Search PubMed⌕ Search

Biomedical subjects

Stevan B Streem

Publications and source records attributed to Stevan B Streem.

26 records · Page 2Linked to original sources

Ureteroscopic laser endopyelotomy: a single-center experience.

PURPOSE: We review our experience with ureteroscopic endopyelotomy using a holmium laser for correction of ureteropelvic junction (UPJ) obstruction in order to further define the immediate and long-term results and complications. PATIENTS AND METHODS: From 1999 to 2002, 11 men and 34 women (mean age 42 years) underwent 46 ureteroscopic holmium laser endopyelotomy procedures for treatment of primary (N=40) or secondary (N=5) UPJ obstruction. The inclusion criteria were a short (<2-cm) obstruction and absence of ipsilateral renal calculi. Demographic, intraoperative, and postoperative measures were obtained from a prospectively designed and updated database. The endopyelotomy was performed under direct vision using a semirigid (N=40) or flexible (N=5) ureteroscope with a laser setting of 1 J at 10 Hz. Radiographic confirmation of obstruction and the results of intervention was obtained by combinations of intravenous and diuretic urography, diuretic renography, ultrasonography, and CT. The first postoperative and latest radiographic follow-up studies were compared with the preoperative studies to determine whether the obstruction was resolved, unchanged, or worsened. Success was defined as symptomatic relief and radiographic resolution. RESULTS: The mean operative time was 65 minutes (range 10-153 minutes). There were no intraoperative complications, although 5 patients (11.1%) experienced postoperative complications consisting of subcapsular hematoma, pyelonephritis, sepsis, urinary retention, or dysrhythmia. Forty-two patients (93%) had a hospital stay of <23 hours. Stents were removed 3 to 8 weeks (mean 5 weeks) postoperatively. The mean length of follow-up was 23.2 months (range 5-43 months). Symptoms were resolved in 65.4% of patients, improved in 7.7%, unchanged in 11.5%, and worse in 15.4%. Radiographically, at latest follow-up, the obstruction was resolved in 73.1% of patients, unchanged in 23.1%, and worse in 3.8%. Primary UPJ obstruction was associated with a symptomatic success rate of 68% compared with only 50% for secondary UPJ obstruction. CONCLUSIONS: Ureteroscopic laser endopyelotomy is a minimally invasive, short-stay outpatient procedure associated with a 65.4% symptomatic and 73.1% radiographic success rate. In contrast to the findings in previous reports of results of retrograde or antegrade endopyelotomy, patients treated for primary UPJ obstruction experienced higher rates of success than those with secondary obstruction.

Adolescent↗

Laparoscopic radical nephrectomy: incorporating advantages of hand assisted and standard laparoscopy.

PURPOSE: We present an approach to laparoscopic radical nephrectomy and intact specimen extraction, which incorporates hand assisted and standard laparoscopic techniques. MATERIALS AND METHODS: A refined approach to laparoscopic radical nephrectomy is described and our experience is reviewed. A low, muscle splitting Gibson incision is made just lateral to the rectus muscle and the hand port is inserted. A trocar is placed through the hand port and pneumoperitoneum is established. With the laparoscope in the hand port trocar 2 additional trocars are placed under direct vision. The laparoscope is then repositioned through the middle trocar and standard laparoscopic instruments are used through the other 2 trocars including the one in the hand port. If at any time during the procedure the surgeon believes the hand would be useful or needed, the trocar is removed from the hand port and the hand is inserted. RESULTS: This approach has been applied to 7 patients. Mean estimated blood loss was 200 cc (range 50 to 300) and mean operative time was 276.7 minutes (range 247 to 360). Mean specimen weight was 767 gm. (range 538 to 1,170). Pathologically 6 specimens were renal cell carcinoma (grades 2 to 4) and 1 was oncocytoma. Mean length of hospital stay was 3.71 days (range 2 to 7). There were no major complications. CONCLUSIONS: We believe that this approach enables the surgeon to incorporate the advantages of the hand assisted and standard laparoscopic approaches.

Blood Loss, Surgical↗

Computerized tomography guided access for percutaneous nephrostolithotomy.

PURPOSE: Access for percutaneous nephrostolithotomy (PNL) using conventional fluoroscopic guidance may carry an increased risk of damage to surrounding organs in patients with renal calculi and aberrant anatomy. In these situations cross-sectional anatomical imaging may facilitate safe percutaneous access. We describe our experience with computerized tomography (CT) guided percutaneous access for such patients undergoing PNL. MATERIALS AND METHODS: Between June 2000 and December 2001, 154 patients underwent PNL at our institution. Five of these patients (3%) required a total of 6 percutaneous access tracks under CT guidance. All patients in this group had anatomical abnormalities precluding standard access to the collecting system without risk to adjacent organs. These abnormalities included a retrorenal colon in 2 and a severely distorted body habitus due to spinal dysraphism in 3. RESULTS: Percutaneous access was achieved without complication in all cases. At subsequent PNL 5 of the 6 renal units (83%) were rendered completely stone-free. CONCLUSION: CT guided percutaneous access is infrequently required for PNL. However, there is a select group of patients with anatomical anomalies that may predictably require this procedure to facilitate safe and efficacious PNL.

Adult↗

Office-based cystoureteroscopy for assessment of the upper urinary tract.

Nephron-sparing management of malignant or benign lesions of the upper tracts creates the need for surveillance. This usually requires serial endoscopic assessment in the operating room under general anesthesia. Herein is presented a novel alternative to follow selected patients in the office setting using readily available adult cystoscopic equipment.

Ambulatory Care↗

Evolving management of upper-tract transitional-cell carcinoma at a tertiary-care center.

BACKGROUND AND PURPOSE: Traditional management of upper-tract transitional-cell carcinoma (TCC) has been open nephroureterectomy. Minimally invasive options, including laparoscopic and endoscopic techniques, are being applied with increasing frequency, however. To assess the impact of these techniques on the current management of upper-tract TCC, we reviewed our experience managing this problem over the last 3 years. PATIENTS AND METHODS: Since January 1998, 84 patients underwent definitive management of upper-tract TCC using open, laparoscopic, or endoscopic techniques. This study group includes 57 men and 27 women with a mean age of 69.9 years. RESULTS: Fifty-three patients (63.9%) were treated by laparoscopic nephroureterectomy. Twelve patients (14.5%) were treated endoscopically, with percutaneous resection in 7 patients and ureteroscopic resection in 5 patients. The indications for nephron-sparing management in these 12 patients included solitary kidneys in 6 patients, significant comorbidities in 4 patients, and bilateral disease in 1 patient. Endoscopic management was elective in one patient. Nineteen patients (22.9%) underwent open surgical procedures consisting of nephroureterectomy in 16 patients and distal ureterectomy with reimplantation in 3 patients. CONCLUSIONS: Advances in laparoscopy and endourology are significantly impacting the definitive management of upper-tract TCC. Patients with a normal contralateral kidney are currently offered laparoscopic nephroureterectomy, while those with an absent or functionally compromised contralateral kidney are generally managed with endoscopic resection. Although minimally invasive techniques have demonstrated advantages regarding postoperative pain, hospital stay, and return to regular activities, only critical long-term follow-up regarding rates of local and distant recurrence will determine the ultimate role of these techniques.

Aged↗

Laparoscopic management of caliceal diverticular calculi.

PURPOSE: We describe laparoscopic techniques for the definitive management of symptomatic caliceal diverticular stone disease. MATERIALS AND METHODS: Five patients underwent retroperitoneoscopic management of a symptomatic, stone bearing caliceal diverticulum. Techniques for intraoperative localization of the stone bearing diverticulum included retrograde injection of indigo carmine, fluoroscopy and/or laparoscopic ultrasound. In 2 cases the patent neck of the diverticulum was sutured via laparoscopy. RESULTS: Complete stone clearance and obliteration of the diverticular cavity was achieved in all cases without any open conversion. Mean operative time was 133.8 minutes. Mean estimated blood loss was less than 50 cc in 4 cases and 150 cc in 1. Mean hospital stay was 36 hours. There were no laparoscopic or postoperative complications. CONCLUSIONS: The laparoscopic approach to symptomatic caliceal diverticula represents an effective and minimally invasive modality for complete clearance of the stone burden and definitive management of the anatomical abnormality. However, patient selection is paramount. We reserve the laparoscopic approach for symptomatic caliceal diverticula with thin overlying renal parenchyma, or for anterior lesions inaccessible to or unsuccessfully managed by endourological techniques. A decision tree algorithm for managing symptomatic caliceal diverticular calculi is proposed.

Adult↗

The impact of cystinuria on renal function.

PURPOSE: Patients with cystinuria frequently have recurrent renal calculi and may subsequently require multiple stone removing procedures during their lifetime which could have an impact on overall renal function. We determined the potential impact of cystinuria and cystine stone formation on the level of renal function compared to calcium oxalate stone formers. MATERIALS AND METHODS: Clinical data on 40 cystinuric patients followed at 2 medical centers and 45 such individuals in a large stone population data base were analyzed. These results were compared to data on 3,964 calcium oxalate stone formers enrolled in this data base. RESULTS: Mean serum creatinine plus or minus standard deviation for stone forming cystinuric patients was significantly higher than that of the calcium oxalate cohort (1.13 +/- 0.28 versus 1.01 +/- 0.28 mg./100 ml., p = 0.0001). A significantly greater percentage of cystinuric patients (5.8%) had an abnormally increased serum creatinine compared to the calcium oxalate stone formers (2.2%, p = 0.046). Male gender, increasing number of open surgical stone removing procedures and nephrectomy were significant variables associated with an increased serum creatinine (p = 0.0010, p = 0.0038, p = 0.0133, respectively). An increasing number of open surgical stone removing procedures had a significant positive correlation with performance of nephrectomy in the cystinuric population (p = 0.0166). A significantly greater percentage of cystinuric patients compared to the calcium oxalate cohort were subjected to nephrectomy (14.1% versus 2.9%, p = 0.007). CONCLUSIONS: Cystinuric patients have higher serum creatinine levels than calcium oxalate stone formers and they are at more risk for renal loss. When stone removal is required, a minimally invasive approach is preferred.

Adolescent↗