Large-for-size liver transplantation: a flowmetry study in pigs

Background

Ischemia–reperfusion injury is partly responsible for morbidity in pediatric liver transplantation. Large-for-size (LFS) liver transplantation has not been fully studied in the pediatric population, and the effects of reperfusion injury may be underestimated.

Materials and methods

Thirteen Landrace–Large white pigs weighing 23 kg (range, 17–38 kg) underwent orthotopic liver transplantation. They were divided into two groups according to the size of the donor body: LFS and control (CTRL). After transplantation, the abdominal cavity of the recipient was kept open and portal venous flow (PVF) was measured after 1 h. The ratio of recipient PVF (PVFr) to donor PVF was used to establish correlations with ischemia and reperfusion parameters. Liver biopsies were taken 1 h after transplantation to assess ischemia and reperfusion and to quantify the gene expression of endothelial nitric oxide synthase, interleukin 6, BAX, and BCL.

Results

Recipient weight, total ischemia time, and warm ischemia time were similar between groups. Among hemodynamic and metabolic analyses, pH, central arteriovenous PCO₂ difference, and AST were statistically worse in the LFS group than in the CTRL group. The same was found with endothelial nitric oxide synthase (0.41 ± 0.18 versus 1.56 ± 0.78; P = 0.02) and interleukin 6 (4.66 ± 4.61 versus 16.21 ± 8.25; P = 0.02). In the LFS group, a significant decay in the PVFr was observed in comparison with the CTRL group (0.93 ± 0.08 and 0.52 ± 0.11, respectively; P < 0.001).

Conclusions

The implantation of a graft was responsible for poor hemodynamic status of the recipient 1 h after transplantation. Furthermore, the LFS group demonstrated markers of ischemia and reperfusion that were worse when compared with the CTRL group and exhibited a more significant decrease in PVF from donor to recipient.     

Remote ischemic perconditioning protects the liver from ischemia–reperfusion injury

Background

Ischemia–reperfusion (IR)–induced injury is a frequent sequel of major liver resections. IR injury after prolonged surgical interventions could be the source of increased risk of postoperative morbidity and mortality. Hepatoprotective effects of this new feasible method called remote ischemic perconditioning (RIPER) were investigated in our rat model of IR injury.

Materials and methods

Male Wistar rats underwent ischemia for 60 min on two-thirds of their livers, followed by 1, 6, and 24 h of reperfusion (n = 72, 8 per group). During liver ischemia, but before reperfusion, rats in the treated groups received four cycles of brief infrarenal aortic clamping as perconditioning. Liver microcirculation was monitored by laser Doppler flowmeter parallel with mean arterial pressure measurements. Liver tissue injury and redox homeostasis were investigated. Furthermore, serum tumor necrosis factor alpha (TNF-α) levels were measured.

Results

In the RIPER group, compared with the IR group, serum transaminase levels were significantly lower after each reperfusion period (alanine aminotransferase: 1 h, P < 0.001; 6 h, P < 0.05; 24 h, P < 0.01 and aspartate aminotransferase: 1 h, P < 0.001; 6 h, P < 0.05; 24 h, P < 0.05). Reperfusion microcirculatory parameters significantly improved in the perconditioned group compared with those in the IR group (reperfusion area: P = 0.005; maximal plateau: P = 0.0002). Regarding TNF-α levels, significant differences were detected between the two IR injured groups (RIPER versus IR: 1 h, 34.3 ± 12.8 pg/mL versus 205.7 ± 60.9 pg/mL, P < 0.001; 6 h, 60.6 ± 11.7 pg/mL versus 110.4 ± 21.6 pg/mL, P < 0.05). Results of the histologic assessment and redox state measurements also showed favorable changes.

Conclusions

Our team firstly reported the protective effects of RIPER on liver morphology, redox homeostasis, and microcirculation and proposed the changes of TNF-α expression.     

Effect of Donor–Recipient Age Gradient on Graft Outcomes in Deceased Donor Liver Transplantation

Purpose

Donor age is a well-known factor influencing graft function after deceased donor liver transplantation (DDLT). However, the effect of donors older than recipients on graft outcomes remains unclear. This study investigated the relationship between the donor–recipient age gradient (DRAG) and posttransplant outcomes after DDLT.

Methods

We included 164 adult recipients who underwent DDLT between May 1996 and April 2011. Patients were divided into 2 groups according to the value of DRAG: Negative (DRAG −20 to −1; n = 99) versus positive (DRAG 0–20; n = 65). Medical records were reviewed and laboratory data were retrospectively collected.

Results

The median age of donors and recipients was 43 (range, 10–80) and 46 (range, 19–67) years, respectively. The mean follow-up time was 57.4 months. A positive DRAG had a negative effect on levels of alkaline phosphatase until 2 weeks after transplantation. However, the positive group showed a lower incidence of hepatitis B viral disease recurrence. The 1-, 3-, and 5-year graft survival rates were 80.4%, 76.8%, and 71.4% in the negative group, and 65.8%, 58.4%, and 56.3% in the positive group, respectively. The positive DRAG group showed significantly inferior graft survival compared with the negative DRAG group (P = .036).

Conclusion

This study demonstrated that donors older than recipients had a deleterious effect on graft outcomes. DRAG could be a meaningful determinant of graft survival among DDLT recipients.     

The effects of arterial pressure during normothermic kidney perfusion

Background

Ex vivo normothermic perfusion (EVNP) can reverse some of the detrimental effects of ischemic injury. However, in kidneys with warm and cold ischemic injury the optimal perfusion pressure remains undetermined. The aim of this study was to evaluate the effects of two different arterial pressures during EVNP.

Methods

Porcine kidneys underwent static cold storage for 23 h followed by 1 h of EVNP using leukocyte depleted blood at a mean arterial pressure of either 55 or 75 mm Hg. After this, kidneys were reperfused for 3 h to assess renal function and injury. This was compared with a control group that underwent 24 h cold storage.

Results

During EVNP, kidneys perfused at 75 mm Hg had a higher renal blood flow, increased oxygen consumption (median 59.9 mL/min/g (range 30.1–78.6] versus 31.8 [8.2–53.8] mL/min/g; P = 0.026), and produced more urine (P = 0.002) than kidneys perfused at 55 mm Hg. During ex vivo reperfusion, renal blood flow was significantly higher in the 75 mm Hg and 55 mm Hg groups compared with the control (area under the curve median 75 mm Hg 462 [228–745], 55 mm Hg 454 [254–923] versus control 262 [215–442] mL/min/100g.h; P = 0.040). There was a significant loss of renal function and increase in tubular injury in the 55 mm Hg group kidneys (P = 0.001, 0.007). Levels of endothelin 1 were significantly reduced in the 75 mm Hg group (P = 0.026).

Conclusions

A mean arterial pressure of 75 mm Hg during EVNP resulted in less tubular damage and less endothelial injury during ex vivo reperfusion compared with kidneys perfused at 55 mm Hg.     

The impact of Aldehyde dehydrogenase 1 expression on prognosis for metastatic colon cancer

Background

Cancer stem cells may be associated with tumor progression and prognosis for colon cancer. We hypothesized that expression of Aldehyde dehydrogenase 1 (ALDH1) would increase with tumor progression and be associated with survival.

Methods

Tissue was obtained from resection specimens for isolation of cancer stem cells. In addition, paraffin blocks from resected colon cancers with normal colon, primary tumor, and lymph node and liver metastasis from 2000 to 2010 were identified and stained with ALDH1.

Results

In in vitro models (adherent and tumor spheres) ALHD1+ cells grew more efficiently than ALDH1− cells. ALDH1 expression was highest in peritumoral crypt cells (0.137 μm², 95% confidence interval [CI] 0.125–0.356) and normal crypts (median 0.091 μm², 95% CI 0.064–0.299) followed by lymph node metastasis (median 0.025 μm², 95% CI 0–0.131) and the primary cancers (median 0.014 μm², 95% CI 0.0123–0.154). Samples were divided into high and low ALDH1 expression. Survival was associated with expression in the primary tumor (9 versus 23 mo, P = 0.0016) expression but not peritumoral tissue (21 versus 20.5 mo, P = 0.32), normal colon (19 versus 27 mo, P = 0.289), or lymph node metastasis (23 versus 21 mo, P = 0.69). On univariate analysis, ALDH1 expression and grade were associated with survival but ages, number of lymph node metastasis, race, or grade were not associated. On multivariate analysis, only ALDH1 status continued to be associated with survival, odds ratio 4.4, and P = 0.011.

Conclusions

ALDH1 is indicative of stemness and is a biomarker marker in colon cancer. Expression did not increase with progression from normal colon to primary tumors and metastasis.     

Oxygen consumption predicts outcome in porcine partial liver grafts

Background

High oxygen consumption (OC) in recipients of cadaveric whole liver grafts is associated with a poor prognosis. The aim of this study is to investigate the relationship between intraoperative hepatic OC and graft function and survival in a porcine partial liver graft model.

Material and methods

Experiments followed the Guiding Principles in the Care and Use of Laboratory Animals. Fourteen female pigs, 46–69 kg, received liver allografts of 17%–39% liver volume and were followed for 14 d. We measured donor and recipient body weights, percentage graft weight and expressed it as a percentage of standard liver volume, cold ischemia time, hepatic artery flow (HAF), portal vein flow (PVF), graft volume at sacrifice, serum lactate, prothrombin time, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, albumin, total protein, alkaline phosphatase, total bilirubin, and recipient survival. OC was calculated as follows: OC (mL/100 g/min) = ([Hemoglobin {Hb} × 1.34 × SaO₂ + 0.003 × PaO₂] × HAF + [Hb × 1.34 × SpO₂ + 0.003 × PpO₂] × PVF − [Hb × 1.34 × SvO₂ + 0.003 × PvO₂] × [HAF + PVF])/graft weight (100 g), and animals were divided into two groups: low OC group (OC < 2.0 mL/100 g/min) and high OC group (OC ≥ 2.0 mL/100 g/min).

Results

In survival analysis, four of seven low OC recipients (57% [n = 7]) survived until the end of the study period compared with one of seven high OC recipients (14% [n = 7]). The low OC group had a significantly higher survival rate than that of the high OC group (P = 0.041). Low OC was associated with higher HAF (mL/100 g/min) after reperfusion compared with that of the high OC group, 29.0 ± 13.8 versus 16.0 ± 11.1 mean ± standard deviation; P = 0.073. Serum alkaline phosphatase and total bilirubin in the low OC group were significantly better than those of the high OC group. Serum lactate was comparable in both groups. Graft weight at the time of sacrifice in the low OC group tended to be higher than that in the high OC group, but not significantly (P = 0.097).

Conclusions

High intraoperative OC is associated with lower HAF, decreased graft function, and decreased survival in the porcine partial liver graft model.     

Mild to moderate pulmonary hypertension in liver transplantation

Background

Patients with pulmonary hypertension (PHTN) are at increased risk for worse outcomes post–liver transplant (LT). This study evaluated LT outcomes and complications for a large number of LT patients with mild to moderate PHTN.

Materials and methods

This is a retrospective review of data from 2001 to 2011. All cases of PHTN were diagnosed with catheterization (mean pulmonary artery pressure) and categorized according to standard criteria: low-mild, 25–29 mm Hg; high-mild, 30–34 mm Hg; moderate, 35–44 mm Hg; and severe, ≥45 mm Hg. Our center protocol excludes most patients with known moderate and severe PHTN from LT. Outcomes included early liver function, ventilator time, hospital length of stay, and graft and patient survival.

Results

We reviewed the cardiac and pulmonary records for 1263 patients. There were 102 patients with confirmed PHTN (8%): 63 low-mild, 30 high-mild, and 9 moderate. Patients with PHTN were older (P < 0.001). Patients with PHTN were more likely to have prolonged post-transplant ventilator weaning (40% versus 26% >48 h post-transplant; P < 0.01) and a longer length of hospital stay (12 versus 10 d; P = 0.08). The PHTN had a lower 1-y graft survival (79% versus 87%; P = 0.05). There were no statistical differences in early graft function or in long-term patient survival.

Conclusions

These results suggest that PHTN patients require longer post–liver transplant ventilation and length of hospital stay, but have similar early graft function and long-term survival. The risk of PHTN in these patients increases with increasing age.     

Postconditioning of the small intestine: which is the most effective algorithm in a rat model?

Background

Mesenteric ischemia is a serious clinical condition requiring immediate surgical intervention. The unavoidable ischemic-reperfusion (IR) injury may be ameliorated using the appropriate postconditioning protocol. The aim of the present study was to investigate the optimal postconditioning algorithm in a rat model of intestinal ischemic–reperfusion injury.

Materials and methods

Male Wistar rats were randomized into five groups (n = 10), one sham-operated, one IR, and three postconditioned groups, each with different protocols. The animals were subjected to 60 min of mesenteric ischemia, followed by 60 min of reperfusion. Postconditioning was applied at the onset of reperfusion using three different algorithms. Arterial pressure and mucosal microcirculation were monitored throughout the experiment. Mesenteric pH was determined at the early phase of reperfusion. Blood and tissue samples were taken at the end of reperfusion for histologic evaluation, serum lactate dehydrogenase, serum creatine kinase, serum tumor necrosis factor-α, serum interleukin-6, detailed mucosal antioxidant, and scavenger capacity assays.

Results

The shorter and intermediate length cycles of postconditioning enhanced mucosal microcirculation and redox state and significantly delayed the normalization of mesenteric pH. Furthermore, milder histopathologic lesions and lower concentrations of serum necroenzymes and proinflammatory cytokines were detected compared with the IR group. The protective effect of postconditioning using longer cycles could only be seen in a tendentious manner.

Conclusions

In a rat model of intestinal ischemia–reperfusion, the shorter and intermediate length cycles of postconditioning proved to be more effective than the use of longer cycles.     

Initial assessment on the impact of crystalloids versus colloids during damage control resuscitation

Background

High ratios of fresh frozen plasma:packed red blood cells in damage control resuscitation (DCR) are associated with increased survival. The impact of volume and type of resuscitative fluid used during high ratio transfusion has not been analyzed. We hypothesize a difference in outcomes based on the type and quantity of resuscitative fluid used in patients that received high ratio DCR.

Methods

A matched case control study of patients who received transfusions of ≥ four units of PRBC during damage control surgery over 4 1/2 y, was conducted at a Level I Trauma Center. All patients received a high ratio DCR, >1:2 of fresh frozen plasma:packed red blood cells. Demographics and outcomes of the type and quantity of resuscitative fluids used in combination with high ratio DCR were compared and analyzed. A Kaplan-Meier survival analysis was computed among four groups: colloid (median quantity = 1.0 L), <3 L crystalloid, 3–6 L crystalloid, and >6 L crystalloid.

Results

There were 56 patients included in the analysis (28 in the crystalloid group and 28 in the colloid group). Demographics were statistically similar. Intraoperative median units of PRBC: crystalloid versus colloid groups was 13 (IQR 8-21) versus 16 (IQR 12–19), P = 0.135; median units of FFP: 12 (IQR 7–18) versus 12 (IQR 10–18), P = 0.440. OR for 10-d mortality in the crystalloid group was 8.41 [95% CI 1.65–42.76 (P = 0.01)]. Kaplan-Meier survival analysis demonstrated lowest mortality in the colloid group and higher mortality with increasing amounts of crystalloid (P = 0.029).

Conclusions

During high ratio DCR, resuscitation with higher volumes of crystalloids was associated with an overall decreased survival, whereas low volumes of colloid use were associated with increased survival. In order to improve outcomes without diluting the survival benefit of hemostatic resuscitation, guidelines should focus on effective low volume resuscitation when high ratio DCR is used. A multi-institutional analysis is needed in order to validate these results.     

Graft Regeneration in Pediatric Living Donor Liver Transplantation

Objective

Due to the shortage of cadaver liver grafts in Asia, more than 90% of biliary atresia (BA) patients require living donor liver transplantation (LDLT), but the factors that influence liver graft regeneration in pediatric patients are still unclear. The aim of this study was to evaluate the potential predisposing factors that encourage liver graft regeneration in pediatric liver transplantation (LT).

Methods

Case notes and Doppler ultrasound and computed tomography studies performed before and 6 months after transplantation of 103 BA patients who underwent LDLT were reviewed. The predisposing factors that triggered liver regeneration were compiled from statistical analyses and included the following: age, gender, body weight and height, spleen size, graft weight–to–recipient weight ratio (GRWR), post-transplantation total portal flow, and vascular complications.

Results

Seventy-two pediatric recipients were enrolled in this study. The liver graft regeneration rate was 29.633 ± 36.61% (range, −29.53–126.27%). The size of the spleen (P = .001), post-transplantation portal flow (P = .004), and age (P = .04) were correlated lineally with the regeneration rate. The GRWR was negatively correlated with the regeneration rate (P = .001) and was the only independent factor that affected the regeneration rate. When the GRWR was >3.4, patients tended to have poor and negative graft regeneration (P = .01).

Conclusion

Large-for-size grafts have negative effect on regeneration rates because liver grafts that are too large can compromise total portal flow and increase vascular complications, especially when the GRWR is >3.4. Thus, optimal graft size is more essential than other factors in a pediatric LDLT patient.     

L-alpha-glycerylphosphorylcholine reduces the microcirculatory dysfunction and nicotinamide adenine dinucleotide phosphate-oxidase type 4 induction after partial hepatic ischemia in rats

Background

We set out to investigate the microcirculatory consequences of hepatic ischemia–reperfusion (IR) injury and the effects of L-alpha-glycerylphosphorylcholine (GPC), a deacylated phospholipid derivative, on postischemic hepatocellular damage, with special emphasis on the expression of nicotinamide adenine dinucleotide phosphate oxidase type 4 (NOX4), which is predominantly expressed in hepatic microvessels.

Materials and methods

Anesthetized male Sprague–Dawley rats were subjected to 60-min ischemia of the left liver lobes and 180-min reperfusion, with or without GPC treatment (50 mg/kg intravenously 5 min before reperfusion, n = 6 each). A third group (n = 6) served as saline-treated control. Noninvasive online examination of the hepatic microcirculation was performed hourly by means of modified spectrometry. Plasma tumor necrosis factor (TNF-α), high-mobility group box 1 protein (HMGB1), plasma aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels, tissue xanthine oxidoreductase (XOR) and myeloperoxidase (MPO) activities, and expressions of NOX2 and NOX4 proteins were determined.

Results

Liver IR resulted in significant increases in NOX2 and NOX4 expressions and XOR and MPO activities, and approximately 2-fold increases in the levels of the inflammatory cytokines TNF-α and HMGB1. The microvascular blood flow and tissue oxygen saturation decreased by ∼20% from control values. GPC administration ameliorated the postischemic microcirculatory deterioration and reduced the liver necroenzyme levels significantly; the NOX4 expression, MPO activity, and HMGB1 level were also decreased, whereas the NOX2 expression, TNF-α level, and XOR activity were not influenced by GPC pretreatment.

Conclusions

NOX4 activation is a decisive component in the IR-induced microcirculatory dysfunction. Exogenous GPC ameliorates the inflammatory activation, and preserves the postischemic microvascular perfusion and liver functions, these effects being associated with a reduced hepatic expression of NOX4.     

Fenofibrate does not affect burn-induced hepatic endoplasmic reticulum stress

Background

Burn injury causes major metabolic derangements such as hypermetabolism, hyperlipidemia, and insulin resistance and is associated with liver damage, hepatomegaly, and hepatic endoplasmic reticulum (ER) stress. Although the physiological consequences of such derangements have been delineated, the underlying molecular mechanisms remain unknown. Previously, it was shown that fenofibrate improves patient outcome by attenuating postburn stress responses.

Methods

Fenofibrate, a peroxisome proliferator–activated receptor alpha agonist, regulates liver lipid metabolism and has been used to treat hypertriglyceridemia and hypercholesterolemia for many years. The aim of the present study is to determine the effects of fenofibrate on burn-induced hepatic morphologic and metabolic changes. We randomized rats to sham, burn injury, and burn injury plus fenofibrate. Animals were sacrificed and livers were assessed at 24 or 48 h post burn.

Results

Burn injury decreased albumin and increased alanine transaminase (P = 0.1 versus sham), indicating liver injury. Fenofibrate administration did not restore albumin or decrease alanine transaminase. In addition, ER stress was significantly increased after burn injury both with and without fenofibrate (P < 0.05 versus sham). Burn injury increased fatty acid metabolism gene expression (P < 0.05 versus sham), downstream of peroxisome proliferator–activated receptor alpha. Fenofibrate treatment increased fatty acid metabolism further, which reduced postburn hepatic steatosis (burn versus sham P < 0.05, burn + fenofibrate versus sham not significant).

Conclusions

Fenofibrate did not alleviate thermal injury–induced hepatic ER stress and dysfunction, but it reduced hepatic steatosis by modulating hepatic genes related to fat metabolism.     

Preconditioning renoprotective effect of isoflurane in a rat model of virtual renal transplant

Background

The development of warm–cold ischemia–reperfusion (IR) injury of the kidney grafts is inevitable during renal transplantation. However, there is currently no definite renoprotective strategy available in the protection of the graft tissue. In the present study, we compared the renal protection of preconditioning isoflurane with N-acetylcysteine (NAC) in a novel rat model of warm–cold renal IR injury.

Materials and methods

Adult Sprague–Dawley rats were randomly assigned to receive inhaled isoflurane (1.5% for 2 h), NAC (1 g/kg, intra-arterial injection) or placebo before the induction of brief warm ischemia (10 min) followed by cold ischemia (45 min) periods. Plasma levels of creatinine and tissue inflammatory reaction in the kidney were analyzed 72 h after reperfusion.

Results

Elevated plasma level of creatinine and urea indicated the development of acute renal injury secondary to IR injury. The creatinine levels were reduced in animals pretreated with inhaled isoflurane and NAC, and the level was more significantly decreased in the isoflurane-treated group. Preconditioning with volatile isoflurane also significantly suppressed the tissue myeloperoxidase activity and expression of the inducible nitric oxide synthase. Immunostaining confirmed that myeloperoxidase expression was most significantly attenuated in the glomerulus and peritubular capillaries of rats pre-exposed to isoflurane.

Conclusions

We present the first study demonstrating that the administration of volatile isoflurane before induction of experimental warm–cold renal IR injury provides preconditioning renoprotective effect, which is superior to the treatment with NAC. The beneficial renoprotective effect of isoflurane is most likely mediated by attenuation of proinflammatory reaction in the injured kidney.     

Morbidity related to concomitant adhesions in abdominal surgery

Background

We sought to assess the independent effect of concomitant adhesions (CAs) on patient outcome in abdominal surgery.

Materials and methods

Using the American College of Surgeons National Surgical Quality Improvement Program data, we created a uniform data set of all gastrectomies, enterectomies, hepatectomies, and pancreatectomies performed between 2007 and 2012 at our tertiary academic center. American College of Surgeons National Surgical Quality Improvement Program data were supplemented with additional variables (e.g., procedure complexity–relative value unit). The presence of CAs was detected using the Current Procedural Terminology codes for adhesiolysis (44005, 44180, 50715, 58660, and 58740). Cases where adhesiolysis was the primary procedure (e.g., bowel obstruction) were excluded. Multivariable logistic regression analyses were performed to assess the independent effect of CAs on 30-d morbidity and mortality, while controlling for age, comorbidities and the type/complexity/approach/emergency nature of surgery.

Results

Adhesiolysis was performed in 875 of 5940 operations (14.7%). Operations with CAs were longer (median duration 3.2 versus 2.7 h, P < 0.001), more complex (median relative value unit 37.5 versus 33.4, P < 0.001), performed in sicker patients (American Society for Anesthesiologists class ≥3 in 49.9% versus 41.2%, P < 0.001), and harbored higher risk for inadvertent enterotomies (3.0% versus 0.9%, P < 0.001). In multivariable analyses, CAs independently predicted higher morbidity (adjusted odds ratio [OR], 1.35; 95% confidence interval, 1.13–1.61, P = 0.001). Specifically, CAs independently correlated with superficial and deep or organ-space surgical site infections (OR = 1.42 (1.02–1.86), P = 0.036; OR = 1.47 (1.09–1.99), P = 0.013, respectively), and prolonged postoperative hospital stay (≥7 d, OR = 1.34 [1.11–1.61], P = 0.002). No difference in 30-d mortality was detected.

Conclusions

CAs significantly increase morbidity in abdominal surgery. Risk adjusting for the presence of adhesions is crucial in any efforts aimed at quality assessment and/or benchmarking of abdominal surgery.     

Recipient-Donor Age Matching in Liver Transplantation: A Single-Center Experience

Objective

The aim of this study was to investigate whether donor age was a predictor of outcomes in liver transplantation, representing an independent risk factor as well as its impact related to recipient age-matching.

Methods

We analyzed prospectively collected data from 221 adult liver transplantations performed from January 2006 to September 2009.

Results

Compared with recipients who received grafts from donors <60 years old, transplantation from older donors was associated with significantly higher rates of graft rejection (9.5% vs 3.5%; P = .05) and worse graft survival (P = .021). When comparing recipient and graft survivals according to age matching, we observed significantly worse values for age-mismatched (P values .029 and .037, respectively) versus age-matched patients. After adjusting for covariates in a multivariate model, age mismatch was an independent risk factor for patient death (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.1–4.17; P = .027) and graft loss (HR 3.86, 95% CI 1.02–15.47; P = .046).

Conclusions

The results of this study suggest to that optimized donor allocation takes into account both donor and recipient ages maximize survival of liver-transplanted patients.     

Racial disparity in early graft failure after infrainguinal bypass

Background

Racial disparities have been shown to be associated with increasing health-care costs. We sought to identify racial disparities in 30-d graft failure rates after infrainguinal bypass in an effort to define targets for improved health care among minorities.

Methods

The 2005–2011 National Surgical Quality Improvement Program database was queried for patients with peripheral arterial disease who underwent infrainguinal bypass as their primary procedure. A bivariate analysis was done to assess pre and intraoperative risk factors across race (whites, blacks, and Hispanics). Multivariate logistic regression was performed to assess the independent association of race with 30-d graft failure.

Results

Of a total of 16,276 patients, 12,536 (77.0%) were whites, 2940 (18.1%) blacks, and 800 (4.9%) Hispanics. Black patients were more likely to be younger, female, current smokers, and on dialysis (P < 0.001, all). In addition, whites were less likely to present with critical limb ischemia compared with blacks and Hispanics (44.2 versus 55.4 versus 52.8%, respectively; P < 0.001). Similarly, fewer whites underwent femoral-tibial (31.4 vs. 34.7 vs. 38.6% respectively) or popliteal-tibial level bypasses (8.9 versus 13.4 versus 16.1%, respectively) than blacks and Hispanics (P < 0.001, all). There was no difference in the use of autogenous conduit across the groups (P = 0.266). Proportionally more blacks than whites developed early graft failure (6.7 versus 4.5%; P < 0.001) but there was no difference comparing Hispanics to whites (6.0 versus 4.5%; P = 0.057). On multivariable analysis, black race remained independently associated with early graft failure (adjusted odds ratio = 1.26, 95% confidence interval 1.05–1.51; P = 0.011).

Conclusions

More blacks and Hispanics present with critical limb ischemia, requiring distal revascularization. Even when controlling for anatomic differences and degree of peripheral arterial disease, black race remained independently associated with early graft failure after infrainguinal bypass. These results identify a target for improved outcomes.     

Effects of statins on ischemia–reperfusion complications in breast free flaps

Background

Administration of statins or other cardiovascular medications (CVMs) could potentially protect against the development of ischemia–reperfusion (I/R) injury in free flap reconstruction. The aim of this study was to examine whether the use of statins and other CVMs decreased the rate of I/R injury in autologous free flap breast reconstruction.

Methods

Retrospective chart review was performed on women who had undergone mastectomy and autologous free flap breast reconstruction between 2004 and 2010. Patient characteristics, use of statin and/or CVMs, and I/R–related complications were ascertained. Multivariable logistic regression was used to identify associations between independent risk factors and specific complications.

Results

There were 702 free flap breast reconstructions included in this study; 45 performed in patients on statins, 70 in patients on CVMs, and 38 in patients on both. Overall complication rate in patients on statins and patients on CVMs was significantly higher than those not on any medication (46.7% versus 31.5%, P = 0.037 and 45.7% versus 31.5%, P = 0.017, respectively). When I/R complications were pooled, there were no significant differences between patients not on any medications and those on statins (P = 0.26), CVMs (P = 0.18), and both (P = 0.83.)

Conclusions

Although there may be theoretical pharmacologic benefits of statins and/or CVMs to reduce the incidence of IR injury in autologous free flap breast reconstruction, the results of this study showed no clear advantages when these drugs were used.     

Factors Associated With Consciousness Recovery Time After Liver Transplantation in Recipients With Hepatic Encephalopathy

Background

Hepatic encephalopathy (HE) occurs as a result of liver failure and is often considered to be a clinical indication for liver transplantation (LT). An assessment of post-transplantation consciousness level in recipients with HE is crucial, because recovery of consciousness implies reestablishment of transplant liver function and lack of perioperative brain damage. The purpose of this study is to evaluate factors associated with consciousness recovery time after LT in recipients with HE.

Methods

Out of 633 adult recipients who underwent LT, recipients who exhibited HE at the time of LT were analyzed retrospectively. The time between graft reperfusion and postoperative consciousness recovery was determined, and recipients were divided into 2 groups: group E with recovery of consciousness early (≤48 hours), and group L with recovery of consciousness late (>48 hours). Analyzed variables included recipient sex, age, graft type, Model for End-Stage Liver Disease score, HE history/duration/type/grade, and preoperative laboratory values, including blood ammonia concentration.

Results

HE was present at the time of LT in 69 (10.9%) of 633 recipients. Among the 69 recipients, 11 recipients who died or underwent reoperation before consciousness recovery were excluded, and 58 recipients (group E: n = 32; group L: n = 26) were enrolled into analysis. Multivariate analysis showed that HE duration >5 days (odds ratio [OR], 15.58; 95% confidence interval [CI], 1.35–179.56; P = .028) and HE type C (OR, 30.90; 95% CI, 1.67–573.48; P = .021) were the independent factors associated with late recovery from HE after LT.

Conclusions

We suggest that recipients with long-duration or type C HE should be carefully managed during the post-transplantation period to prevent deterioration of HE.