First Report on the OPTN National Variance: Allocation of A2 /A2 B Deceased Donor Kidneys to Blood Group B Increases Minority Transplantation

In 2002, the Organ Procurement and Transplantation Network (OPTN) Minority Affairs Committee (MAC) implemented a national, prospective, "variance of practice" to allow deceased donor, ABO blood group incompatible, A2 antigen, kidney transplantation into blood group B recipients; outcomes of this cohort were compared to ABO compatible recipients. The goal of the variance was to increase the number of transplants to B candidates without negatively impacting survival or compromising system equity. Only B recipients with low anti-A IgG titers (<1:8) were eligible to receive these kidneys. Across eight participating Donation Service Areas (DSA), there were 101 A2 /A2 B to B transplants through 12/31/11, of which the majority of the recipients (61%) were ethnic minorities. At 12, 24, and 36 months, Kaplan-Meier graft survival rates for the B recipients of A2 /A2 B kidneys were 95.0%, 90.6%, and 85.4%, respectively, comparable to outcomes for B recipients of B kidneys, 92.6%, 87.9%, and 82.5%, respectively (p-value = 0.48). Five DSAs increased the proportion of B transplants during 41 months postvariance, with a lesser proportional decrease in blood group A transplants. The data support the proposition that this allocation algorithm may provide a robust mechanism to increase access of blood group B minority candidates to kidney transplantation.

Risk Evaluation of Immediate Surgical Failure During Thigh Hemodialysis Graft Placement by Sonographic Screening

OBJECTIVES

The purpose of this study was to determine whether preoperative sonographic evaluation of vascular diameters and calcification identifies patients at risk for immediate technical failure of thigh hemodialysis grafts.

METHODS

A retrospective analysis of 143 chronic hemodialysis patients who underwent thigh graft placement was performed. All patients underwent preoperative sonography to assess arterial and venous waveforms and vascular diameters. The degree of arterial calcification was assessed retrospectively. Patient characteristics and graft outcomes were examined. Statistical analyses were performed, with P< .05 considered clinically significant.

RESULTS

Sonography identified no or mild arterial calcification in 113 of 143 patients (79%) and moderate to severe calcification in 30 of 143 patients (21%). Primary surgical technical failure occurred in 23% of patients (7 of 30) with moderate to severe calcification, compared to 3.5% (4 of 113) of those with no or mild calcification (hazard ratio, 6.59; 95% confidence interval, 2.06-21.05; P = .002). Cumulative graft survival (time to permanent failure) was shorter in patients with moderate to severe arterial calcification (3-year graft survival, 37% versus 56%; hazard ratio, 2.32; 95% confidence interval, 1.48-6.69; P= .003) but was not significantly associated with venous (P= .82) or arterial (P = .43) diameters.

CONCLUSIONS

Preoperative sonographic assessment of thigh vessel diameters and calcification can identify patients who may be at risk for immediate technical graft failure and decreased cumulative graft survival. The use of sonography as a screening examination may improve preoperative assessment and surgical planning of hemodialysis thigh grafts.

Preoperative arterial microcalcification and clinical outcomes of arteriovenous fistulas for hemodialysis

BACKGROUND

Arteriovenous fistulas (AVFs) often fail to mature, but the mechanism of AVF nonmaturation is poorly understood. Arterial microcalcification is common in patients with chronic kidney disease (CKD) and may limit vascular dilatation, thereby contributing to early postoperative juxta-anastomotic AVF stenosis and impaired AVF maturation. This study evaluated whether preexisting arterial microcalcification adversely affects AVF outcomes.

STUDY DESIGN

Prospective study.

SETTING & PARTICIPANTS

127 patients with CKD undergoing AVF surgery at a large academic medical center.

PREDICTORS

Preexisting arterial microcalcification (≥1% of media area) assessed independently by von Kossa stains of arterial specimens obtained during AVF surgery and by preoperative ultrasound.

OUTCOMES

Juxta-anastomotic AVF stenosis (ascertained by ultrasound obtained 4-6 weeks postoperatively), AVF nonmaturation (inability to cannulate with 2 needles with dialysis blood flow ≥ 300mL/min for ≥6 sessions in 1 month within 6 months of AVF creation), and duration of primary unassisted AVF survival after successful use (time to first intervention).

RESULTS

Arterial microcalcification was present by histologic evaluation in 40% of patients undergoing AVF surgery. The frequency of a postoperative juxta-anastomotic AVF stenosis was similar in patients with or without preexisting arterial microcalcification (32% vs 42%; OR, 0.65; 95% CI, 0.28-1.52; P=0.3). AVF nonmaturation was observed in 29%, 33%, 33%, and 33% of patients with <1%, 1% to 4.9%, 5% to 9.9%, and ≥10% arterial microcalcification, respectively (P=0.9). Sonographic arterial microcalcification was found in 39% of patients and was associated with histologic calcification (P=0.001), but did not predict AVF nonmaturation. Finally, among AVFs that matured, unassisted AVF maturation (time to first intervention) was similar for patients with and without preexisting arterial microcalcification (HR, 0.64; 95% CI, 0.35-1.21; P=0.2).

LIMITATIONS

Single-center study.

CONCLUSIONS

Arterial microcalcification is common in patients with advanced CKD, but does not explain postoperative AVF stenosis, AVF nonmaturation, or AVF failure after successful cannulation.

Pouch adenomas in Familial Adenomatous Polyposis after restorative proctocolectomy

INTRODUCTION

Australian Clinical Practice Guidelines suggest six to twelve-monthly endoscopic pouch surveillance in patients after restorative proctocolectomy for Familial Adenomatous Polyposis (FAP). There are several reports of adenomas and carcinomas forming within the ileum, ileal pouch mucosa or residual rectal mucosa. A retrospective clinical study was performed to audit pouch endoscopic surveillance at a large Sydney tertiary referral Hospital. The aim was to evaluate adenoma development after restorative proctocolectomy for FAP and the adherence rate to published clinical guidelines.

METHODS

Thirty-nine patients who had restorative proctocolectomy for FAP from 1985 to 2011 were identified. Demographic data, details of surgery, original histopathology and details of follow-up pouch endoscopy and pathology findings were obtained.

RESULTS

Of the thirty-nine patients, twenty-seven patients were included in this study. Adenomas were found in twelve of 27 (44%) patients. Mean time to first polyp formation was 88 months and median time was 72 months (range 18-249 months). All polyps were either tubular or tubulovillous in histology. One polyp had high grade dysplasia. The remainder had mild or moderate dysplasia. Polyps were excised either endo-anally or during pouchoscopy. None of the five patients who had a hand-sewn ileal pouch-anal anastomosis (IPAA) developed polyps on follow-up, compared with 12 of the 22 (55%) with a double stapled anastomosis (fishers exact test; p=0.047 (two-tailed)). Of those who developed pouch adenomas, eight (67%) developed further pouch adenomas on follow-up.

CONCLUSIONS

This study supports guidelines recommending lifelong pouch surveillance after restorative proctocolectomy for FAP. Those who develop pouch adenomas may be at greater risk of developing further adenomas. Residual rectal mucosa at the pouch-anal anastomosis should be carefully examined.

A historical comparison of single incision and conventional multiport laparoscopic right hemicolectomy

AIM

Single incision laparoscopic surgery (SILS) is specially suited for surgery of the right colon. This study presents the results of a historical controlled trial comparing single incision and multiport laparoscopic surgery (MLS) for right hemicolectomy.

METHOD

A review of outcome data from 149 patients who underwent laparoscopic right hemicolectomy was performed from the Concord Hospital laparoscopic colorectal database.

RESULTS

Between July 2006 and December 2011, 149 consecutive laparoscopic right hemicolectomies were performed. The first 74 were performed by MLS and from February 2009 all cases were performed by SILS (n = 75).The median ages in the MLS and SILS groups were 74 and 68 years. The median body mass index was 27 kg/m(2) in both groups. Patients were hospitalized for a median of 8 days in the MLS group compared with 5 days in the SILS group. The median length of the extraction wound was 50 mm in the MLS group compared with 43 mm in the SILS group. The indications for surgery were similar in both groups, being 67% and 68%. One patient in each group required conversion to open laparotomy, and no patient in the SILS group required conversion to a conventional multiport technique. Postoperative morbidity was similar in both groups.

CONCLUSION

SILS offers a safe minimally invasive approach to right colon resection. In our series SILS patients had a shorter extraction wound size and shorter length of stay in hospital.

The extent of inflammation is a predictor for pouch-related complications in ileal pouches in patients with ulcerative or indeterminate colitis

AIM

Limited data are available on the relationship between the histological features of the resected specimens in patients with ulcerative colitis (UC) or indeterminate colitis (IC) and the outcome of restorative proctocolectomy. The aim of our study was to determine if the histological features of the resected specimen in patients with UC and IC can predict ileal-pouch-related outcome.

METHOD

A review of all patients who had a restorative proctocolectomy created following completion proctectomy or proctocolectomy for UC and IC was performed.

RESULTS

Between 1992 and 2011, 142 patients (132 with UC and 10 with IC) were reviewed. After a median follow-up of 36 (3-149) months, 51 (35.9%) developed a pouch-related complication. Forty-two (29.7%) developed pouchitis while three (2.1%) developed a pouch-cutaneous fistula. Four (2.8%) had pouch failure, while stricture of the anastomosis was seen in three (2.1%) patients. The presence of extension of the inflammation into the muscularis propria of the resected specimen was associated with an increased risk of pouch-related complications (P = 0.01). The presence of submucosal oedema was also a significant risk factor (P = 0.03).

CONCLUSION

The extension of inflammation into the muscularis propria appears to predict pouch-related complications following restorative proctocolectomy for UC or IC.

Definitive surgical closure of enterocutaneous fistula: outcome and factors predictive of increased postoperative morbidity

AIM

Enterocutaneous fistula (ECF) presents a complex management problem with significant mortality and morbidity. The aim of this study was to assess the outcome of patients undergoing surgical cure for ECF and to predict factors that might relate to increased postoperative morbidity.

METHOD

Medical records of all patients who underwent definitive surgery for cure of an ECF within our colorectal surgery unit between 2000 and 2010 were reviewed.

RESULTS

Forty-one patients (18 male) were identified, in whom 44 definitive procedures were performed. The median age was 54 (17-81) years. The median postoperative length of stay in hospital was 14 (2-213) days. Half (50%) of the ECFs occurred as a postoperative complication followed by spontaneous fistulation in Crohn's disease (36%). The interval to definitive surgery was influenced by the aetiology of the fistula. The median time to surgery after formation of postoperative fistula was 240 days (7.9 months). There was no 30-day postoperative mortality. There were two (4.5%) recurrences at 3 months. Thirty-eight (86%) patients suffered postoperative morbidity as defined by the Clavien-Dindo classification. High-grade morbidity occurred in 32% of patients. On univariate analysis, factors identified as being significantly associated with high-grade morbidity included a fistula output of > 500 ml/day (P = 0.004) in patients with postoperative ECF, malnutrition at presentation (P = 0.04) and a serum albumin value of < 30 g/l (P = 0.02) in patients with spontaneous ECF due to Crohn's disease.

CONCLUSION

The majority of persistent complex ECFs can be cured surgically with low mortality and recurrence in a multidisciplinary setting. Postoperative morbidity, however, remains a significant burden.

Decision-making in rectal surgery

AIM

The decision to create a stoma after anterior resection has significant consequences. Decisions under uncertainty are made with a variety of cognitive tools, or heuristics. Past experience has been shown to be a powerful heuristic in other domains. Our aim was to identify whether the misfortune of recent anastomotic leakage or surgeon propensity to take everyday risks would affect their decision to defunction a range of anastomoses.

METHOD

Questionnaires were sent to members of the Colorectal Surgical Society of Australia and New Zealand. Participants were asked for demographic information, questions regarding risk-taking propensity, when their last anastomotic leakage occurred and whether they would defunction a range of hypothetical rectal anastomoses grouped according to height, American Society of Anesthesiologists grade and use of preoperative radiotherapy. Scores were derived for hypothetical patient likelihood of having a stoma created and individual surgeon propensity for stoma formation. Hazard regression analysis was used to assess demographic predictors of stoma formation.

RESULTS

In total, 110 (75.3%) of 146 surveyed surgeons replied; 72 (65.5%) reported anastomotic leakage within the last 12 months. Surgeons' propensity for risk-taking was comparable (24.6 vs 27.53, 95% confidence interval, Mann-Whitney-U) to previously studied participants in economic models. Surgeon age (< 50 years) and lower propensity for risk-taking were demonstrated to be independent predictors of stoma formation on regression analysis.

CONCLUSION

Although the decision to create a stoma after anterior resection may be made in the belief that its foundation derives from rational thought, it appears that other unrecognized operator factors such as age and risk-taking exert an effect.

Long-term outcome of the anal fistula plug for anal fistula of cryptoglandular origin

AIM

This study aimed to evaluate the long-term outcome of the anal fistula plug in the treatment of anal fistula of cryptoglandular origin.

METHOD

A review of all patients who had at least one anal fistula plug inserted from March 2007 to August 2008 was performed. Only anal fistulae of cryptoglandular origin were included. Success was defined as the closure of the external opening with no further purulent discharge or collection.

RESULTS

Thirty anal fistula plugs were inserted in 26 patients [median age 40 (26-70) years]. Twenty-six of the fistulae were transsphincteric and three were suprasphincteric. One patient had a high intersphincteric fistula, which was the only fistula that did not have a seton inserted. The median duration between seton insertion and the plug procedure was 12 (4-28) weeks. The median length of the fistula tract was 3 (1-7.5) cm. After a median follow-up of 59 (13-97) weeks, 26 (86.7%) fistulae recurred. Of the 26 failures, the median time to failure was 8 (2-54) weeks. Subsequent surgical interventions were performed in 20 of the failures.

CONCLUSION

The role of the fistula plug in the management of anal fistula of cryptoglandular origin remains debatable and warrants further evaluation.

Preoperative venous intimal hyperplasia, postoperative arteriovenous fistula stenosis, and clinical fistula outcomes

BACKGROUND AND OBJECTIVES

Arteriovenous fistulas often fail to mature, and nonmaturation has been attributed to postoperative stenosis caused by aggressive neointimal hyperplasia. Preexisting intimal hyperplasia in the native veins of uremic patients may predispose to postoperative arteriovenous fistula stenosis and arteriovenous fistula nonmaturation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This work explored the relationship between preexisting venous intimal hyperplasia, postoperative arteriovenous fistula stenosis, and clinical arteriovenous fistula outcomes in 145 patients. Venous specimens obtained during arteriovenous fistula creation were quantified for maximal intimal thickness (median thickness=22.3 μm). Postoperative ultrasounds at 4-6 weeks were evaluated for arteriovenous fistula stenosis. Arteriovenous fistula maturation within 6 months of creation was determined clinically.

RESULTS

Postoperative arteriovenous fistula stenosis was equally frequent in patients with preexisting venous intimal hyperplasia (thickness>22.3 μm) and patients without hyperplasia (46% versus 53%; P=0.49). Arteriovenous fistula nonmaturation occurred in 30% of patients with postoperative stenosis versus 7% of those patients without stenosis (hazard ratio, 4.33; 95% confidence interval, 1.55 to 12.06; P=0.001). The annual frequency of interventions to maintain arteriovenous fistula patency for dialysis after maturation was higher in patients with postoperative stenosis than patients without stenosis (0.83 [95% confidence interval, 0.58 to 1.14] versus 0.42 [95% confidence interval, 0.28 to 0.62]; P=0.008).

CONCLUSIONS

Preexisting venous intimal hyperplasia does not predispose to postoperative arteriovenous fistula stenosis. Postoperative arteriovenous fistula stenosis is associated with a higher arteriovenous fistula nonmaturation rate. Arteriovenous fistulas with hemodynamically significant stenosis frequently mature without an intervention. Postoperative arteriovenous fistula stenosis is associated with an increased frequency of interventions to maintain long-term arteriovenous fistula patency after maturation.

Correlation of pre-existing vascular pathology with arteriovenous graft outcomes in hemodialysis patients

BACKGROUND

Arteriovenous grafts (AVGs) are prone to neointimal hyperplasia leading to AVG failure. We hypothesized that pre-existing pathologic abnormalities of the vessels used to create AVGs (including venous intimal hyperplasia, arterial intimal hyperplasia, arterial medial fibrosis, and arterial calcification) are associated with inferior AVG survival.

STUDY DESIGN

Prospective observational study.

SETTING & PARTICIPANTS

Patients with chronic kidney disease undergoing placement of a new AVG at a large medical center who had vascular specimens obtained at the time of surgery (n = 76).

PREDICTOR

Maximal intimal thickness of the arterial and venous intima, arterial medial fibrosis, and arterial medial calcification.

OUTCOME & MEASUREMENTS

Unassisted primary AVG survival (time to first intervention) and frequency of AVG interventions.

RESULTS

55 patients (72%) underwent interventions and 148 graft interventions occurred during 89.9 years of follow-up (1.65 interventions per graft-year). Unassisted primary AVG survival was not associated significantly with arterial intimal thickness (HR, 0.72; 95% CI, 0.40-1.27; P = 0.3), venous intimal thickness (HR, 0.64; 95% CI, 0.37-1.10; P = 0.1), severe arterial medial fibrosis (HR, 0.58; 95% CI, 0.32-1.06; P = 0.6), or severe arterial calcification (HR, 0.68; 95% CI, 0.37-1.31; P = 0.3). The frequency of AVG interventions per year was associated inversely with arterial intimal thickness (relative risk [RR], 1.99; 95% CI, 1.16-3.42; P < 0.001 for thickness <10 vs. >25 μm), venous intimal thickness (RR, 2.11; 95% CI, 1.39-3.20; P < 0.001 for thickness <5 vs. >10 μm), arterial medial fibrosis (RR, 3.17; 95% CI, 1.96-5.13; P < 0.001 for fibrosis <70% vs. ≥70%), and arterial calcification (RR, 2.12; 95% CI, 1.31-3.43; P = 0.001 for <10% vs. ≥10% calcification).

LIMITATIONS

Single-center study. Study may be underpowered to demonstrate differences in unassisted primary AVG survival.

CONCLUSIONS

Pre-existing vascular pathologic abnormalities in patients with chronic kidney disease may not be associated significantly with unassisted primary AVG survival. However, vascular intimal hyperplasia, arterial medial fibrosis, and arterial calcification may be associated with a decreased frequency of AVG interventions.

Observation of associated near-side and away-side long-range correlations in sqrt[s(NN)]=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δø) and pseudorapidity (Δη) are measured in sqrt[s(NN)] = 5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb(-1) of data as a function of transverse momentum (p(T)) and the transverse energy (ΣE(T)(Pb)) summed over 3.1 < η < 4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2 < |Δ η | < 5) "near-side" (Δø ~ 0) correlation that grows rapidly with increasing ΣE(T)(Pb). A long-range "away-side" (Δø ~ π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣE(T)(Pb), is found to match the near-side correlation in magnitude, shape (in Δη and Δø) and ΣE(T)(Pb) dependence. The resultant Δø correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δø modulation for all ΣE(T)(Pb) ranges and particle p(T).

Measurement of Z boson production in Pb-Pb collisions at sqrt[s(NN)]=2.76 TeV with the ATLAS detector

The ATLAS experiment has observed 1995 Z boson candidates in data corresponding to 0.15  nb(-1) of integrated luminosity obtained in the 2011 LHC Pb+Pb run at sqrt[s(NN)]=2.76  TeV. The Z bosons are reconstructed via dielectron and dimuon decay channels, with a background contamination of less than 3%. Results from the two channels are consistent and are combined. Within the statistical and systematic uncertainties, the per-event Z boson yield is proportional to the number of binary collisions estimated by the Glauber model. The elliptic anisotropy of the azimuthal distribution of the Z boson with respect to the event plane is found to be consistent with zero.

Search for dark matter candidates and large extra dimensions in events with a photon and missing transverse momentum in pp collision data at sqrt[s]=7 TeV with the ATLAS detector

Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 4.6 fb(-1) are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates.

Search for magnetic monopoles in sqrt[s]=7 TeV pp collisions with the ATLAS detector

This Letter presents a search for magnetic monopoles with the ATLAS detector at the CERN Large Hadron Collider using an integrated luminosity of 2.0  fb(-1) of pp collisions recorded at a center-of-mass energy of sqrt[s]=7  TeV. No event is found in the signal region, leading to an upper limit on the production cross section at 95% confidence level of 1.6/ϵ  fb for Dirac magnetic monopoles with the minimum unit magnetic charge and with mass between 200 GeV and 1500 GeV, where ϵ is the monopole reconstruction efficiency. The efficiency ϵ is high and uniform in the fiducial region given by pseudorapidity |η|<1.37 and transverse kinetic energy 600-700<E(kin)sinθ<1400  GeV. The minimum value of 700 GeV is for monopoles of mass 200 GeV, whereas the minimum value of 600 GeV is applicable for higher mass monopoles. Therefore, the upper limit on the production cross section at 95% confidence level is 2 fb in this fiducial region. Assuming the kinematic distributions from Drell-Yan pair production of spin-1/2 Dirac magnetic monopoles, the efficiency is in the range 1%-10%, leading to an upper limit on the cross section at 95% confidence level that varies from 145 fb to 16 fb for monopoles with mass between 200 GeV and 1200 GeV. This limit is weaker than the fiducial limit because most of these monopoles lie outside the fiducial region.

Search for direct top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in sqrt[s] = 7 TeV pp collisions using 4.7 fb(-10 of ATLAS data

A search is presented for direct top squark pair production in final states with one isolated electron or muon, jets, and missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV. The measurement is based on 4.7 fb(-1) of data collected with the ATLAS detector at the LHC. Each top squark is assumed to decay to a top quark and the lightest supersymmetric particle (LSP). The data are found to be consistent with standard model expectations. Top squark masses between 230 GeV and 440 GeV are excluded with 95% confidence for massless LSPs, and top squark masses around 400 GeV are excluded for LSP masses up to 125 GeV.

Search for a supersymmetric partner to the top quark in final states with jets and missing transverse momentum at sqrt[s] = 7 TeV with the ATLAS detector

A search for direct pair production of supersymmetric top squarks (t(1)) is presented, assuming the t(1) decays into a top quark and the lightest supersymmetric particle, χ(1)(0), and that both top quarks decay to purely hadronic final states. A total of 16 (4) events are observed compared to a predicted standard model background of 13.5(-3.6)(+3.7)(4.4(-1.3)(+1.7)) events in two signal regions based on ∫Ldt = 4.7 fb(-1) of pp collision data taken at sqrt[s] = 7 TeV with the ATLAS detector at the LHC. An exclusion region in the t(1) versus χ(1)(0) mass plane is evaluated: 370<m(t)(1)}<465 GeV is excluded for m(χ)(1)(0) ~ 0 GeV while m(t)(1) = 445 GeV is excluded for m(χ)(1)(0) ≤ 50 GeV.

Search for supersymmetry in events with three leptons and missing transverse momentum in √[s]=7 TeV pp collisions with the ATLAS detector

A search for the weak production of charginos and neutralinos decaying to a final state with three leptons (electrons or muons) and missing transverse momentum is presented. The analysis uses 2.06 fb(-1) of √[s]=7 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with standard model expectations in two signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric and simplified models. For the simplified models, degenerate lightest chargino and next-to-lightest neutralino masses up to 300 GeV are excluded for mass differences from the lightest neutralino up to 300 GeV.

Stenting large bowel obstruction avoids a stoma: consecutive series of 100 patients

AIM

Large bowel obstruction (LBO) is a surgical emergency that requires urgent operative intervention and often a stoma. The introduction of a self-expanding metallic stent provides an alternative for this group of patients. The aim of this study was to assess prospectively the results in the first 100 consecutive patients with LBO undergoing attempted self-expanding metallic stent insertion at the Royal Prince Alfred Hospital, Sydney, Australia.

METHOD

A prospective consecutive uncontrolled trial of 100 patients having an attempted self-expanding metallic stent insertion for LBO was performed after institutional ethical approval.

RESULTS

The mean age was 63.9 years (range 16-95). Primary colorectal cancer was the most common cause of LBO (61%). A self-expanding metallic stent was inserted with a palliative intent in 89% of patients. An initial technical success rate of 87% was achieved. Overall 30-day mortality was 7% (95% CI, 3.4-13.7%), with only one stent-related death within 30 days of stent insertion. Morbidity occurred in 20% of patients. Surgery was avoided in 69 patients and permanent stoma was avoided in 72 patients. The median follow up was 34.5 months (range 1-64 months).

CONCLUSION

In this uncontrolled study, self-expanding metallic stents had a low morbidity and a low procedure-related mortality. A randomized controlled trial has commenced in our institution, in which length of stay, quality of life, morbidity and mortality of patients with stents are compared with those of patients having open procedures during palliative care for LBO.

Medial fibrosis, vascular calcification, intimal hyperplasia, and arteriovenous fistula maturation

BACKGROUND

Arteriovenous fistulas (AVFs) for hemodialysis frequently fail to mature because of inadequate dilation or early stenosis. The pathogenesis of AVF nonmaturation may be related to pre-existing vascular pathologic states: medial fibrosis or microcalcification may limit arterial dilation, and intimal hyperplasia may cause stenosis.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

Patients with chronic kidney disease (N = 50) undergoing AVF placement.

PREDICTORS

Medial fibrosis, microcalcification, and intimal hyperplasia in arteries and veins obtained during AVF creation.

OUTCOME & MEASUREMENTS

AVF nonmaturation.

RESULTS

AVF nonmaturation occurred in 38% of patients despite attempted salvage procedures. Preoperative arterial diameter was associated with upper-arm AVF maturation (P = 0.007). Medial fibrosis was similar in patients with nonmaturing and mature AVFs (60% ± 14% vs 66% ± 13%; P = 0.2). AVF nonmaturation was not associated with patient age or diabetes, although both variables were associated significantly with severe medial fibrosis. Conversely, AVF nonmaturation was higher in women than men despite similar medial fibrosis in both sexes. Arterial microcalcification (assessed semiquantitatively) tended to be associated with AVF nonmaturation (1.3 ± 0.8 vs 0.9 ± 0.8; P = 0.08). None of the arteries or veins obtained at AVF creation had intimal hyperplasia. However, repeated venous samples obtained in 6 patients during surgical revision of an immature AVF showed venous neointimal hyperplasia.

LIMITATIONS

Single-center study.

CONCLUSION

Medial fibrosis and microcalcification are frequent in arteries used to create AVFs, but do not explain AVF nonmaturation. Unlike previous studies, intimal hyperplasia was not present at baseline, but developed de novo in nonmaturing AVFs.

Ethnic and gender related differences in the risk of end-stage renal disease after living kidney donation

There is limited data pertaining to the risk of End Stage Renal Disease (ESRD) after living kidney donation. The Organ Procurement and Transplantation Network and the Center for Medicare and Medicaid Services databases were used to identify living kidney donors (LKDs) who subsequently developed ESRD and to calculate LKD ESRD rates. We found 126 cases of ESRD among 56 458 LKDs (0.22%) who donated during October 1, 1987-March 31, 2003. The overall LKD ESRD rate was 0.134 per 1000 years at risk, with an average duration of follow-up of 9.8 years. ESRD rates for LKDs overall and for Black, White, male and female donors compared favorably to the ESRD incidence in the general population. The LKD ESRD rate was nearly five times higher for Blacks than for Whites and two times higher for males than females. However, these ethnic and gender-related differences were similar to those previously reported for ESRD in the general population. Our findings do not show an increase in the risk of ESRD for LKDs and support the current practice of living kidney donation. Further research is needed to determine if improved donor screening or follow-up will reduce the risk of postdonation ESRD.

Ethnic and gender related differences in the risk of end-stage renal disease after living kidney donation

There is limited data pertaining to the risk of End Stage Renal Disease (ESRD) after living kidney donation. The Organ Procurement and Transplantation Network and the Center for Medicare and Medicaid Services databases were used to identify living kidney donors (LKDs) who subsequently developed ESRD and to calculate LKD ESRD rates. We found 126 cases of ESRD among 56 458 LKDs (0.22%) who donated during October 1, 1987-March 31, 2003. The overall LKD ESRD rate was 0.134 per 1000 years at risk, with an average duration of follow-up of 9.8 years. ESRD rates for LKDs overall and for Black, White, male and female donors compared favorably to the ESRD incidence in the general population. The LKD ESRD rate was nearly five times higher for Blacks than for Whites and two times higher for males than females. However, these ethnic and gender-related differences were similar to those previously reported for ESRD in the general population. Our findings do not show an increase in the risk of ESRD for LKDs and support the current practice of living kidney donation. Further research is needed to determine if improved donor screening or follow-up will reduce the risk of postdonation ESRD.

Ethnic and gender related differences in the risk of end-stage renal disease after living kidney donation

There is limited data pertaining to the risk of End Stage Renal Disease (ESRD) after living kidney donation. The Organ Procurement and Transplantation Network and the Center for Medicare and Medicaid Services databases were used to identify living kidney donors (LKDs) who subsequently developed ESRD and to calculate LKD ESRD rates. We found 126 cases of ESRD among 56 458 LKDs (0.22%) who donated during October 1, 1987-March 31, 2003. The overall LKD ESRD rate was 0.134 per 1000 years at risk, with an average duration of follow-up of 9.8 years. ESRD rates for LKDs overall and for Black, White, male and female donors compared favorably to the ESRD incidence in the general population. The LKD ESRD rate was nearly five times higher for Blacks than for Whites and two times higher for males than females. However, these ethnic and gender-related differences were similar to those previously reported for ESRD in the general population. Our findings do not show an increase in the risk of ESRD for LKDs and support the current practice of living kidney donation. Further research is needed to determine if improved donor screening or follow-up will reduce the risk of postdonation ESRD.