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Biomedical subjects

R E Sosa

Publications and source records attributed to R E Sosa.

At least 19 recordsLinked to original sources
PubMed2000

Ureteroscopic biopsy of upper tract urothelial carcinoma: improved diagnostic accuracy and histopathological considerations using a multi-biopsy approach.

PURPOSE: We assessed the diagnostic accuracy of a ureteroscopic multi-biopsy approach to upper tract urothelial carcinoma compared with subsequently resected surgical specimens. MATERIALS AND METHODS: From 1990 to 1998, 45 upper tract lesions were ureteroscopically evaluated and biopsied with 3Fr cup forceps and/or an 11.5Fr resectoscope before nephroureterectomy or ureterectomy. A definitive diagnosis of urothelial carcinoma was made by biopsy in 40 lesions (89%). Each tumor was histopathologically graded but only staged if the lamina propria were uninvolved (Ta), and if the lamina propria were invaded by tumor (T1+). RESULTS: Of the 40 urothelial tumors 16 (40%) were in the renal pelvis, and 8 (20%) in the proximal and 16 (40%) in the distal ureter. Of the lesions 95% were papillary and 65% were grade 2. Ureteroscopic biopsy grade matched surgical pathological grade in 31 of the 40 cases (78%), and was less than surgical pathological grade in the remainder. Lamina propria was detected in 27 of the 40 biopsies, including 21 of the 34 cup (62%) and all 6 resection loop (100%) biopsies. Ureteroscopic biopsy staging in 27 cases revealed Ta and T1+ disease in 22 and 5, respectively. In the 5 cases in which ureteroscopic biopsy stage was T1+ surgical pathological stage was also pT1+ (range pT1 to pT3). Tumors were pathologically up staged to pT1+ (range pT1 to pT3) in 10 of the 22 cases (45%) in which ureteroscopic biopsy stage was Ta. Tumor location did not affect diagnostic accuracy. CONCLUSIONS: This multi-biopsy ureteroscopic approach provided the tissue diagnosis of urothelial carcinoma in 89% of cases and predicted exact histopathological grade in 78%. Although it is not accurate as a staging modality, multi-biopsy ureteroscopy may assess lamina propria invasion in two-thirds of cases.

Aged↗
PubMed2000

Survey of neuromuscular injuries to the patient and surgeon during urologic laparoscopic surgery.

OBJECTIVES: Laparoscopy may be complicated by neuromuscular injuries, both to the patient and to the surgeon. We used a survey to estimate the incidence of these injuries during urologic laparoscopic surgery, to assess risk factors for these injuries, and to determine preventive measures. METHODS: A survey of neuromuscular injuries associated with laparoscopy submitted to 18 institutions in the United States was completed by 18 attending urologists from 15 institutions. RESULTS: From among a total of 1651 procedures, there were 46 neuromuscular injuries in 45 patients (2.7%), including abdominal wall neuralgia (14), extremity sensory deficit (12), extremity motor deficit (8), clinical rhabdomyolysis (6), shoulder contusion (4), and back spasm (2). Neuromuscular injuries were twice as common with upper retroperitoneal as with pelvic laparoscopy (3. 1% versus 1.5%). Among patients with neuromuscular injuries, those with rhabdomyolysis were heavier (means 91 versus 80 kg) and underwent longer procedures (means 379 versus 300 minutes), and those with motor deficits were older (means 51 versus 42 years of age). Of the surgeons, 28% and 17% reported frequent neck and shoulder pain, respectively. CONCLUSIONS: Although not common, neuromuscular injuries during laparoscopy do contribute to morbidity. Abdominal wall neuralgias, injuries to peripheral nerves, and joint or back injuries likely occur no more frequently than during open surgery, but risk of rhabdomyolysis may be increased. Positioning in a partial rather than full flank position may reduce the incidence of some injuries. Measures to reduce neuromuscular strain on the surgeon during laparoscopy should be considered.

Abdominal Muscles↗
PubMed1999

Lateral transperitoneal laparoscopic adrenalectomy.

Several laparoscopic approaches to the adrenal gland have been described. The lateral transperitoneal approach has several distinct advantages when contrasted with other techniques for laparoscopic adrenalectomy (LA). We present our technique and results obtained in 50 consecutive transperitoneal LAs. We review 50 consecutive laparoscopic adrenalectomies (28 female, 19 male) performed from 1993 to 1998 S.J. Shichman or R.E. Sosa was either the primary surgeon or the first assistant for all cases. The lateral transperitoneal approach described below was used in all cases. Indications for adrenalectomy included Cushing's syndrome (13), aldosteronoma (15), pheochromocytoma (7), nonfunctioning adenoma (11), hyperplasia (2), and 1 case each of Carney's syndrome and metastasis to the adrenal gland. We performed 5 bilateral, 22 left, and 18 right laparoscopic adrenalectomies. The average time needed for bilateral adrenalectomy was 503 min (range 298-690 min); for left adrenalectomy, 227 min (range 121-337 min); and for right LA, 210 min (range 135-355 min). We demonstrated a yearly trend in lower operative times. The largest adrenal gland removed measured 13.8 x 6.7 x 3.5 cm. Intraoperative blood loss was low. Only one patient received a blood transfusion. Conversion to open adrenalectomy was not required. Postoperative analgesic requirements were low. The average length of stay was 3.8 days for bilateral LA and 3 days for unilateral LA. Complications occurred in 5 patients (2 wound infections, 2 hematomas, and 1 pleural effusion). There was no mortality. Lateral transperitoneal adrenalectomy is a safe and efficient technique for the removal of functional and nonfunctional adrenal masses. This technique is associated with low morbidity, a minimal postoperative analgesic requirement, and a short hospital stay and, in our opinion, is more versatile than the retroperitoneal approach.

Adrenal Gland Neoplasms↗
PubMed1999

Acute and chronic interstitial cryotherapy of the adrenal as a treatment modality.

Adrenalectomy is indicated for patients with large adrenal lesions or functional tumors. Cryoablation is currently used as a surgical alternative for the treatment of prostate, lung, brain, pharynx, and liver tumors. The purpose of this study was to determine if cryosurgery could be delivered to small areas in the adrenal gland in a controllable and reproducible manner such that tissue could heal in a nonpathologic way. A total of 14 female mongrel dogs underwent acute (n = 8) or chronic (4 weeks, n = 6) cryoablation using the Cryounit. In the acute study using an open transabdominal approach a 2-mm cryoprobe was placed interstitially into the adrenal tissue, whereas 0.032-inch thermocouples were cannulated into the ipsilateral adrenal artery and vein. Adrenal parenchymal temperature changes were measured using 0.032-inch thermocouples placed at 0.4- and 0.8-cm intervals from the cryoprobe. In the chronic study, cryoablation was achieved by transperitoneal laparoscopic access using a standard laparoscopic technique. Interstitial cryoprobe temperatures decreased from 33.1 +/- 1.9 degrees C to -148 +/- 1.2 degrees C following 15 min of freezing in the acute study. Cryoablation of adrenal tissue achieved temperatures of -41.8 +/- 5.7 degrees C and -21.8 +/- 1 degrees C at distances of 0.4 and 0.8 cm from the cryoprobe, respectively. There was no significant change in adrenazl artery or vein temperatures during cryoablation. Histologically there is a clear demarcation between viable and nonviable tissue characterized by areas of multifocal hemorrhage and pyknosis. After 4 weeks of healing a well-defined line of necrotic and viable tissue is visible. Cryoablation of the adrenal can be delivered in an effective, controllable, and reproducible manner. This controllable energy form may provide a new treatment modality for tissue destruction where adrenal gland preservation is necessary and can be performed by the laparoscopic approach. Understanding the effect of adrenal cryoablation may allow us to treat selected patients with small tumors where organ preservation is necessary.

Adrenal Gland Diseases↗
PubMed1999

Acute and chronic interstitial cryotherapy of the adrenal gland as a treatment modality.

BACKGROUND AND OBJECTIVES: Adrenalectomy is indicated for patients with large adrenal lesions or functional tumors. Cryoablation is currently used as a surgical alternative for the treatment of prostate, lung, brain, pharynx, and liver tumors. The purpose of this study was to determine if cryosurgery could be delivered to small areas in the adrenal gland in a controllable and reproducible manner, so that tissue could heal in a nonpathological way. MATERIALS AND METHODS: Fourteen female mongrel dogs underwent acute (N = 8) or chronic (4 weeks) (N = 6) cryoablation using the Cryounit. In the acute study, using an open transabdominal approach, a 2-mm cryoprobe was placed interstitially into the adrenal tissue, while 0.032-inch thermocouples were cannulated into the ipsilateral adrenal artery and vein. Adrenal parenchymal temperature changes were measured using thermocouples placed at 0.4- and 0.8-cm intervals from the cryoprobe. In the chronic study, cryoablation was achieved by transperitoneal laparoscopic access using standard laparoscopic technique. RESULTS: Interstitial cryoprobe temperatures decreased from 33.1 +/- 1.9 degrees C to -148 +/- 1.2 degrees C following 15 minutes of freezing in the acute study. Cryoablation of adrenal tissue achieved temperatures of -41.8 +/- 5.7 degrees C and -21.8 +/- 1 degrees C at distances of 0.4 and 0.8 cm from the cryoprobe, respectively. There were no significant changes in adrenal artery or vein temperatures during cryoablation. Histologically, there was a clear demarcation between viable and nonviable tissue, the latter being characterized by areas of multifocal hemorrhage and pyknosis. After 4 weeks of healing, there was a well-defined line between necrotic and viable tissue. CONCLUSION: Cryoablation of the adrenal gland can be obtained in an effective, controllable, and reproducible manner. This controllable energy form may provide new modality for tissue destruction where adrenal gland preservation is necessary and can be delivered by the laparoscopic approach. Understanding the effect of adrenal cryoablation may allow us to treat selected patients with small tumors in whom organ preservation is necessary.

Adrenal Glands↗
PubMed1999

Hand-assisted laparoscopic donor nephrectomy versus standard laparoscopic donor nephrectomy: a comparison study in the canine model.

The aim of this study was to compare live donor nephrectomy by hand-assisted laparoscopy to standard laparoscopy in a canine model. Fourteen dogs underwent a left laparoscopic nephrectomy; a standard laparoscopic nephrectomy technique was utilized in seven dogs. In a second group of seven dogs, a hand-assisted laparoscopic technique was used with a Dexterity Pneumo Sleeve hand port. All nephrectomies were performed as "donor" nephrectomies, dividing the vessels last. Total blood loss, operative warm ischemia, time and organ retrieval times were assessed for each group. The average operative time was significantly shorter for hand-assisted laparoscopic donor nephrectomy (32 +/- 8 minutes vs. 61 +/- 8 minutes; p = .02) than for the standard technique. The average warm ischemia (86 +/- 24 seconds vs. 224 +/- 52 seconds; p = .03) and average organ delivery times (4 +/- 3 seconds vs. 45 +/- 9 seconds; p < .01) also were shorter using the hand-assisted laparoscopic technique. No significant differences in average blood loss were found between the two groups (9 +/- 2 cc vs. 6 +/- 1 cc; p = 0.16, NS). Good parenchymal, ureteral, and vascular preservation was achieved by both techniques. Hand-assisted laparoscopy permits shorter operating times and warm ischemia times than standard laparoscopy in a canine model of donor nephrectomy. Hand assistance makes donor laparoscopic nephrectomy technically easier and significantly quicker to perform. If hand-assisted laparoscopy donor nephrectomy is confirmed to be a rapid and safe technique for removing an intact organ, laparoscopic nephrectomy will be a more widely accepted technique among urologists who participate in living related donor kidney transplantation.

Animals↗
PubMed1996

Oliguria during laparoscopic surgery: evidence for direct renal parenchymal compression as an etiologic factor.

Abdominal insufflation during laparoscopy has been associated with transient oliguria, which abates after desufflation. Direct renal compression evoking a Page kidney effect was proposed as a mechanism. In an effort to confirm this theory, the left kidney was subjected to 15 mm Hg compression in six anesthetized mongrel dogs. For this, a pressure cuff was placed around the kidney excluding the renal hilar structures. The contralateral kidney was left untouched to serve as a control. After a steady-state period, the pressure cuff was inflated to 15 mm Hg for 2 hours. Cuff desufflation was followed by a 1-hour recovery period. Urine output, glomerular filtration rate (GFR), and effective renal blood flow (ERBF) were measured for both kidneys during each clearance period. For the treated kidneys, the mean urine output decreased 63% (P < 0.05) during compression and increased 109% (P < 0.05) after cuff desufflation. The GFR decreased 21% (P < 0.01) during compression and increased 25% (P < 0.05) during recovery. The ERBF decreased 26% (P < 0.05) during compression, and during the 1-hour recovery period, ERBF did not recover to baseline values. For the control kidneys, there were no significant changes in urine output or GFR during the experimental and recovery periods. These data support the view that direct renal parenchymal compression is an important factor in the development of insufflation-induced oliguria. The clinical implications of insufflation-induced oliguria during laparoscopy deserve further investigation.

Animals↗
PubMed1995

Laparoscopic laser-assisted bladder autoaugmentation.

OBJECTIVES: The purpose of this study is to examine the feasibility of performing a laparoscopic bladder autoaugmentation and to assess the urodynamic characteristics of an autoaugmented bladder. METHODS: Laparoscopic bladder autoaugmentation was performed in 9 female canines (20 to 30 kg). Following laparoscopic access to the peritoneal cavity, a midline bladder seromyotomy was performed using the potassium titanyl phosphate 532 nm laser. This produced a large bladder diverticulum. Changes in bladder volume and compliance were quantified over a 3-month period of follow-up. RESULTS: Urodynamic evaluation demonstrated an increase in bladder capacity 6 weeks postoperatively in 8 of 9 dogs, with an average volume increase of 45%. Bladder compliance improved in 7 of 9 dogs with an average increase in compliance of 67%. Three months postoperatively, bladder capacity remained increased in 5 of 9 dogs, with an average increase in volume of only 5.3%. An improvement in compliance was sustained in 5 of 9 animals with an average increase of 13.9%. Laparoscopic exploration revealed grossly normal bladders with adhesions of omentum to the seromyotomy site in all canines and the anterior abdominal wall in 2 of 9 canines. Histologically, the seromyotomy site was devoid of muscle with an intact urothelium and a proliferation of loose connective tissue. CONCLUSIONS: The technique of laparoscopic bladder autoaugmentation can be performed easily in the canine model. Although results at 6 weeks show significant improvement, the longer term, 3-month results were not statistically significant. This technique has the potential to offer a minimally invasive correction for patients with low-capacity, high-pressure bladders that have failed pharmacologic treatment.

Abdominal Muscles↗
PubMed1993

Chromophore enhanced laser welding of canine ureters in vitro using a human protein solder: a preliminary step for laparoscopic tissue welding.

Laser welding of the genitourinary tract has the potential advantage of forming an immediate watertight seal. It may obviate the need for sutures, eliminate the inherent lithogenic reaction to suture, and potentially improve healing. In the current study we employed a KTP-532 laser in vitro to weld canine ureters. Ureters were transected over a stent and immediately repaired using the KTP-532 laser (power density 7.14 W/cm.2, spot size = 0.5 cm.) alone or in combination with different tissue solders. Solders consisted of 40% human albumin alone or with the addition of iron oxide or fluorescein as light absorbing dyes (chromophores). Following the repairs, intraluminal bursting strength and the total energy required to complete the repairs were measured. The KTP laser alone was not able to achieve a satisfactory repair. Successful ureteral repairs were achieved in all solder groups while maintaining ureteral continuity at supraphysiologic pressures.

Anastomosis, Surgical↗
PubMed1993

Laparoscopy.

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Adrenal Gland Neoplasms↗
PubMed1992

Renal divalent cation excretion in secondary hypertension.

1. To determine whether abnormal renal calcium excretion is unique to primary genetic hypertension, blood pressure and 24 h urinary excretion of calcium, magnesium, sodium and creatinine were measured in deoxycorticosterone-saline and two-kidney, one-clip Goldblatt hypertensive rats and in their respective controls on low (0.2%) and high (1.8%) dietary calcium intakes. 2. Calcium supplementation lowered blood pressure (P < 0.05) in deoxycorticosterone-saline rats and in control saline-loaded rats, raised blood pressure in two-kidney, one clip rats, and had no effect in sham-operated control rats. 3. On both diets, calcium excretion was higher in hypertensive than in normotensive rats. The high calcium diet increased urinary calcium excretion in all rats, but the changes in urinary calcium excretion closely paralleled the diet-induced changes in blood pressure. Thus, urinary calcium excretion in deoxycorticosterone-saline animals, in whom calcium lowered blood pressure the most, rose the least (107%). Urinary calcium excretion rose the most in two-kidney, one-clip animals (1113%), whose blood pressure also rose the most. 4. Urinary magnesium excretion was also abnormal in hypertensive rats compared with normotensive rats, falling on the high compared with the low calcium diet in normotensive rats, but not in either hypertensive strain. Furthermore, urinary magnesium excretion was closely linked to urinary calcium excretion in saline-loaded control rats (r = 0.78; P = 0.008), but was dissociated from urinary calcium excretion in deoxycorticosterone-saline rats (r = 0.02; not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Laparoscopy: new applications of an established technique.

The safety and cost-effectiveness of any new procedure is, of course, brought into question in this era of heightened fiscal concerns. In general, a review of initial results with laparoscopic pelvic lymph node dissection appears to reveal sufficient patient benefits to warrant further work with these less invasive techniques. The principal benefits include the following: Decreased patient morbidity, early and latent; Shorter hospitalization; Faster recovery and return to normal daily functions; Equivalent efficacy to open surgical alternatives; Overall cost-effectiveness Cosmetic effect; minimizes loss of body image; Reproducible results. Perfecting the skills necessary for complicated laparoscopic surgery requires a commitment of time and work on the part of the surgeon. This is not a procedure that will be learned by auditing a few cases. Laparoscopic surgery requires diligence in mentally and physically preparing the skills needed for surgery and caution in the application of these skills. Nurses can help to minimize this learning curve by taking an active interest in the current and future practice of laparoscopic surgery and by sharing their knowledge and enthusiasm.

Education, Nursing, Continuing↗
PubMed1990

Relation of plasma renin to end organ damage and to protection of K+ feeding in stroke-prone hypertensive rats.

We studied the effects of regular diet (0.35% NaCl/1.1% potassium), high sodium diet (4% NaCl/0.75% potassium), or high sodium and high potassium diet (4% NaCl/2.11% potassium) on blood pressure, plasma renin activity, renal and cerebrovascular lesions, and incidence of stroke and mortality in male stroke-prone spontaneously hypertensive rats (SHRSP). In the first 4 weeks, the rise in blood pressure was higher in high NaCl than in high NaCl/high potassium or regular diet groups. However, by 8 and 12 weeks, the blood pressure in all three groups was similar. After 4 weeks of diet, plasma renin activity was similar in the three groups (3.4 +/- 0.8, 4.1 +/- 0.9, and 5.2 +/- 1.6 ng/ml/hr, in high NaCl, high NaCl/high potassium, and regular diet groups, respectively) and were not related to sodium excretion. After 8 weeks, plasma renin activity was significantly increased only in the high NaCl group (13.7 +/- 3.7 ng/ml/hr), and by 12 weeks plasma renin activity was significantly higher in the high NaCl group (25.3 +/- 3.6 ng/ml/hr) than in the high NaCl/high potassium (11.1 +/- 2.9 ng/ml/hr) or in the regular diet (7.8 +/- 4.6 ng/ml/hr) groups. Moderate to severe renal vascular lesions were first detected in the high NaCl group by 8 weeks of diet. At 12 weeks, renal vascular damage index (RVDI), estimated histologically, was significantly higher in the high NaCl group (RVDI = 79 +/- 14) than in the high NaCl/high potassium (RVDI = 40 +/- 11) and regular diet (RVDI = 7.8 +/- 4.6) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Angiotensin II-induced atrial natriuretic factor release in dogs is not related to hemodynamic responses.

Angiotensin II (Ang II) and atrial natriuretic factor (ANF) appear to act as functional antagonists in the regulation of fluid and electrolyte homeostasis and blood pressure. To further define the relations between these hormones in vivo, we investigated the effect of low doses of Ang II (1-10 ng/kg/min) on plasma ANF levels. We also evaluated the influence of ANF release on the renal and hormonal responses to ANG II. Studies were performed in anesthetized and conscious instrumented dogs during sustained saline load and converting enzyme inhibition. In the anesthetized dogs, Ang II significantly increased plasma ANF levels and ANF arteriovenous difference without changing either atrial pressures or hematocrit. In both conscious and anesthetized dogs, ANF increases were not correlated with blood pressure responses to Ang II and did not occur in control groups when Ang II was replaced by vehicle. Ang II-induced sodium retention and stimulation of aldosterone production were attenuated, and renin suppression was enhanced in dogs having the largest changes in plasma ANF in response to converting enzyme inhibition or Ang II. These results demonstrate that in volume-replete dogs Ang II can promote ANF release independently of changes in atrial pressures or systemic hemodynamics, suggesting that Ang II may exert a significant modulatory effect on ANF secretion. The results also show significant relations between ANF and renal and adrenal responses to Ang II, which may suggest that, in turn, endogenous ANF modulates the effects of Ang II.

Adrenal Glands↗