PubMed Health⌕ Search

Biomedical subjects

M S Pearle

Publications and source records attributed to M S Pearle.

At least 19 recordsLinked to original sources
PubMed1998

Safety and efficacy of the Alexandrite laser for the treatment of renal and ureteral calculi.

OBJECTIVES: To assess the safety and efficacy of the Alexandrite laser for intracorporeal lithotripsy of renal and ureteral stones in conjunction with ureterorenoscopy or percutaneous nephrostolithotomy. METHODS: We retrospectively analyzed the records of 137 patients with 169 calculi in 143 renoureteral units who were treated with the Alexandrite laser via a retrograde (91.5%) or antegrade (8.5%) endoscopic approach. RESULTS: Adequate intraoperative fragmentation of the stone was observed in 88.8% of the cases. No intraoperative complications were attributable to the laser. At a mean follow-up of 34 days, the overall stone-free rate was 74.4%. The stone-free rate for ureteral stones (n = 115) was 80%, whereas the stone-free rate for renal stones (n = 22) was only 44%. In the best subgroup of ureteral stones (10 mm or less in the distal ureter), the stone-free rate was 97.4%. CONCLUSIONS: The Alexandrite laser is a safe modality for intracorporeal lithotripsy and is highly effective for ureteral stones less than 10 mm in size.

Adolescent↗
PubMed1998

Color vision deficits during laser lithotripsy using safety goggles for coumarin green or alexandrite but not with holmium:YAG laser safety goggles.

PURPOSE: Laser lithotripsy requires urologists to wear laser eye protection. Laser eye protection devices screen out specific light wavelengths and may distort color perception. This study tests whether urologists risk color confusion when wearing laser eye protection devices for laser lithotripsy. MATERIALS AND METHODS: Urologists were tested with the Farnsworth Dichotomous Test for Color Blindness (D-15) and the Farnsworth-Munsell 100-Hue Test (FM-100) without (control) and with laser eye protection devices for coumarin green, alexandrite and holmium:YAG lasers. Error scores were tabulated. The pattern of color deficits was characterized with confusion angles, confusion index (C-index), scatter index (S-index) and color axes. Laser eye protection devices were tested with spectrophotometry for spectral transmittance and optical density. RESULTS: The D-15 transposition errors (mean plus or minus standard deviation) for control, holmium:YAG, alexandrite and coumarin green laser eye protection were 0 +/- 0, 0 +/- 0, 0.3 +/- 0.5 and 6.4 +/- 1.6, respectively (p = 0.0000001). The FM-100 error scores (mean plus or minus standard deviation) were 20 +/- 15, 20 +/- 14, 91 +/- 32 and 319 +/- 69, respectively (p = 0.0001). The confusion index scores indicated a mild color confusion for the alexandrite and pronounced color confusion for the coumarin green laser eye protection. The confusion angles and scatter indexes mimicked a congenital blue-yellow deficit for coumarin green laser eye protection. Color axes showed no significant deficits for control or holmium:YAG laser eye protection in any subject, red-green axis deficits in 3 of 6 tested with alexandrite and blue-yellow axis deficits in 12 of 12 tested with coumarin green (p < 0.001). Spectrophotometry showed that laser eye protection for coumarin green blocks light less than 550 nm., alexandrite blocks light greater than 650 nm. and holmium:YAG blocks light greater than 825 nm. CONCLUSIONS: Laser eye protection for coumarin green causes pronounced blue-yellow color confusion, whereas alexandrite causes mild red-green color confusion among urologists, holmium:YAG causes no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

Adult↗
PubMed1997

Laparoscopic creation of a catheterizable cutaneous ureterovesicostomy.

Nephrectomy and creation of a cutaneous ureterovesicostomy for intermittent catheterization of the bladder traditionally requires two surgical procedures performed through separate incisions. Herein we report completion of these procedures using a transperitoneal laparoscopic approach, with the ureterovesicostomy stoma created at one of the laparoscopic working ports. The clinical course was remarkable for a shortened postoperative hospitalization (48 hours) with minimal incisional pain, and an excellent long-term result with complete bladder emptying and resolution of urinary infections. Laparoscopic application of the Mitrofanoff principle for creation of a catheterizable cutaneous ureterovesicostomy combines the advantages of both, allowing optimal preservation of ureteral vascularity, minimal morbidity, and efficient bladder evacuation.

Adolescent↗
PubMed1997

Antimicrobial prophylaxis prior to shock wave lithotripsy in patients with sterile urine before treatment: a meta-analysis and cost-effectiveness analysis.

OBJECTIVES: To determine the efficacy and cost-effectiveness of routine antimicrobial prophylaxis prior to shock wave lithotripsy (SWL) in patients with a sterile pretreatment urine culture. METHODS: A structured MedLine search revealed eight prospective, randomized, controlled trials (RCTs) of active treatment versus placebo or no treatment (n = 885) and six clinical series (non-RCTs; n = 597) addressing the use of antimicrobial prophylaxis for SWL. A meta-analysis was performed on the eight RCTs, with the primary outcome being the diagnosis of a urinary tract infection (UTI) post-SWL. A cost analysis was performed comparing a prophylactic strategy (prophylaxis for every patient and treatment for post-SWL UTIs) with a treatment-only strategy for post-SWL UTIs using various antimicrobial combinations and the median probability of post-SWL UTIs determined by meta-analysis. RESULTS: The incidence of post-SWL UTIs ranged from 0% to 28% in the control group and from 0% to 7.7% in the patients who underwent prophylaxis. Combining the placebo/no-drug treatment arms in the six RCTs by meta-analysis (Bayesian analysis) resulted in a median probability of a post-SWL UTI of 5.7% (95% confidence interval [CI] 3.8% to 8.4%). For the drug treatment arms, the median probability of a UTI was 2.1% (95% CI 0.9% to 3.6%). Relative risk (RR) analysis resulted in an overall RR of post-SWL UTIs with prophylaxis versus without prophylaxis of 0.45 (95% CI 0.22 to 0.93) (P = 0.0005). Depending on the antimicrobial regimen used for prophylaxis and treatment, a prophylactic strategy added minimally to the overall treatment cost of SWL, and proved cost beneficial when taking into consideration serious UTIs requiring inpatient treatment. CONCLUSIONS: A policy of antibiotic prophylaxis prior to SWL in patients with sterile pretreatment urine cultures is efficacious in reducing the rate of post-SWL UTIs. Discounting inpatient episodes for sepsis and acute pyelonephritis, however, the strategy is not cost-effective. In contrast, using literature-derived incidence estimates for post-SWL urosepsis or pyelonephritis necessitating inpatient treatment, prophylaxis becomes both efficacious and cost-effective, and thus constitutes a dominant strategy.

Antibiotic Prophylaxis↗
PubMed1997

Medical therapy, calcium oxalate urolithiasis.

The development of diagnostic protocols that identify specific risk factors for calcium oxalate nephrolithiasis has led to the formulation of directed medical regimens that are aimed at correcting the underlying metabolic disturbances. Initiation of these treatment programs has reduced markedly the rate of stone formation in the majority of patients who form stones. This article discusses the rationale that underlies the choice of medical therapy for the various pathophysiologic causes of calcium oxalate nephrolithiasis and the appropriate use of available medications.

Calcium↗
PubMed1997

Bolus injection v drip infusion contrast administration for ureteral stone targeting during shockwave lithotripsy.

Intraoperative excretory urography may be used to facilitate stone targeting during in situ SWL for ureteral stones, precluding the need for ureteral catheter placement. We compared bolus injection with drip infusion urography for efficacy in stone localization. Twenty-seven patients with normal renal function and a solitary, difficult to visualize, radiopaque ureteral calculus were randomized to receive intravenous contrast by either bolus injection (N = 13) or drip infusion (N = 14). The bolus injection patients received an average of 74 mL of Conray 400 contrast over 1 minute; the drip infusion patients received an average of 92 mL of contrast over 15 minutes. After bolus injection, it took an average of 12 minutes to opacify the ureter compared with 14 minutes after drip infusion (P = 0.62). It took longer to initiate (5 minutes) and complete (6 minutes) treatment after drip infusion than after bolus injection (P = 0.28 and P = 0.16, respectively). Imaging time was significantly longer in the infusion group than in the bolus group (12 v 7 minutes; P = 0.04). Stone-free rates were similar in the two groups: 100% for the bolus group and 91% for the infusion group. No patient in either group experienced an adverse reaction to the contrast. Overall, the two methods of contrast administration were equally efficacious for stone targeting during SWL. However, bolus injection required lesser amounts of contrast, provided more rapid opacification of the ureter, and resulted in an overall shorter procedural time, although the only statistically significant differences were in imaging time and contrast volume.

Contrast Media↗
PubMed1997

Laparoscopic pneumodissection: results in initial 20 patients.

BACKGROUND: The efficiency of laparoscopic procedures has been hindered by a lack of instrumentation for blunt tissue dissection. We evaluated here the efficacy of a new 5-mm laparoscopic dissecting instrument, a pneumodissector. This instrument allows the surgeon to use short bursts of high-pressure carbon dioxide to bluntly dissect fatty tissue. STUDY DESIGN: In 20 patients undergoing a variety of laparoscopic procedures, a 5-mm laparoscopic pneumodissector was used. Subjective assessment of the efficacy of the instrument was recorded. In addition, acid-base changes were measured by blood gas determination, and serum chemistries were obtained before, during, and after the procedure. RESULTS: The pneumodissector enhanced dissection of the kidney, ureter, and major blood vessels and shortened the operative time for laparoscopic nephrectomy. Although statistically significant changes in acidbase values occurred with use of the pneumodissector, these changes were not clinically significant and were no different than what is normally seen during carbon dioxide pneumoperitoneum. CONCLUSIONS: Laparoscopic pneumodissection is a safe and efficacious technique for rapid blunt tissue dissection.

Acid-Base Equilibrium↗
PubMed1996

Acucise endopyelotomy: assessment of long-term durability.

PURPOSE: We evaluated the long-term efficacy of Acucise endopyelotomy. MATERIALS AND METHODS: A total of 28 patients with 28 ureteropelvic junction obstructions was reevaluated 2 or more years after Acucise endopyelotomy (mean 32.5 months). Subjective analysis was done with analog pain scales and objective analysis was performed with diuretic renal scintigraphy. RESULTS: Subjective followup was available for all 28 patients, and 17 (61%) had a favorable response with 36% totally free of pain and 25% markedly improved. Among 26 patients with objective followup (93%) 21 (81%) had a patient ureteropelvic junction based on a diuretic renal scan with a half-time of less than 10 minutes or a normal Whitaker test. Among all regularly followed patients failure occurred uniformly within 1 year. CONCLUSIONS: Acucise endopyelotomy is an effective and durable method for treating ureteropelvic junction obstruction.

Adolescent↗
PubMed1996

Acucise endopyelotomy: evolution of a less-invasive technology.

Since its introduction in 1993, the electrosurgical cutting balloon device (Acucise) has been utilized for endopyelotomies by a number of investigators. The fact that the procedure can be performed in a completely retrograde fashion under fluoroscopic guidance without percutaneous access has made Acucise endopyelotomy appealing to many urologists. To date, overall Acucise endopyelotomy success rates ranging from 66% to 84% have been reported. The average hospital stay has ranged from 1.7 to 3.7 days, and serious complications have been rare (transfusion 0-2%, bleeding necessitating embolization 0-3%). On the basis of its track record and its minimally invasive nature, a compelling argument can be made for use of the Acucise device whenever an endopyelotomy is indicated.

Catheterization↗
PubMed1996

Use of ureteral stents after endopyelotomy.

Despite the widespread practice of endopyelotomy for the management of ureteropelvic junction obstruction, the optimal conditions for ureteral healing after endoincision remain largely untested. Current recommendations for the use of large-caliber graduated endopyelotomy stents and a 6-week duration of stenting are being challenged by recent reports of successful outcomes with the use of standard, small-caliber ureteral stents and early stent removal. Moreover, improvements in stent design have led to the development of endopyelotomy stents with improved biocompatibility, enhanced case of insertion, and fewer adverse effects.

Child↗
PubMed1996

Endourologic management of stone-bearing excluded calices: contrasting case reports.

Calculi in a noncommunicating or excluded calix may be associated with infection, pain, and focal renal damage. Some authors have recommended removal of these calculi and reestablishment of the pelvicaliceal communication, either by dilation of the infundibulum or creation of a neoinfundibulum, in order to prevent recurrent stone formation and infection. Herein, we report two patients with stones in a completely excluded calix, one after repeated courses of shockwave lithotripsy for a staghorn calculus and the other after recurrent pyelonephritis. The combined approach is especially helpful if the examiner is in doubt about the anatomy (true calix v caliceal diverticulum) or if a natural infundibulum cannot be identified by antegrade endoscopy.

Adult↗
PubMed1996

Laparoscopic bladder seromyotomy: laboratory experience.

Twelve female microminipigs with normal bladder capacity underwent laparoscopic bladder seromyotomy. Three other female microminipigs were added to the study as controls. Urodynamic studies and cystograms were performed preoperatively and at 2 and 4 months after a laparoscopic bladder seromyotomy. Histologic studies of the treated bladders were performed when the animals were euthanized at 4 months. The operation was completed in all 12 test animals. There was no significant difference in bladder capacity or leak-point pressure between the 12 seromyotomy and the 3 control bladders at any time point. Histologically, over the seromyotomy site, the urothelium remained intact; however, the muscularis was attenuated, and a thin layer of fibrotic tissue replaced the normal serosal covering of the bladder. Laparoscopic bladder seromyotomy can be performed reliably in the porcine animal model. Not surprisingly, no significant changes in bladder capacity or bladder compliance were seen in our study of normal bladders. An animal model of a neuropathic contracted bladder is needed to assess more accurately the physiological impact of laparoscopic seromyotomy.

Animals↗
PubMed1996

Comparison of acucise endopyelotomy and endoballoon rupture for management of secondary proximal ureteral stricture in the porcine model.

At this point in time, endopyelotomy is first-line therapy for both primary and secondary adult ureteropelvic junction obstruction (UPJO) in many medical centers. However, the potential, albeit small, for significant bleeding with any endoincision of the UPJ has sparked interest in the simple, less morbid technique of endoballoon rupture. To date, no comparative data are available on the effectiveness of these two techniques. Thirty female minipigs were randomized to cutting balloon (Acucise) endopyelotomy (AEP) (N = 13), endoballoon rupture (EBR) (N = 13), or a control arm (N = 4). Following baseline retrograde pyelogram (RPG) and diuretic renogram (DRG), a secondary proximal ureteral stricture was created by laparoscopic ligation of the UPJ. After 8 weeks, AEP or EBR was performed in each of the study pigs. In 16 pigs (8 AEP, 8 EBR), a 7F 22-cm ureteral stent was placed (chronic arm). After 6 weeks, the stent was removed, and a second RPG and DRG were performed. Three months post-treatment, after RPG and DRG, the renal units were harvested, and histologic sections of the affected UPJ, contralateral normal ureter, and ipsilateral kidney were examined. Ten pigs (5 AEP, 5 EBR) underwent harvest immediately after treatment (acute arm). The four control animals remained untreated. At 8 weeks, all minipigs had obstructive findings on RPG and DRG. All UPJs could be treated but one, which had an impassable stricture; there were no perioperative complications. In the acute arm, all UPJs were patent. All five AEP ureters had evidence of an uneven cut and cautery effect. Of the EBR ureters, two had smooth tears and three had ragged tears, and none had evidence of cautery effect. In the chronic arm, 3 months after either AEP or EBR, all minipigs had a patent UPJ, yet only 5 of 16 had an improved 1 1/2 by DRG. Histologic sections of the affected UPJs from 20 minipigs in the chronic arm (8 AEP, 8 EBR, 4 controls) were indistinguishable among the three groups; each revealed significant periureteral fibrosis and chronic inflammation with a mainly unremarkable muscular layer. However, histologic sections of 25 treated kidneys, including both acute and chronic animals (13 AEP, 12 EBR), revealed endstage renal disease (N = 10), chronic inflammatory changes (N = 7), or normal tissue (N = 8). Again, there was no trend favoring either AEP and EBR. In summary, in this laboratory study, we could detect no difference in outcome between an incisional endopyelotomy and an endoballoon rupture for treating secondary UPJO.

Animals↗
PubMed1996

The unintubated ureterotomy endourologically revisited.

PURPOSE: The duration of stenting after endoureterotomy is a controversial issue. An even more basic question, however, is whether stent placement is needed at all. We performed a porcine study to address this question. METHODS: A unilateral midureteral stricture was created in 20 minipigs. Six weeks later, 15 pigs underwent endoureterotomy. In 10 animals, a 7F ureteral stent was placed for 1 week. Five pigs remained unstented. Three months later, all 20 ureters were studied radiographically and were harvested. RESULTS: Three of 5 control animals and 2 of 10 stented animals has strictures. In the unstented study group, all 5 animals had a nonobstructing dilation at the site of endoureterotomy. This was corroborated by a normal furosemide washout renal scan in all 3 animals so tested. CONCLUSIONS: The result of unstented endoureterotomy in the porcine model suggests that, after endoureterotomy of secondary midureteral strictures, stenting may be unnecessary.

Animals↗
PubMed1995

Laparoscopic pneumodissection: initial clinical experience.

OBJECTIVES: We evaluated the efficacy of a new laparoscopic dissecting instrument that fires intermittent bursts of high-pressure carbon dioxide to separate tissue along natural planes. METHODS: The pneumodissector (PD) was used in 2 patients undergoing laparoscopic procedures. Serum creatinine and bicarbonate were measured before and after the procedure, and arterial blood gases were measured before, during, and after use of the PD. Subjective assessment of the ease of dissection with the PD by the first assistant was recorded. RESULTS: Acidosis and hypercarbia were not observed with use of the PD. The PD facilitated dissection along the iliac vessels, around the kidney, and in the renal hilum. CONCLUSIONS: The PD is a feasible method for rapid, blunt dissection during laparoscopic procedures.

Adolescent↗
PubMed1995

Extracorporeal shock-wave lithotripsy of middle ureteral stones: are ureteral stents necessary?

OBJECTIVES: To ascertain whether insertion of a ureteral stent improves the outcome of middle ureteral (overlying the pelvic bone) stones treated with extracorporeal shock-wave lithotripsy (ESWL). METHODS: Thirty-three patients with middle ureteral stones were treated with ESWL at our institution between October 1991 and October 1994. Twenty-six patients were available for follow-up; 14 patients were treated with stent bypass, 8 were treated in situ, and 4 patients were treated after percutaneous nephrostomy (PCN). All patients were treated initially on an unmodified Dornier HM-3, and all but 4 patients were treated in the prone position on a modified Stryker frame. Follow-up consisted of a plain abdominal radiograph, intravenous urogram, occasionally a retrograde urogram, and a telephone interview. RESULTS: The overall stone-free rate for ESWL alone was 73%, and the efficiency quotient was 69. The stone-free rates after a single treatment for the stent bypass, in situ, and PCN groups were 71%, 63%, and 75%, respectively. Overall, 4% of patients required retreatment, 19% of patients required an auxiliary procedure, and 8% of the patients required hospital or emergency room admissions for renal colic. For stones 10 mm or greater (9), stone-free rates after one treatment for the stent bypass, in situ, and PCN groups were 33%, 33%, and 67%, respectively; for stones less than 10 mm (17), success rates were 82%, 80%, and 100%, respectively. CONCLUSIONS: Pretreatment stinting provides no advantage over in situ ESWL for middle ureteral calculi (Fisher's exact test, P = 1.0). ESWL is a reasonable initial therapy for middle ureteral stones less than 10 mm.

Adult↗