidence for temporal heterogeneity was found across different types of withdrawal symptoms. Patterns or slopes of affect and urge reports over time predicted smoking status at follow-up, as did mean elevation in withdrawal symptoms. These results suggest that affect and urge withdrawal symptoms make independent contributions to relapse and that relapse is related to both symptom severity and trajectory.

Development and validation of the Wisconsin Smoking Withdrawal Scale

The accurate assessment of nicotine withdrawal is important theoretically and clinically. A 28-item scale, the Wisconsin Smoking Withdrawal Scale, was developed that contains 7 reliable subscales tapping the major symptom elements of the nicotine withdrawal syndrome. Coefficients alpha for the subscales range from .75 to .93. This scale is sensitive to smoking withdrawal, is predictive of smoking cessation outcomes, and yields data that conform to a 7-factor structure. The 7 scales predicted intratreatment smoking, chi2(7, N = 163) = 15.19, p = .034. Moreover, the questionnaire is sufficiently brief so that it can be used in both clinical and research contexts.

Development and validation of the Wisconsin Smoking Withdrawal Scale

The accurate assessment of nicotine withdrawal is important theoretically and clinically. A 28-item scale, the Wisconsin Smoking Withdrawal Scale, was developed that contains 7 reliable subscales tapping the major symptom elements of the nicotine withdrawal syndrome. Coefficients alpha for the subscales range from .75 to .93. This scale is sensitive to smoking withdrawal, is predictive of smoking cessation outcomes, and yields data that conform to a 7-factor structure. The 7 scales predicted intratreatment smoking, chi2(7, N = 163) = 15.19, p = .034. Moreover, the questionnaire is sufficiently brief so that it can be used in both clinical and research contexts.

Gender differences in smoking cessation

Gender differences in smoking quit rates are frequently reported and are the subject of much speculation. This study examined the generalizability of gender differences in abstinence across study sites, treatments, and time of relapse, as well as potential mediators and moderators of gender effects. Participants were smokers who participated in 3 randomized clinical trials of the nicotine patch (N = 632). Men had higher cessation rates than women at all follow-ups. The impact of gender on abstinence was unaffected by controlling for study site, treatment, or time of relapse. There was little evidence for mediation or moderation of this relation by any of a host of predictor variables. The magnitude and consistency of the gender differential, coupled with an inability to account for it, highlights a compelling need for additional research specifically aimed at elucidating the relation between gender and abstinence.

Gender differences in smoking cessation

Gender differences in smoking quit rates are frequently reported and are the subject of much speculation. This study examined the generalizability of gender differences in abstinence across study sites, treatments, and time of relapse, as well as potential mediators and moderators of gender effects. Participants were smokers who participated in 3 randomized clinical trials of the nicotine patch (N = 632). Men had higher cessation rates than women at all follow-ups. The impact of gender on abstinence was unaffected by controlling for study site, treatment, or time of relapse. There was little evidence for mediation or moderation of this relation by any of a host of predictor variables. The magnitude and consistency of the gender differential, coupled with an inability to account for it, highlights a compelling need for additional research specifically aimed at elucidating the relation between gender and abstinence.

Gender differences in response to nicotine replacement therapy: objective and subjective indexes of tobacco withdrawal

K. A. Perkins (1996) recently proposed that nicotine reinforcement controls smoking to a greater degree among men than women and that consequently, nicotine replacement therapy (NRT) during smoking cessation should benefit men more than women. The authors tested this hypothesis. Polysomnographic measures of sleep and self-report indexes of tobacco withdrawal were collected pre- and postcessation from an active nicotine patch group and a placebo patch group in a randomized, double-blind clinical trial (N = 34). Objective sleep parameters supported Perkins's hypothesis and indicated that among women, NRT may be less effective at suppressing certain withdrawal responses compared with men and may produce some iatrogenic effects. Valid and reliable self-report measures of withdrawal did not reveal gender differences in response to NRT.