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Biomedical subjects

G W Barone

Publications and source records attributed to G W Barone.

At least 37 records · Page 2Linked to original sources
PubMed1998

A practical approach to laparoscopic surgery for malfunctioning peritoneal dialysis catheters.

Peritoneal dialysis is widely accepted for the chronic management of end-stage renal disease but is associated with as high as a 70% complication rate including a significant problem with peritoneal dialysis catheter flow obstruction. The application of laparoscopic surgical techniques has revolutionized the surgical approach to peritoneal dialysis catheter-related dysfunction. However, the specific laparoscopic surgical technique varied among the reported literature. This lack of a standard laparoscopic surgical approach to obstructed peritoneal dialysis catheters prompted us to review and compare our specific technique and experience in 17 patients with 10 recent reported series. We specifically examined for insufflation techniques, access port placements and closures, timing postoperatively for reinstituting peritoneal dialysis, wound complications, and overall long-term success rates for peritoneal dialysis catheter salvage.

Adult↗
PubMed1998

The enteric drained pancreas transplant: another potential source of gastrointestinal bleeding.

With most combined kidney and pancreas transplants the transplant pancreatic exocrine secretions are managed with urinary bladder drainage. Because of the associated metabolic and infectious complications, many pancreatic transplants require later conversion to enteric drainage, and the trend in this country is now toward primary enteric drainage. Unlike with urinary bladder drainage when direct cystoscopy can be performed, a disadvantage with enteric drainage is that problems such as bleeding from a transplanted pancreas and attached duodenal segment are not easily evaluated. A case of a cytomegalovirus-related bleeding ulcer in an enteric drained pancreas is presented, along with a review of the possible diagnostic evaluation.

Adult↗
PubMed1998

The anterior extrapleural approach to the thoracolumbar junction revisited.

General surgeons often provide the exposure for the anterior repair of vertebral body lesions. The standard anterior approach to the thoracolumbar junction (T11-L1) is a transpleural 9th or 10th rib thoracoabdominal incision. From October 1995 through March 1997, 22 patients underwent anterior repair of thoracolumbar junction vertebral lesions through an alternative 11th rib resection while maintaining an extrapleural approach. Exposure was excellent, as judged by the neurosurgical team completing the repairs. Chest tubes were not used routinely, and all patients healed without complications. A major limitation of the 11th rib extrapleural approach to the thoracolumbar junction has been poor exposure. This problem is eliminated with the use of an abdominal self-retaining retractor system. With many potential advantages to this 11th rib exposure (less pain, fewer pulmonary problems, and better wound healing), we consider the 11th rib incision to be the approach of choice to the thoracolumbar junction and recommend renewed interest in this incision.

Follow-Up Studies↗
PubMed1998

The Little Rock weave.

A debate has raged in the surgical literature about the use of a running suture verses interrupted sutures for abdominal wound closures. For most abdominal wounds either method can probably be used safely. A modified interrupted technique is described which may be useful for some difficult wounds. One of the main advantages of this technique is that the wound tension is equally distributed along the entire wound and not only on the last placed suture. The sutures are easily tied without having "to fight the wound".

Abdominal Muscles↗
PubMed1998

An improved retractor for the anterior approach in the surgical management of vertebral fractures.

Interest appears to be increasing in the anterior approach for the surgical management of thoracic and lumbar vertebral fractures. However, adequate exposure requires a self-retaining retractor system. Current stainless steel systems, by interfering with fluoroscopic visualization of bony fractures and landmarks, require frequent repositioning. We found that a newly available aluminum alloy retractor system provides excellent operative exposure without significant fluoroscopic obstruction. This system eliminates the frustration of frequent retractor repositioning and saves us an average of 20 to 30 minutes of operating room time per vertebral repair.

Aluminum↗
PubMed1997

Prevalence and associations of abdominal aortic aneurysm detected through screening. Aneurysm Detection and Management (ADAM) Veterans Affairs Cooperative Study Group.

BACKGROUND: Independent risk factors for abdominal aortic aneurysm (AAA) have not been clearly defined in multivariable analyses of large patient populations. OBJECTIVE: To identify factors that are independently associated with AAA and to determine the prevalence of previously unrecognized AAA in defined demographic and risk groups. DESIGN: Cross-sectional screening study. SETTING: 15 Department of Veterans Affairs medical centers. PARTICIPANTS: 73451 veterans who were 50 to 79 years of age and had no history of AAA. MEASUREMENTS: The results of ultrasonographic screening for AAA and a prescreening questionnaire were analyzed using multiple logistic regression. RESULTS: An AAA of 4.0 cm or larger was detected in 1031 participants (1.4%). Smoking was the risk factor most strongly associated with AAA; the odds ratio (OR) for AAAs of 4.0 cm or larger compared with normal aortas (infrarenal aortic diameter < 3.0 cm) was 5.57 (95% CI, 4.24 to 7.31). The association between smoking and AAA increased significantly with the number of years of smoking and decreased significantly with the number of years after quitting smoking. The excess prevalence associated with smoking accounted for 78% of all AAAs that were 4.0 cm or larger in the study sample. Female sex (OR, 0.22 [CI, 0.07 to 0.68]), black race (OR, 0.49 [CI, 0.35 to 0.69]), and presence of diabetes (OR, 0.54 [CI, 0.44 to 0.65]) were negatively associated with AAA. A family history of AAA was positively associated with AAA (OR, 1.95 [CI, 1.56 to 2.43]) but was reported by only 5.1% of participants. Other independently associated factors included age, height, coronary artery disease, any atherosclerosis, high cholesterol levels, and hypertension. CONCLUSIONS: Abdominal aortic aneurysm is associated with multiple factors. Smoking was the risk factor most strongly associated with AAA and may be responsible for most clinically important cases of previously undiagnosed AAA.

Aged↗
PubMed1997

Relationship of age, gender, race, and body size to infrarenal aortic diameter. The Aneurysm Detection and Management (ADAM) Veterans Affairs Cooperative Study Investigators.

PURPOSE: To assess the effects of age, gender, race, and body size on infrarenal aortic diameter (IAD) and to determine expected values for IAD on the basis of these factors. METHODS: Veterans aged 50 to 79 years at 15 Department of Veterans Affairs medical centers were invited to undergo ultrasound measurement of IAD and complete a pre-screening questionnaire. We report here on 69,905 subjects who had no previous history of abdominal aortic aneurysm (AAA) and no ultrasound evidence of AAA (defined as IAD > or = 3.0 cm). RESULTS: Although age, gender, black race, height, weight, body mass index, and body surface area were associated with IAD by multivariate linear regression (all p < 0.001), the effects were small. Female sex was associated with a 0.14 cm reduction in IAD and black race with a 0.01 cm increase in IAD. A 0.1 cm change in IAD was associated with large changes in the independent variables: 29 years in age, 19 cm or 40 cm in height, 35 kg in weight, 11 kg/m2 in body mass index, and 0.35 m2 in body surface area. Nearly all height-weight groups were within 0.1 cm of the gender means, and the unadjusted gender means differed by only 0.23 cm. The variation among medical centers had more influence on IAD than did the combination of age, gender, race, and body size. CONCLUSIONS: Age, gender, race, and body size have statistically significant but small effects on IAD. Use of these parameters to define AAA may not offer sufficient advantage over simpler definitions (such as an IAD > or = 3.0 cm) to be warranted.

Aged↗
PubMed1997

Extrahepatic ischemia-reperfusion injury reduces hepatic oxidative drug metabolism as determined by serial antipyrine clearance.

PURPOSE: All transplanted solid organs experience some degree of ischemia-reperfusion (I-R) injury. This I-R injury can contribute to graft dysfunction which stems in part from the acute phase response and a resultant host of cytokines. Recent evidence suggests that organs remote to the site of I-R injury can be affected by circulating cytokines originating from these I-R injuries. Since many of these acute phase cytokines inhibit hepatic cytochrome P-450 (CYP) enzymes, we chose to investigate whether extrahepatic I-R injuries could influence hepatic oxidative drug metabolism. METHODS: Fifteen dogs were divided into three surgical groups: (I) sham I-R; (II) bilateral normothermic renal I-R; and (III) normothermic intestinal I-R. Antipyrine (AP) was selected as a model substrate and administered intravenously at a dose of 10 mg/kg. AP serum concentrations were determined by HPLC and cytokine activity (IL-1, IL-6, and TNFalpha) was measured via bioassay. Serial AP clearance and serum cytokine concentrations were determined 3 days prior to and at 4 hr, 24 hr, 3 days and 7 days after surgery. Hematology and blood chemistries were monitored throughout the study period. RESULTS: AP clearance was significantly reduced in groups II and III at 4 and 24 hrs post-l-R injury, while AP binding and apparent volume of distribution were unaffected. Peak levels of TNF and IL-6 activity occurred at 1 and 4 hours, respectively. IL-I activity was not detected in any group. AP clearance correlated strongly to circulating levels of IL-6 (r = -0.789, p = 0.0002). CONCLUSIONS: Our findings indicate that extrahepatic I-R injury can affect hepatic oxidative drug metabolism and this effect is mediated in part by circulating cytokines.

Animals↗
PubMed1997

Metabolic activation of aromatic amines by human pancreas.

Epidemiologic studies have suggested that aromatic amines (and nitroaromatic hydrocarbons) may be carcinogenic for human pancreas. Pancreatic tissues from 29 organ donors (13 smokers, 16 non-smokers) were examined for their ability to metabolize aromatic amines and other carcinogens. Microsomes showed no activity for cytochrome P450 (P450) 1A2-dependent N-oxidation of 4-aminobiphenyl (ABP) or for the following activities (and associated P450s): aminopyrine N-demethylation and ethylmorphine N-demethylation (P450 3A4); ethoxyresorufin O-deethylation (P450 1A1) and pentoxyresorufin O-dealkylation (P450 2B6); p-nitrophenol hydroxylation and N-nitrosodimethyl-amine N-demethylation (P450 2E1); lauric acid omega-hydroxylation (P450 4A1); and 4-(methylnitrosamino)-1-(3-pyridyl-1-butanol) (NNAL) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) alpha-oxidation (P450 1A2, 2A6, 2D6). Antibodies were used to examine microsomal levels of P450 1A2, 2A6, 2C8/9/18/19, 2E1, 2D6, and 3A3/4/5/7 and epoxide hydrolase. Immunoblots detected only epoxide hydrolase at low levels; P450 levels were <1% of liver. Microsomal benzidine/prostaglandin hydroperoxidation activity was low. In pancreatic cytosols and microsomes, 4-nitrobiphenyl reductase activities were present at levels comparable to human liver. The O-acetyltransferase activity (AcCoA-dependent DNA-binding of [3H]N-hydroxy-ABP) of pancreatic cytosols was high, about twothirds the levels measured in human colon. Cytosols showed high activity for N-acetylation of p-aminobenzoic acid, but not of sulfamethazine, indicating that acetyltransferase-1 (NAT1) is predominantly expressed in this tissue. Cytosolic sulfotransferase was detected at low levels. Using 32P-post-labeling enhanced by butanol extraction, putative arylamine-DNA adducts were detected in most samples. Moreover, in eight of 29 DNA samples, a major adduct was observed that was chromatographically identical to the predominant ABP-DNA adduct, N-(deoxyguanosin-8-yl)-ABP. These results are consistent with a hypothesis that aromatic amines and nitroaromatic hydrocarbons may be involved in the etiology of human pancreatic cancer.

Acetyltransferases↗
PubMed1997

Pneumoappendix after an inversion appendectomy: an unreported radiologic finding.

Radiographically detectable gas only occasionally fills the lumen of the vermiform appendix (pneumoappendix), and the diagnostic significance of this gas remains unresolved in the radiologic literature. The following case report is a previously unreported finding of a postoperative plain abdominal radiograph showing a dilated pneumoappendix after an inversion-ligation appendectomy. A brief review of the surgical technique is included to help explain these radiographic findings.

Adult↗
PubMed1996

Young women with advanced aortoiliac occlusive disease: new insights.

We identified a group of 24 young (less than 50 years of age) women with isolated, premature atherosclerotic aortoiliac occlusive disease and attempted to identify distinguishing hemostatic characteristics. Most of these patients (62%) presented with acute thromboembolic events (blue toe syndrome, n = 6; macroemboli, n = 6; or aortoiliac thrombosis, n = 3). Aortoiliac reconstruction (aortoiliac endarterectomy, n = 10, aortobifurcation bypass grafts, n = 6; and percutaneous angioplasty, n = 4) was complicated by early thrombosis in 6 of 20 cases (30%), (1 of 10 endarterectomies, 4 of 6 bypass grafts, and 1 of 4 angioplasties). Fresh thrombus overlying an atherosclerotic plaque was a common finding at surgery. This observation and the relatively high incidence of thromboembolic events led us to hypothesize that a characteristic hemostatic profile might underlie the remarkably similar clinical presentations of these women. Levels of antiphospholipid antibodies (anticardiolipin antibodies and lupus anticoagulant), plasminogen activator inhibitor-1, fibrinogen, antithrombin III, protein C, protein S, plasminogen, prothrombin fragment F1 + 2, and D-dimer were determined for these young women and for 21 age-matched white female control subjects without vascular disease and nine white male patients with aortoiliac occlusive disease (mean 61 years, range 43 to 74 years). The incidence of anticardiolipin antibodies was 42% (8 of 19) in the female patients, which was significantly elevated (p = 0.028). The female (62.5%) and male (100%) patients had significantly elevated D-dimer levels (p < 0.001). Deficiencies of antithrombin III, protein C, and protein S were rare. A unique pattern of premature aortoiliac atherosclerosis exists in some young women. Intra-arterial thromboembolic events are common at presentation and complicate surgical management. The role of antiphospholipid antibodies remains uncertain.

Adult↗
PubMed1996

Can the NASCET technique for measuring carotid stenosis be reliably applied outside the trial?

PURPOSE: The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Artery Study (ACAS) both confirmed the effectiveness of carotid endarterectomy for preventing stroke in patients who have significant carotid stenosis. A uniform technique for measuring carotid stenosis from an arteriogram (% stenosis = [1 - minimum residual lumen/normal distal cervical internal carotid artery diameter] x 100) was used in both trials, with reproducibility internally validated. The reliability of this measurement when used outside the trials for defining carotid stenosis has not been validated. Imprecise calculation of carotid stenosis can result in a 50% overestimation of significant carotid disease and potential overuse of carotid surgery. This is a prospective study of the reliability of carotid stenosis measurements performed by practicing physicians of different specialties and different levels of clinical experience. METHODS: Two vascular surgeons and two interventional radiologists (one resident and one staff member per specialty), blinded to results, calculated the percent stenosis from 219 consecutive arteriograms performed to evaluate extracranial carotid artery occlusive disease; 72 random films were reread by each individual. The interpretations were grouped as < 60% or > or = 60% stenosis (ACAS) and as < 30%, 30% to 69%, and > or = 70% stenosis (NASCET). Interobserver and intraobserver agreement were analyzed with the kappa statistic and Pearson correlation coefficients. RESULTS: Interobserver reliability in categorizing carotid stenosis revealed excellent agreement for both ACAS (kappa = 0.825 to 0.903) and NASCET groups (kappa = 0.729 to 0.793). Interobserver correlation coefficients ranged from 0.91 to 0.95. Intraobserver agreement was also highly reproducible for both the ACAS (kappa = 0.732 to 0.970) and NASCET categories (kappa = 0.634 to 0.805). Intraobserver correlation coefficients ranged from 0.89 to 0.95. CONCLUSION: The NASCET technique for quantification of carotid stenosis can be easily learned by physicians and reliably implemented for appropriate identification of candidates for carotid endarterectomy.

Angiography, Digital Subtraction↗
PubMed1996

Primary Clostridium septicum aortitis: a rare cause of necrotizing suprarenal aortic infection. A case report and review of the literature.

A 74-year old woman sought medical attention for general symptoms of nausea, vomiting, and back pain. A computed tomographic scan showed gas in the wall of the descending thoracic and suprarenal aortas. Emergency thoracoabdominal exploration revealed a necrotizing infection of the thoracic aorta extending to the origin of the celiac axis. After surgery Clostridium septicum was identified in tissue culture. Surgical management consisted of in-situ graft replacement of the thoracoabdominal aorta. Three months later, a pseudoaneurysm developed at the distal anastomosis. The patient refused further surgery and died 3 days later. The cause of death was presumed to be a ruptured mycotic aneurysm as a result of recurrent C. septicum infection. The relationship of C. septicum with occult gastrointestinal and hematologic malignancy has been documented. This patient represents the 10th reported case of C. septicum arteritis. Including the nine previous case reports of C. septicum arteritis, the mortality rate is 70%. When evaluating a patient with a mycotic aneurysm or aortitis, C. septicum should be considered. If it is found, a search should be carried out for an associated gastrointestinal or hematologic malignancy. Surgical repair should include extraanatomic revascularization and wide debridement of the infected field. Consideration should be given to lifelong antimicrobial therapy for this potentially fatal infection.

Aged↗
PubMed1996

Candida arteritis: are GI endoscopic procedures a source of vascular infections?

A 53-year-old woman, 11 years after a renal transplant on chronic immunosuppression, presented with a sudden onset of a painless left groin mass. Ultrasound revealed a 3 cm common femoral artery pseudoaneurysm and a 3 cm saccular aneurysm of the infrarenal aorta. Operative repair was excision and patch angioplasty of the aortic aneurysm with internal iliac artery and interposition grafting of the femoral artery aneurysm with saphenous vein. Postoperatively, Candida albicans was identified in the aortic and common femoral arterial cultures. Candida infections often occur in patients with impaired cellular immunity due to seeding from urinary tract infections, vascular catheters, or manipulation of the gastrointestinal tract. Our patient, without any prior history of a fungal infection, had undergone a colonoscopy 3 weeks earlier. Without any other possible source being identified, the proposed mechanism for fungal entry into the vascular system was via the gastrointestinal tract, with seeding from the portal venous system. The exact medical and surgical management of these patients remains undefined, and a transplant vascular registry is really needed. However, immunocompromised solid organ transplant recipients undergoing gastrointestinal endoscopic procedures may be at a greater risk for the development of subsequent septicemia. Further reports are really needed to confirm the possible need in these patients for both periprocedural antibiotic and antifungal prophylactic coverage.

Aneurysm, Infected↗
PubMed1996

Combined kidney and pancreas transplants through lower transverse abdominal incisions.

Improvements in the surgical aspects of combined kidney and pancreas transplants have resulted in better overall graft and patient survival. Pancreas transplants were initially performed through lower transplant flank incisions opposite the kidney. However, because of high wound complication rate, most centers now perform pancreas transplants through lower midline incisions. We retrospectively reviewed our experience in 40 combined kidney and pancreas transplant recipients with an initial group of 6 midline incisions and 34 later lower transverse abdominal incisions. The number of midline incisions was too small to make a direct comparison, but our series of patients with transverse incisions was compared with the reported literature using a midline incision. The overall infectious and hernia rates for the transverse incision were 12% and 6% respectively which are both very acceptable. The average operative time was 5.5 h. The transverse incision may be associated with less pain, shorter ileus, and fewer pulmonary complications. A lower transverse incision has the major advantage of excellent exposure directly over the iliac vessels and is our incision of choice.

Adult↗
PubMed1996

Prophylactic wound antibiotics for combined kidney and pancreas transplants.

For combined kidney and pancreas transplant recipients infectious complications remain a major source of morbidity. With as many antibiotic protocols as transplant centers, the exact type and duration for prophylactic wound antibiotics remains undefined. A retrospective review of our series of 40 combined kidney and pancreas transplants was performed using a single 1 g dose of cefazolin preoperatively along with cefazolin bladder and intra-abdominal irrigation. Two patients developed superficial wound infections for a rate of 5% (2/37). The deep wound infection rate was 11% (4/37), and all followed either a bladder anastomotic leak or the initial development of transplant pancreatitis. Our overall rate of 16% is very comparable with other series of combined kidney and pancreas transplant recipients. To help eliminate the potential development of superinfections and resistant organisms, a single dose of antibiotics appears to be as effective for wound prophylaxis in these patients when compared to multiple-antibiotic and multiple-day regiments. A randomized prospective study of prophylactic antibiotics in combined kidney and pancreas transplants is needed.

Adult↗