PURLS: It's time to reconsider early-morning testosterone tests.

Guidelines recommend collecting an early-morning sample to compensate for the natural diurnal variation in testosterone levels. But for men 45 and older, this is unnecessary. Because the natural diurnal variation in testosterone levels tends to diminish with age, it is acceptable to test men ages 45 and older before 2 pm.

Education of the modern surgical resident: novel approaches to learning in the era of the 80-hour workweek.

INTRODUCTION: Implementation of the 80-hour work week has resulted in limitations on the hours available for resident education, creating a need for innovative approaches to teach surgical residents successfully. Herein we report the methods and results of an innovative didactic learning program at a large academic surgical residency program. METHODS: Between 2004 and 2005, based on known principles of adult education and innovative learning techniques, a didactic learning program was instituted in a major academic surgery program. The course work consisted of a structured reading program using Schwartz's Textbook of Surgery, with weekly testing and problem-based learning (PBL) groups led by surgical faculty. The residents' progress was assessed by American Board of Surgery In-Training Examination (ABSITE) training scores before and after program implementation. A resident survey was also conducted to assess residents' attitudes toward the new program. Results were reported as a mean, and categoric variables were compared using a paired Student's t-test. RESULTS: During the academic year of the structured reading program, the mean ABSITE score improved by 10% (P=0.02) from the previous year. The postgraduate year 4 class had the largest change, with a score increase of 17% over the previous year's performance (P=0.02). Survey results demonstrated that 64% of the responders agreed that the small-group PBL was preferable for achieving educational goals. Furthermore, 89% of residents responded that the PBL groups improved interaction between residents and faculty members. CONCLUSIONS: An innovative formal learning program based on a major surgical textbook with weekly testing and small group sessions can significantly improve surgical training in the modern era of work-hour restrictions. Furthermore, surgical trainees find this format to be innovative and useful for improving didactic teaching.

Carotid artery aneurysm: evolution of management over two decades.

INTRODUCTION: Extracranial carotid artery aneurysm (CCA), although uncommon, represents a challenge to treatment strategy. The purpose of this study was to analyze the treatment evolution and clinical outcome of all patients with CCA over a two decade period. METHODS: Clinical data of all patients diagnosed with CCA who underwent interventions from 1984 to 2004 were reviewed. Patients were divided into two groups. Group I (1985-1994) and group II (1995-2004) were compared with regards to clinical presentation, treatment modality, and clinical outcome. RESULTS: A total of 42 cases of CCA were found during the study period (group I, n=22; group II, n=20). Pulsatile neck mass was the most common presenting symptom (n=39, 93%), followed by neurological symptoms (n=6, 14%). Twenty two (52%) were atherosclerotic aneurysms, fifteen (36%) false aneurysms, and five (12%) posttraumatic aneurysms. Both groups shared similar comorbidities and demographic profiles. All patients in group I underwent operative interventions, which included 12 resection with interposition bypass grafting (55%), six resection with patch angioplasty (27%), and four carotid ligation (18%). In group II, five patients underwent resection with interposition placement (25%) and one carotid ligation (5%). The remaining 14 patients underwent endovascular interventions (70%) which included seven stent-graft exclusions, six carotid stenting with coil exclusions, and one endovascular occlusion. Hospital length of stay was significantly shorter in group II than group I (3.5 vs. 9.4 days, p<0.01). The incidence of cranial nerve injury in group I and II were 14% vs. 5% (p<0.04), respectively. The 30-day mortality/major stroke rates in group I and II were 14% vs. 5% (p< 0.04), respectively. During the follow-up period (0.8 months-20 years; mean, 4.6 years), 16 patients died, largely due to cardiac etiologies (n=11, 69%). CONCLUSIONS: Treatment modality of CCA has largely evolved from operative to endovascular intervention at our institution. Treatment benefits of endovascular modality include shorter convalescent and less procedural-related complications. This evolution reflects the improvement of endovascular devices and increased utility of endovascular applications.

Anastomotic strategies to improve hemodialysis access patency--a review.

The number of patients with end-stage renal disease (ESRD) who require maintenance hemodialysis has risen sharply in the past 2 decades. It is estimated that more than 60% of all patients with ESRD who require chronic hemodialysis are accessed through an arteriovenous fistula (AVF) or graft (AVG), and the incidence is increasing at a rate of 2% to 4% per year. The long-term patency rate of an upper extremity AVF or AVG for hemodialysis access remains suboptimal owing in part to progressive stenosis at the venous anastomosis. This article reviews the causative factors of dialysis access-related anastomotic stenosis, or intimal hyperplasia. This article also reviews the clinical experience of various anastomotic strategies to ameliorate the hemodynamic environment in an effort to improve the clinical outcome of hemodialysis access. These strategies include the use of (1) vein cuff at the expanded polytetrafluoroethylene (ePTFE)-venous anastomosis of AVG, (2) cuffed ePTFE dialysis AVG, and (3) anastomotic devices that create an interrupted anastomosis with staples or clips.

Hormone replacement therapy and peripheral vascular disease in women.

Women have been shown to have a lower incidence of vascular disease when compared to men. However, the incidence of vascular disease increases as women progress through menopause and reaches an incidence similar to that of men later in life. Women with peripheral vascular disease often have a delay in diagnosis, a higher incidence of asymptomatic disease, and poorer outcome after interventions. The differences in outcome have been attributed to a number of factors such as anatomic and hormonal differences. It is thought that estrogen deficiency is at least partially responsible for the increased risk of developing vascular disease after menopause, and thus hormone replacement therapy has been considered as a method to prevent progression of vascular disease. Conclusions drawn from a number of recent studies have resulted in a divergent view of hormone replacement therapy (HRT). This article explores the risk of peripheral vascular disease in women and the current state of research on hormone replacement therapy. The aims of this review are to present current perspectives on gender differences in the pathogenesis and outcomes of peripheral arterial disease (PAD). The effect of estrogen on atherogenesis, the role it plays in modulating the vascular endothelium, and the current evidence of the effects of HRT on vascular pathology is discussed. The most recent HRT clinical trials and present evidence for the benefits and risks of postmenopausal hormone replacement therapy are summarized. The effect of these issues on treatment practices is explained and suggestions are made for future directions of HRT and PAD research.

The impact of anesthetic modality on the outcome of carotid endarterectomy.

BACKGROUND: Carotid endarterectomy (CEA) reduces the risk of stroke in patients with high-grade carotid artery stenosis. This study evaluates the clinical outcome of CEA performed under local anesthesia (LA) versus general anesthesia (GA). METHODS: Clinical variables and treatment outcomes were analyzed in 548 CEAs performed under either LA or GA during a 30-month period. Factors associated with morbidity were also analyzed. RESULTS: A total of 263 CEAs under LA and 285 CEA under GA were analyzed. The LA group was associated with a lower incidence of shunt placement, operative time, and perioperative hemodynamic instability compared to the GA group. No differences in neurologic complications or mortality were found between the 2 groups. Hyperlipidemia was a risk factor for postoperative morbidity in both the LA and GA groups, while age greater than 75 years was associated with increased overall morbidity in the GA group but not the LA group. CONCLUSIONS: This study demonstrates that increased age is associated with increased morbidity in CEA under GA, while hyperlipidemia is associated with increased morbidity in CEA regardless of the anesthetic choice.

Use of a predictive equation for diagnosis of acute gangrenous cholecystitis.

BACKGROUND: Factors previously identified by multivariate logistic regression that were predictive for gangrenous cholecystitis (GC) were used to develop a predictive equation. Our objective was to evaluate the sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of this equation for detecting GC in patients with acute cholecystitis (AC). METHODS: Medical records of patients who presented to a tertiary care hospital with AC were reviewed. Twenty-one patient and clinical variables were recorded. We prospectively tested the results of the following equation against pathologic diagnosis: P=e((0.7116+0.9944.DM+1.7157.WBC-1.0319.ALT.2.0518.ALP+2.7078.PCF))/(1+e([-0.7116+0.9944.DM+1.7157.WBC-1.0319.ALT-2.0518.ALP+2.7078.PCF])), where P = predicted value; DM = diabetes mellitus; WBC = white blood cell count; ALT = alanine aminotransferase; AST = aspartate aminotransferase; and PCF = pericholecystic fluid. RESULTS: Ninety-eight patients presented with AC and 18% had GC (18 of 98). Using a cutoff of P = 0.724, our equation had a specificity of 93%, sensitivity of 83%, PPV of 71%, and NPV of 96%, P <0.001 for the detection of GC. CONCLUSIONS: Our study demonstrates the equation may be useful in detecting the subset of AC patients who have GC.

Cell-specific cytotoxicity of human pancreatic adenocarcinoma cells using rat insulin promoter thymidine kinase-directed gene therapy.

The formation of a normal pancreas and the activation of insulin production are, in part, dependent on the expression and activation of the pancreatic duodenal homeobox gene 1 (PDX-1). The expression of PDX-1 also has been detected in various human pancreatic ductal adenocarcinoma (PDA) cell lines. This has made it possible to generate a cancer cell-specific gene expression system to treat human pancreatic cancer. In this study, we have developed a cell-specific cytotoxic model of PDA cells using the expression of herpes simplex virus thymidine kinase (TK) under the control of the rat insulin promoter (RIP-TK). We have shown that the cell-specific cytotoxicity in human PDA cells depends on the presence of PDX-1. Our results also demonstrate that in vivo PDA-specific cytotoxicity can be achieved with RIP-TK using an intraperitoneal liposomal gene delivery method followed by a short period of ganciclovir treatment in severe combined immunodeficient (SCID) mice. Furthermore, PDX-1 protein was found in all six freshly isolated human pancreas cancer specimens and two liver metastasis samples that were group-tested, suggesting the feasibility of using RIP-TK gene therapy in humans. This study may provide an alternative strategy for the future treatment of pancreatic cancer.

Procurement of the human pancreas for pancreatic islet transplantation.

BACKGROUND: The full potential of pancreatic islet transplantation (PIT) has not been realized because of the difficulties associated with islet isolation, particularly when associated with a remote islet isolation center. Herein, we describe the principles of pancreatic procurement for PIT, which have allowed us to achieve a successful pancreatic islet isolation rate 67% of the time when using a remote islet isolation center. METHODS: Between January 16, 2002 and June 30, 2003, 39 pancreata were procured and processed for PIT at a distant islet isolation center. All pancreata were procured by a single surgeon, and special attention was given to careful dissection of the pancreas, maintenance of arterial inflow and the pressure differential between arterial and venous systems during perfusion, rapid organ cooling, and rapid removal of the pancreas from the body. RESULTS: Twenty-six of 39 (67%) procured pancreata yielded more tha 5,000 islet equivalents (IEQ)/kg recipient weight and were transplanted. Median IEQs per isolation was 413,867, whereas median purity and viability were 65% and 100%, respectively. The median time for pancreatic excision was 34 minutes, whereas cold ischemia time was 6 hours and 40 minutes. DISCUSSION: The principles we have adopted for pancreatic procurement for PIT have resulted in a 67% islet isolation success rate despite the maintenance of more than 5,000 IEQ/kg and the use of a remote islet isolation center.

Acute arterial thrombosis associated with cocaine abuse.

PURPOSE: Cocaine-induced arterial thrombosis is uncommon, and most reported cases involved small-diameter vessels such as the cerebral and coronary arteries. This study was undertaken to review our experience with peripheral arterial thrombosis presumed caused by cocaine abuse. METHODS: Hospital records were reviewed for all patients admitted over 10 years with acute arterial occlusion involving the peripheral arterial system. Patients with confirmation of cocaine use or of its derivative, crack cocaine, within 24 hours of hospital admission formed the basis of this study. Symptoms at presentation, management, and outcome in these patients were reviewed. RESULTS: Three hundred eighty-two patients with acute peripheral arterial occlusion were identified during the study period. The presumptive diagnosis of cocaine-induced arterial occlusion was made in 5 patients (4 men, mean age 38 years). Cocaine use was achieved via intranasal inhalation in 2 patients (40%), whereas the 3 remaining patients smoked crack cocaine (60%). The mean time between cocaine use and onset of arterial thrombosis was 9.2 hours (range, 2-20 hours). Symptoms at presentation included acute limb ischemia without pedal Doppler signals (3 patients, 60%) and abdominal pain without femoral pulses (2 patients, 40%). Arterial occlusion was confirmed on angiograms in all patients, which revealed aortic thrombosis in 1 patient (20%), iliac thrombosis in 2 patients (40%), superficial femoral artery thrombosis in 1 patient (20%), and popliteal artery occlusion in 1 patient (20%). Surgical thrombectomy was successfully performed in 4 patients (80%), and 1 patient (20%) underwent successful thrombolytic therapy for femoropopliteal artery occlusion. There was no perioperative mortality. All 5 patients who were discharged were available for follow-up (mean, 36 months; range, 6-75 months). There was 1 late death from myocardial infarction. In 1 patient recurrent lower extremity arterial thrombosis developed after 28 months, which was successfully treated with thrombolytic therapy. CONCLUSIONS: Our study underscores cocaine abuse as a potential cause of acute arterial thrombosis. Cocaine-induced arterial thrombosis should be suspected in patients with recent history of cocaine abuse with acute limb ischemia without an identifiable source or overt cardiovascular risk factors. Prompt angiography with operative or endovascular intervention should be performed to avert arterial ischemic sequelae.