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Biomedical subjects

Ralph V Clayman

Publications and source records attributed to Ralph V Clayman.

At least 127 records · Page 7Linked to original sources

Comparison of helical computerized tomography and plain radiography for estimating urinary stone size.

PURPOSE: We evaluated the accuracy of noncontrast spiral computerized tomography (CT) for determining urinary stone size compared with plain x-ray. MATERIALS AND METHODS: We retrospectively analyzed noncontrast helical CT and plain x-ray of the kidneys, ureters and bladder images of 39 patients with urolithiasis who underwent each study from July 1997 to February 1999. Stone size on x-ray was measured in the craniocaudal and transverse dimensions by a single radiologist (I.C.B.). The size of the same stone was then determined on blinded noncontrast spiral CT images. Stones that were less than 3 mm. were excluded from study. On CT estimated craniocaudal dimension was based on collimation thickness, the reconstruction interval and the number of images on which the stone was visualized. RESULTS: We evaluated 58 stones 3 mm. or larger in the greatest dimension on plain x-ray of the kidneys, ureters and bladder, and noncontrast spiral CT, including 15 in the distal ureter, 7 in the mid or proximal ureter and 36 in the kidneys. Stone size was 3 to 18 mm. in the greatest dimension. Mean transverse dimension of the stone plus or minus standard deviation on noncontrast spiral CT was 5.1 +/- 1.08 versus 4.9 +/- 1.08 mm. on plain x-ray of the kidneys, ureters and bladder (paired t test; p = 0.335). The mean craniocaudal dimension on noncontrast spiral CT was 7.5 +/- 1.98 versus 6.7 +/- 1.98 mm. on plain x-ray paired t test (p = 0.005). CONCLUSIONS: Noncontrast spiral CT enables a similar measurement of stone size along the transverse dimension as plain x-ray of the kidneys, ureters and bladder. In individuals noncontrast spiral CT does not accurately measure the craniocaudal dimension of stones compared with plain x-ray when standard acquisition and reconstruction techniques are used. In this regard it has a tendency to overestimate stone size by an average of 0.8 mm.

Humans↗

Long-term followup after laparoscopic radical nephrectomy.

PURPOSE: Laparoscopic radical nephrectomy has been shown to be less morbid than traditional open radical nephrectomy. The long-term oncological effectiveness of laparoscopic radical nephrectomy remains to be established. MATERIALS AND METHODS: At 3 centers patients undergoing laparoscopic radical nephrectomy before November 1, 1996 with pathologically confirmed renal cell carcinoma were identified. A representative group of patients undergoing open radical nephrectomy for clinical T1, T2 lesions was also identified. Staging, operative details and postoperative course were reviewed. Followup consisted of review of clinical, laboratory and radiological records. Kaplan-Meier analysis was performed. RESULTS: The study included 64 patients treated with laparoscopic and 69 treated with open radical nephrectomy with respective average ages of 60.6 and 61.3 years at surgery. On preoperative imaging open lesions were larger (6.2 cm., range 2.5 to 15) than laparoscopic radical nephrectomy lesions (4.3 cm., range 2 to 10, p <0.001). Pathology reports revealed no difference in specimen weight (425 and 495 gm., p = 0.146) or average Fuhrman grade (1.88 and 1.78, p = 0.476) between laparoscopic and open radical nephrectomy, respectively. Median followup was 54 months (range 0 to 94) for laparoscopic and 69 months (range 8 to 114) for open radical nephrectomy. Kaplan-Meier analysis with log rank comparison revealed 5-year recurrence-free survival of 92% and 91% for laparoscopic and open radical nephrectomy, respectively (p = 0.583). At 5 years cancer specific survival was 98% and 92% (p = 0.124), and nonspecific survival was 81% and 89% (p = 0.260) for laparoscopic and open radical nephrectomy, respectively. CONCLUSIONS: Laparoscopic radical nephrectomy confers long-term oncological effectiveness equivalent to traditional open radical nephrectomy.

Carcinoma, Renal Cell↗

Hydrophilic guide wire technique to facilitate organ entrapment using a laparoscopic sack during laparoscopy.

PURPOSE: Morcellation of the kidney in a LapSac (Cook Surgical, Spencer, Indiana) is reportedly safe and effective during laparoscopic nephrectomy. However, organ entrapment in a LapSac can be difficult, especially during early surgeon experience. A technique to facilitate organ entrapment is described. MATERIALS AND METHODS: We have recently used a simple technique to facilitate deployment of the LapSac in the abdomen using a hydrophilic nitinol guide wire passed through the holes in the mouth of the sack beside its drawstring. The inherent elasticity of the guide wire helps to spring open the mouth of the sack, while facilitating appropriate orientation of the sack mouth. RESULTS: This technique appears to decrease the time needed for organ entrapment because it eliminates the need to triangulate the sack to achieve organ entrapment. An additional port is usually not required during the procedure. CONCLUSIONS: The hydrophilic guide wire technique is inexpensive and effective for LapSac deployment and organ entrapment.

Humans↗

Evaluation of the use of a biodegradable ureteral stent after retrograde endopyelotomy in a porcine model.

PURPOSE: We evaluated the use of a poly-L-lactide-co-glycolide (PLGA) bioabsorbable ureteral stent after Acucise balloon incision (Applied Medical Resources, Rancho Santa Magarita, California) endopyelotomy in a porcine model. MATERIALS AND METHODS: After unilateral Acucise endopyelotomy in 9 female Yucatan minipigs a self-reinforced PLGA stent was placed in 5 (group 1) and a 7Fr double pigtail Percuflex stent (Boston Scientific, Natick, Massachusetts) was placed in 4 (group 2). Preoperatively, and 6 and 12 weeks postoperatively plain x-ray of the kidneys, ureters and bladder, cystography, side specific creatinine clearance and retrograde ureterography were done. The contralateral ureters served as untreated controls. The 7Fr stents were removed at 6 weeks. All animals were sacrificed at 12 weeks after bilateral flow studies. Histological specimens from 4 sites along the urinary tract were graded on a healing score of 0-normal, to 3-severe changes. RESULTS: Side specific creatinine clearance was similar to preoperative values at 6 and 12 weeks. At the 2 time points plain x-ray of the kidneys, ureters and bladder in group 1 showed retroperitoneal stent fragments in 3 of the 5 animals, which was confirmed at autopsy. Retrograde ureterography in group 1 showed mild hydronephrosis in all 5 ureters and saccular diverticula in 4, which was similar in 2 and 3 animals, respectively, in group 2. Cystography demonstrated grades 1 to 2 reflux in 2 animals at 6 weeks but none at 12 weeks in group 1 and no reflux at either time point in group 2. Flow rates and healing scores were statistically similar in the 2 groups but the latter trended toward less favorable healing of ureteral musculature with application of the absorbable stent. CONCLUSIONS: In this pilot study the use of self-reinforced PLGA biodegradable ureteral stents was feasible after Acucise endopyelotomy in a porcine model with radiographic and fluid flow results that were relatively similar to those of standard 7Fr stents but with less favorable biocompatibility.

Absorbable Implants↗

Bare naked baskets: ureteroscope deflection and flow characteristics with intact and disassembled ureteroscopic nitinol stone baskets.

PURPOSE: Lower pole renal access during flexible ureterorenoscopy is often limited by the active deflection capabilities of the ureteroscope. Deterioration in the deflection and flow capabilities of ureteroscopes occurs with the passage of instrumentation through the working channel. We performed in vitro evaluation of a novel technique using unsheathed nitinol baskets to minimize the deterioration in deflection and maximize the irrigant flow associated with instrument passage through the working channel during flexible ureterorenoscopy. MATERIALS AND METHODS: Alterations in the irrigant flow and active deflection of 4 ureteroscopes from different manufacturers were evaluated. Each ureteroscope was evaluated with an empty working channel, and then with sheathed and unsheathed 2.2, 3 and 3.2Fr (Cook Urological, Inc., Indianapolis, Indiana), 2.4 and 3Fr (Microvasive Urology, Natick, Massachusetts) nitinol baskets in the working channel. RESULTS: With all baskets tested and in all ureteroscopes the deterioration in active deflection and irrigant flow was improved with the unsheathed baskets. The disassembled basket within the working channel allowed an additional 15 to 20 degrees of active deflection. In addition, the disassembled basket allowed for a 2 to 30-fold increase in irrigant flow compared with an intact basket. CONCLUSIONS: The combination of improved deflection and irrigant flow with this technique may improve ureteroscopic access to lower pole renal calculi.

Alloys↗

Comparison of hand assisted and standard laparoscopic radical nephroureterectomy for the management of localized transitional cell carcinoma.

PURPOSE: Hand assisted laparoscopy affords the surgeon tactile sensation and blunt dissection, which are currently limited using the standard laparoscopic technique. Therefore, we compared standard and hand assisted laparoscopic radical nephroureterectomy for localized upper tract transitional cell carcinoma. MATERIALS AND METHODS: The medical records of 27 patients who underwent standard (11) or hand assisted (16) laparoscopic radical nephroureterectomy between April 1998 and January 2001 were retrospectively reviewed. The parameters of efficacy, efficiency, safety and convalescence were compared. RESULTS: Mean patient age was 64 and 66 years (p = 0.72) in the standard and hand assisted groups, and the mean American Society of Anesthesiologists score was 2.5 and 2.7 (p = 0.64), respectively. All standard and 15 of the 16 hand assisted (94%) procedures were successfully completed via laparoscopy. Total operative time was more than 1 hour shorter for hand assisted than for laparoscopic radical nephroureterectomy (4.9 versus 6.1 hours, p = 0.055). Mean estimated blood loss was similar in the standard and hand assisted groups (190 and 201 ml., p = 0.78). In each group 1 patient required blood transfusion. Mean specimen weight was significantly higher in hand assisted cases (576 versus 335 gm., p = 0.036). Mean time to oral intake was similar in patients who underwent standard and hand assisted laparoscopic radical nephroureterectomy (13 and 20 hours, respectively, p = 0.45). The mean analgesic requirement was also similar (29 and 33 mg. morphine sulfate, respectively, p = 0.83). Mean hospital stay in uncomplicated cases was similar for standard and hand assisted surgery (2.9 and 2.5 days, respectively). Overall hospital stay in the 2 cohorts was also similar (3.3 and 4.5 days, respectively, p = 0.59). Four patients per group experienced postoperative complications. There were no deaths in the standard group but 1 patient (6%) in the hand assisted group died postoperatively. Mean time to partial and complete convalescence in the standard and hand assisted groups was 2.4 and 5.2, and 3.5 and 8.0 weeks, while mean followup was 27.4 and 9.6 months, respectively. CONCLUSIONS: Compared with standard laparoscopy hand assisted laparoscopy decreases operative time without significantly altering short-term parameters of convalescence. However, long-term convalescence after hand assisted laparoscopic radical nephroureterectomy is 1 to 3 weeks longer (p = 0.27). Longer followup in the hand assisted cohort is necessary to determine whether there are any differences in the 2 methods in regard to cancer control.

Aged↗

Current trends in urologic laparoscopic surgery.

PURPOSE: We examined the status of laparoscopy in urology and the impact of residency and fellowship training on the performance of laparoscopy as primary surgeon. We also examined whether performing nonsurgical tasks requiring two-handed dexterity had any link to the adoption of laparoscopic techniques by urologists. MATERIALS AND METHODS: A total of 8760 laparoscopy questionnaires containing 135 queries were mailed to urologists listed on the American Urological Association practicing urologists mailing list. The questions sought information on area of practice, time in practice, fellowship training, ambidexterity, laparoscopic experience, and experience with robotics. The response rate was 1.8% (155 of 8760). RESULTS: There appeared to be no significant correlation between the performance of laparoscopic surgery and participation in activities requiring bimanual dexterity. However, a correlation of strong statistical significance did exist between laparoscopic residency training and performance of laparoscopy after residency (p=0.003. There also was a correlation between fellowship training in laparoscopy/endourology and doing laparoscopy as primary surgeon. CONCLUSIONS: Participation in laparoscopic surgery during residency training is a major determining factor in performance of laparoscopy as a primary surgeon in practice. Younger surgeons trained in laparoscopy during residency are performing more laparoscopy post residency than those without laparoscopic training during residency. At present, there is a need to train more urologists in laparoscopy at the postgraduate level.

Adult↗

Tubeless percutaneous nephrolithotomy using hemostatic gelatin matrix.

We describe using hemostatic gelatin matrix (FloSeal; Baxter Inc., Irvine, CA) to provide hemostasis of the tract after percutaneous nephrolithotomy, thereby obviating a nephrostomy tube. For patients who are rendered stone free, a 7F, 11.5-mm occlusion balloon catheter, passed retrograde, is used to occlude the collecting system at the level of entry of the 30F Amplatz sheath. FloSeal is then injected through the partially retracted Amplatz sheath while withdrawing the applicator and the sheath in tandem. The guidewire is withdrawn per urethra until its tip resides in the renal pelvis. A 36-cm, 7F tail stent is passed retrograde, and the skin is closed with cyanoacrylate adhesive (Ethicon, Somerville, NJ). A Foley catheter is placed, to be removed the next morning; the patient can be discharged on postoperative day 1. The ureteral stent is removed in 5 to 7 days as an outpatient procedure.

Balloon Occlusion↗

Ureteral pseudodiverticulum associated with absorbable suture clips after laparoscopic pyeloplasty: case report.

A 48 year-old woman with pyelonephritis was found to have bilateral ureteropelvic junction (UPJ) obstruction and a nonfunctioning right kidney. She initially underwent a laparoscopic left nondismembered pyeloplasty using absorbable polydioxanone Lapra-Ty suture clips (Ethicon Endosurgery, Cincinnati, OH) to secure the anastomosis. An antegrade endopyelotomy was later necessitated. Both procedures were complicated by postoperative bacteruria and funguria. She then underwent a laparoscopic dismembered pyeloplasty, again utilizing Lapra-Ty suture clips to secure the anastomosis. Postoperatively, her course was complicated by anastomotic extravasation, bacteriuria, and funguria. Subsequently, an antegrade nephrostogram revealed a 2.5-cm diverticulum just distal to the UPJ, which contained numerous 2- to 4-mm filling defects. Nephroscopic exploration of the pseudodiverticulum revealed numerous Lapra-Ty clips, which were basket extracted. The pseudodiverticulum was fulgurated with a holmium laser. She eventually had restricturing with recurrence of the pseudodiverticulum and was treated successfully by open ureterocalicostomy.

Anastomosis, Surgical↗

Determination of cell viability after laparoscopic tissue stapling in a porcine model.

BACKGROUND AND PURPOSE: Surgical stapling devices are often used to secure the distal ureter along with a cuff of bladder during laparoscopic nephroureterectomy. As the viability of cells within the stapled tissue would be important in patients with upper urinary-tract transitional-cell carcinoma, we determined the viability of cells within the lines of various commercially available staplers in a porcine model. MATERIALS AND METHODS: Four laparoscopic stapling devices were used: two vascular and two tissue designs (US Surgical, Norwalk, CT, and Ethicon, Cincinnati, OH). The devices were deployed across a portion of the bladder, much as they would be during a nephroureterectomy to create a bladder cuff while excising the distal ureter. The animals were sacrificed 6 weeks later, and the stapled sites were harvested for histopathologic examination by an experienced genitourinary pathologist (PH). RESULTS: Grossly, there were no visible staples at harvest of the stapled bladder and the ureterovesical junction, with a completely healed bladder being seen in all four animals. On histologic examination with hematoxylin and eosin staining, there were distinctly viable cells within the staple lines of the ureterovesical junction and the bladder wall, similar to the unstapled control tissue. There were viable cells in all samples of tissues stapled by either vascular or tissue staplers. CONCLUSIONS: Deployment of both vascular and tissue staplers resulted in viable cells within the staple lines at the ureterovesical junction and bladder wall in this porcine model. There is a potential risk of tumor recurrence at the stapled site in patients who have the ureter and bladder cuff secured with these devices during laparoscopic nephroureterectomy for upper-tract transitional-cell carcinoma. Despite this concern, to date, over a period of 13 years, clinical experience has not revealed a single case of tumor recurrence within the stapled cuff of bladder. Careful endoscopic evaluation of the stapled bladder-cuff site after laparoscopic nephroureterectomy should minimize the potential for local tumor recurrence.

Animals↗