Normothermic renal artery perfusion: A comparison of perfusates

Hypothermia and preservative perfusates have been used to decrease ischemic renal injury. This study was performed to identify the preservative function of perfusates independent of the effects of hypothermia. Rats underwent 45 minutes of renal ischemia. Rectal and renal parenchyma temperatures were monitored and maintained within 1° C of normal. Perfusates were University of Wisconsin solution (UW), Euro-Collins solution, normal saline solution, and Ringer's lactate solution. A nonperfused ischemic control and a nonischemic control group were also evaluated. Parameters evaluated included serum creatinine and blood urea nitrogen levels, renal ischemic injury grade, renal weight, and gross appearance of the injured kidney. Rats treated with UW solution were found to have a significantly lower creatinine, blood urea nitrogen, and injury grade than the other three perfused groups. The external gross appearance of the UW-treated kidneys was normal, whereas that of the other groups demonstrated moderate to severe injury. Although the mean right/left renal weight difference of the UW-treated group was lower than that of the other three groups, this was not statistically significant. Under normothermic conditions in rats, UW solution affords significant renal protection from ischemia. Euro-Collins, normal saline, and Ringer's lactate solutions display no significant protective effect.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995.     

Comparison of Tl-201 renal uptake with Tc-99m DTPA angiorenography in patients with hypertension. Measures of renal asymmetry.

Renal uptake of Tl-201 reflects renal perfusion and may have a role in defining renal asymmetry in patients with hypertension who are referred for myocardial scintigraphy. The authors compared two methods of quantitating differential renal uptake of Tl-201, with similar data obtained from the angiographic and renal uptake (RU) phases of Tc-99m DTPA scintigraphy in 35 patients with hypertension. For Tl-201, asymmetry in renal counts was quantitated based on a simple outline technique or on interpolative background subtraction of 5-minute posterior images. Inter-observer and intra-observer variability among duplicate measurements were lower for Tl-201, particularly with interpolative background subtraction, than for Tc-99m DTPA. Renal/background ratios were similar for Tl-201 and RU-phase Tc-99m DTPA images when considering liver, spleen, or inter-renal regions as background; however, paraspinal uptake was relatively higher with Tl-201 (P less than 0.01). Qualitatively, renal asymmetry scores with the two radiotracers agreed (r = 0.89, blinded readings by four observers), although asymmetry was more marked with Tl-201 (P = 0.06). Measurements with Tl-201 agreed with both phases of Tc-99m DTPA (r = 0.96 to 0.98), but interpolative background subtraction systematically yielded greater inter-renal asymmetry than RU (P less than 0.01), reflecting the qualitative impression. Thus, ancillary Tl-201 imaging reflects differences between the kidneys in a fashion similar but not identical to Tc-99m DTPA scintigraphy.     

Validation of fetal cerebellar volume by three-dimensional ultrasonography in Brazilian population

BACKGROUND: To validate the prediction equation of the volume of fetal cerebellum by three-dimensional ultrasonography determined for Taiwan's population in Brazilian population. METHODS: A longitudinal prospective study was performed with 52 normal pregnant women between 20 and 32 weeks. The measurement of fetal cerebellar volume was done by virtual organ computer-aided analysis (VOCAL) method, with a rotation angle of 30 degrees. To establish the correlation of fetal cerebellar volume with gestational age, a polynomial regression analysis was performed, with cerebellar volume as dependent variable and gestational age as independent variable. To compare the prediction equation of the volume of fetal cerebellum in Taiwan's population and the equation established in this study, with the values obtained from Brazilian population (referential), we used the intraclass correlation coefficient, with the averages compared by paired Student's t test. RESULTS: The volume of fetal cerebellum was highly correlated with gestational age, and the best prediction equation obtained was of the second degree. The equation established in this study predicted cerebellar volumes more accurately than the equation established for Taiwan's population, since the average values of fetal cerebellar volume were more similar to the average values of reference. CONCLUSIONS: The equation established for Taiwan's population presented less accuracy in Brazilian population, possibly due to the strong ethnical differences between both populations.     

Application of fibrin glue in microvascular anastomoses: comparative analysis with the conventional suture technique using a free flap model

Background: Several studies have already reported the utilization of fibrin glue in microvascular anastomoses to minimize the number of sutures and to decrease the operative time. Despite the good results obtained in most of these experiments, its clinical application has not launched. The aim of this study was to clarify the controversies around the safeness of fibrin glue application in microvascular anastomoses, and also to demonstrate the potential benefits of fibrin glue application in a realistic free flap model. Methods: Twenty‐seven rabbits were used in this study. The experimental model consisted of a free groin flap transfer to the anterior cervical region. The flap's circulation was restored by means of an end‐to‐side anastomosis between the femoral and carotid arteries, and an end‐to‐end anastomosis between the femoral and external jugular veins. The animals were divided into two groups (n = 10) according to the anastomosis technique: Group I (conventional suture) and group II (fibrin glue). Results: The number of sutures required to complete the arterial and venous anastomoses was reduced in 39 and 37% in group II, respectively. Despite this reduction, the anastomoses maintained adequate patency rates and mechanical strength. Both arterial and venous anastomoses benefited from fibrin glue application, which made them easier and faster to perform. The flaps' ischemic time and the total operative time were also significantly shortened. Conclusions: In this study, the application of fibrin glue in microvascular anastomoses was safe and reliable. The risk‐benefit ratio of fibrin glue application in microvascular anastomoses is favorable for its use. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.     

Bariatric surgery improves cardiac function in morbidly obese patients with severe cardiomyopathy.

BACKGROUND: Longstanding morbid obesity can be associated with severe cardiomyopathy. However, the safety and efficacy of bariatric surgery in patients with severe cardiomyopathy has not been studied, and the effect of surgical weight loss on postoperative cardiac function is also unknown. In addition, morbidly obese patients have significantly increased mortality associated with cardiac transplantation, often precluding them from becoming recipients. METHODS: A retrospective study of patients with a left ventricular ejection fraction < or =35% who underwent bariatric surgery (1998-2005) was performed. Short-term morbidity/mortality, length of stay, excess weight loss, pre- and postoperative left ventricular ejection fraction, and New York Heart Association (NYHA) functional class were assessed. RESULTS: A total of 14 patients (10 men and 4 women) with a mean preoperative body mass index of 50.8 +/- 2.04 kg/m(2) underwent bariatric surgery (10 underwent laparoscopic Roux-en-Y gastric bypass, 1 open Roux-en-Y gastric bypass, 2 sleeve gastrectomy, and 1 laparoscopic gastric banding). The complications were pulmonary edema in 1, hypotension in 1, and transient renal insufficiency in 2. The median length of stay was 3.0 days (range 2-9). The mean excess weight loss at 6 months was 50.4%, with a decrease in the mean body mass index from 50.8 +/- 2.04 kg/m(2) to 36.8 +/- 1.72 kg/m(2). The mean left ventricular ejection fraction at 6 months had significantly improved from 23% +/- 2% to 32% +/- 4% (P = .04), correlating with improved functional capacity, as measured by the NYHA classification. Preoperatively, 2 patients (14%) had an NYHA classification of IV, 6 (43%) a classification of III, and 6 (43%) a classification of II. At 6 months postoperatively, no patient had an NYHA classification of IV, 2 (14%) had a classification of III, and 12 (86%) an NYHA classification of II. Two patients had undergone cardiac transplant evaluations preoperatively and underwent successful transplantation after weight loss. CONCLUSION: The results of our study have shown that bariatric surgery for patients with cardiomyopathy is feasible and effective. Surgically induced weight loss results in both subjective and objective improvement in cardiac function. In addition, surgical weight loss can provide a bridge to transplantation in patients who were prohibited secondary to their morbid obesity.     

Clinical and histologic follow-up after antireflux surgery for Barrett’s esophagus

There are few prospective studies that document the histologic follow-up after antireflux surgery in patients with Barrett’s esophagus, as defined by the recently standardized criteria. We report the clinical, endoscopic, and histologic results of patients with Barrett’s esophagus followed postoperatively for at least 2 years. Diagnosis of Barrett’s esophagus required preoperative endoscopic evidence of columnarlined epithelium in the esophagus and a biopsy demonstrating specialized intestinal metaplasia, which stains positively with Alcian blue stain. Between April 1993 and November 1998, a total of 104 patients meeting these criteria underwent fundoplication (laparoscopic [n = 84] or open [n = 6] nissen, laparoscopic Toupet [n = 11], laparoscopic Collis-Nissen [n = 1], Collins-Toupet [n = 1] or open Dor [n = 1]). Short-segment Barrett’s esophagus (length of intestinal metaplasia <3 cm) was found preoperatively in 34% and low-grade dysplasia in 4% of patients. All patients were contacted yearly by mail, phone, or clinic visit. At a mean follow-up of 4.6 years (range 2 to 7.5 years), 81% of patients had stopped taking antisecretory medications and 97% were satisfied with the results of their operations. Eight patients have undergone reoperation for recurrence of symptoms. Two patients have died and two were excluded from endoscopic biopsy because of portal hypertension. Sixty-six patients complied with the surveillance protocol, and their histologic results were returned to our center. Symptomatic follow-up of the 34 patients who refused surveillance esophagogastro and duodenoscopy revealed two patients who were taking medication for reflux symptoms. None of the patients have developed high-grade dysplasia or esophageal carcinoma during surveillance endoscopy (337 total patient-years of follow-up). The incidence of regression of intestinal metaplasia to cardiac-fundic-type metaplasia after successful antireflux surgery is greater than previously reported. We suspect that this is a result of longer follow-up and the inclusion of patients with short-segment Barrett’s esophagus. A substantial number of patients with Barrett’s esophagus who are asymptomatic after antireflux surgery refuse surveillance endoscopy. Presented at the Forty-Second Annual Meeting of The Society for Surgery of the Alimentary Tract, Atlanta, Georgia, May 20–23, 2001 (oral presentation).     

A New Radiocolloid for Sentinel Node Detection in Breast Cancer

Background:The optimal radioactive tracer and technique for sentinel lymph node localization in breast cancer is yet to be determined. The dilemma of small particle size with dispersion to second echelon nodes versus failure of migration of larger radiocolloids needs to be resolved. A new radiocolloid preparation with particle size under 0.1 micron was developed with excellent primary/post lymphatic entrapment ratio.Objective:To assess the feasibility of a new ^99mTc radiocolloid cysteine-rhenium colloid in sentinel lymph node (SLN) localization for breast cancer.Methods:Forty-seven patients with newly diagnosed T1 or T2 breast cancer underwent injection of ^99mTc-labeled cysteine-rhenium colloid followed by lymphoscintigraphy. Same day SLN biopsy with patent blue dye and intraoperative gamma probe to identify SLNs were performed.Results:SLN mapping and intraoperative localization were successful in 46/47 (98%) of patients. The blue dye radioactive tracer concordance was 94%. There was one false-negative in a patient with a nonpalpable tumor that underwent ultrasound-guided peritumoral radiocolloid injection.Conclusions:^99mTc-cysteine-rhenium colloid is highly effective in identifying SLNs. It has the advantage of smaller particle size than sulfur colloid with easier lymphatic migration. It has a more neutral pH with less pain on injection and does not require filtration, thereby minimizing radiation exposure to technologists.Presented at the 53rd Annual Meeting of the Society of Surgical Oncology, New Orleans, Louisiana, March 16–19, 2000     

Effect of rhBMP‐2 and VEGF in a vascularized bone allotransplant experimental model based on surgical neoangiogenesis

We have demonstrated survival of living allogeneic bone without long‐term immunosuppression using short‐term immunosuppression and simultaneous creation of an autogenous neoagiogenic circulation. In this study, bone morphogenic protein‐2 (rhBMP‐2), and/or vascular endothelial growth factor (VEGF), were used to augment this process. Femoral diaphyseal bone was transplanted heterotopically from 46 Dark Agouti to 46 Lewis rats. Microvascular repair of the allotransplant nutrient pedicle was combined with intra‐medullary implantation of an autogenous saphenous arteriovenous (AV) bundle and biodegradable microspheres containing buffer (control), rhBMP‐2 or rhBMP‐2 + VEGF. FK‐506 given daily for 14 days maintained nutrient pedicle flow during angiogenesis. After an 18 weeks survival period, we measured angiogenesis (capillary density) from the AV bundle and cortical bone blood flow. Both measures were greater in the combined (rhBMP‐2 + VEGF) group than rhBMP‐2 and control groups (p < 0.05). Osteoblast counts were also higher in the rhBMP‐2 + VEGF group (p < 0.05). A trend towards greater bone formation was seen in both rhBMP2 + VGF and rhBMP2 groups as compared to controls (p = 0.059). Local administration of VEGF and rhBMP‐2 augments angiogenesis, osteoblastic activity and bone blood flow from implanted blood vessels of donor origin in vascularized bone allografts. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 561–566, 2013