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Biomedical subjects

A J Kirsch

Publications and source records attributed to A J Kirsch.

At least 19 recordsLinked to original sources
PubMed1997

Economic evaluation of famciclovir in reducing the duration of postherpetic neuralgia.

The economic impact of famciclovir therapy for postherpetic neuralgia (PHN) in patients with acute herpes zoster was studied. A decision-analytic model of the treatment of herpes zoster and PHN was used to compare the cost of PHN between patients treated with oral famciclovir 500 mg three times daily for seven days and patients not receiving any antiviral therapy. The effects of famciclovir on PHN in the model were based on the results of a randomized, double-blind trial in 419 adult outpatients. The cost of the course of famciclovir therapy (21 tablets) was estimated as the sum of the drug's wholesale acquisition cost and the pharmacy dispensing cost. The cost of treating PHN (physician visits, medications, and miscellaneous nondrug therapy) was estimated by consulting a panel of physicians. According to the model, the cost of treating PHN was $85 lower per famciclovir recipient ($294 for famciclovir versus $379 for no antiviral therapy). The net cost of famciclovir therapy was $23 per patient ($108 for acquisition and dispensing minus the $85 savings). Among patients 50 years of age or older, famciclovir reduced the average cost of PHN by $155 ($414 for famciclovir versus $569 for no antiviral therapy) and yielded a net savings of $7 per patient. A model for the use of famciclovir to treat acute herpes zoster showed that the cost of such therapy was largely offset by savings in the cost of treating this complication.

2-Aminopurine↗
PubMed1997

Results of laser tissue soldering in vasovasostomy and epididymovasostomy: experience in the rat animal model.

UNLABELLED: The use of microsurgical techniques (vasovasostomy and epididymovasostomy) for vasectomy reversal has now enabled surgeons to perform both procedures with certainly acceptable success rates. However, these operations are technically demanding and require special training in microsurgery. PURPOSE: A new method of performing these procedures using laser tissue soldering is described and results are evaluated. Laser tissue soldering is different from laser welding in that it involves the laser activation of a protein solder with a dye specific for the specific wavelength of laser light; therefore, surrounding tissue is not affected by the laser. MATERIALS AND METHODS: Ten rats underwent bilateral vasovasostomy and eleven underwent bilateral epididymovasostomy. In each rat, a sutured anastomosis was performed on one side while laser tissue soldering was performed on the other. Animals were sacrificed after one month and anastomoses were evaluated for patency and presence of sperm granulomas. Histologic analysis was also performed. RESULTS: Patency rates were 8/10 (80%) for sutured vasovasostomy versus 9/10 (90%) for the laser technique. Epididymovasostomy patency rates were 8/11 (73%) for sutured versus 9/11 (82%) for the laser technique. Mean operative times were significantly shorter for lasered anastomoses when compared to controls. The frequency of granuloma formation did not significantly differ between laser and control groups. CONCLUSIONS: Laser tissue soldering resulted in similar patency when compared to a conventional 2 layered sutured anastomosis while decreasing operative time. In addition, since fewer sutures are placed, the laser method is less technically demanding.

Animals↗
PubMed1996

Effects of diode laser welding with dye-enhanced glue on tensile strength of sutures commonly used in urology.

BACKGROUND AND OBJECTIVE: Tissue welding using laser-activated protein solders may soon become an alternative to sutured tissue approximation. In most cases, approximating sutures are used both to align tissue edges and provide added tensile strength. Collateral thermal injury, however, may cause disruption of tissue alignment and weaken the tensile strength of sutures. The objective of this study was to evaluate the effect of laser welding on the tensile strength of suture materials used in urologic surgery. STUDY DESIGN/MATERIAL AND METHODS: Eleven types of sutures were exposed to diode laser energy (power density = 15.9 W/cm2) for 10, 30, and 60 seconds. Each suture was compared with and without the addition of dye-enhanced albumin-based solder. After exposure, each suture material was strained (2"/min) until ultimate breakage on a tensometer and compared to untreated sutures using ANOVA. RESULTS: The strength of undyed sutures were not significantly affected; however, violet and green-dyed sutures were in general weakened by laser exposure in the presence of dye-enhanced glue. Laser activation of the smallest caliber, dyed sutures (7-0) in the presence of glue caused the most significant loss of tensile strength of all sutures tested. CONCLUSION: These results indicate that the thermal effects of laser welding using our technique decrease the tensile strength of dyed sutures. A thermally resistant suture material (undyed or clear) may prevent disruption of wounds closed by laser welding techniques.

Adhesives↗
PubMed1996

Laser welding with albumin-based solder: experimental full-tubed skin graft urethroplasty.

BACKGROUND AND OBJECTIVES: Fistula and stricture formation at the site of sutured anastomoses are frequent complications of major urethroplasty. We performed urethroplasty using laser-welded skin tube grafts in the hope that in addition to being free of suture holes, grafts would be as strong as or stronger than sutured controls. STUDY DESIGN/MATERIAL AND METHODS: Scrotal skin was harvested from each of 11 rabbits and fashioned into tubes 3-4 cm in length using either conventional suture techniques or laser welding. Welding was performed using an 808-nm diode laser and a dye-enhanced solder composed of albumin and sodium hyaluronate. Laser power density was 15.9 watts/cm2. For each graft, leak pressure, and urethroplasty time (tube creation and anastomosis to native urethra) were measured. RESULTS: Urethroplasty time was significantly shorter and initial leak pressures were seven times greater in the laser-welded group. CONCLUSIONS: The near-uniform occurrence of strictures in both groups suggests that the rabbit is not an ideal model for free tube graft urethroplasty. However, our data indicate that laser welding with albumin-based solder, when used in the appropriate setting, may offer the potential for the rapid creation of watertight grafts in reconstructive urology.

Aluminum↗
PubMed1996

Absorbable stapling techniques in continent urinary diversion.

The principle of bowel detubularization to decrease peristaltic pressure and increase reservoir capacity is applied in contemporary continent urinary diversions. The process of detubularization and refashioning of the spatulated bowel segment approximates 1 of operating time and is the most time-consuming aspect of pouch construction. The employment of devices applying absorbable staples ("absorbable staplers") has substantially reduced the time required to fashion bowel reservoirs. This article reviews the adaptation of the absorbable stapler to continent urinary diversion using small- and large-bowel segments.

Colon↗
PubMed1996

Giant multilocular cystadenoma of the prostate.

Giant multilocular prostatic cystadenoma is a rare clinicopathologic entity characterized by benign histology and the ability to enlarge massively. The lesion may arise from the prostate gland either in continuity with the prostatic urethra or separate from it, or it may arise as a lesion distinct from the prostate gland. Obstructive voiding symptoms occur in all reported cases. The use of preoperative radiographic evaluation, such as magnetic resonance imaging, effectively defines the lesion's benign nature and aids in planning surgical extirpation.

Aged↗
PubMed1996

Hypospadias repair by laser tissue soldering: intraoperative results and follow-up in 30 children.

OBJECTIVES: We examined the use of laser tissue soldering (LTS) as an adjunct to suturing of, as well as a primary means of, tissue closure in urethral reconstruction. METHODS: Since June 1994, 26 boys ranging in age from 3 months to 14 years (mean 3.0 years) underwent hypospadias repair using LTS techniques. The classification of hypospadias was subcoronal in 13, midpenile in 5, penoscrotal in 7, and scrotal in 1. Laser tissue soldering was used in an additional 4 patients: tunica vaginalis patch graft corporoplasty in 2 (scrotal hypospadias), epispadias fistulae in 1, and urethral diverticulum in 1. Of these cases, 3 hypospadias repairs were completely sutureless. An intraoperative comparision was made between suturing and LTS with respect to operative time and degree of difficulty in performing LTS. Postoperatively, patients were examined to determine complications, including stricture, fistula, or impaired wound healing. An unselected group of 25 consecutive boys undergoing hypospadias repair between 1991 and 1992 served as a historical control group. RESULTS: No intraoperative complications resulted from laser activation. In 5 of the 30 procedures (16.6%), suture disruption was noted to occur, with a higher incidence seen with finer, dyed suture material. For hypospadias repair, the average time to suture was 6.7 min/cm (n = 23), whereas it was 3.1 min/cm for adjunctive LTS (n = 23) and 1.4 min/cm for sutureless urethroplasty (n = 3). Follow-up ranged from 3 to 22 months (average 9.6). Four fistulae were noted (1 onlay, 2 skin tube grafts, 1 Thiersch tube) each following penoscrotal or scrotal hypospadias repair; a fifth fistula developed following a traumatic catheterization in a sutureless repair. The overall complication rate in the LTS group was 19% (5 of 26) versus 24% (6 of 25) for controls, whereas that for the distal forms of hypospadias was 11% (2 of 18) and 13.6% (3 of 22), respectively. CONCLUSIONS: Tissue soldering with laser and chromophore-doped solder is feasible, safe, and easy to perform. Laser tissue soldering may be an alternative to standard microsuture technique for hypospadias repair.

Adolescent↗
PubMed1996

Dural closure with laser tissue welding.

This study investigates the use of tissue-soldering techniques to substitute or reinforce traditional suture closure of dural incisions. Fresh human cadaveric dura was incised and subsequently closed by use of three techniques: (1) conventional interrupted suture with 4-0 silk (n = 25), (2) laser solder reinforced suture closure (n = 25), and (3) laser solder closure alone (n = 25). Anastomosis tensile strength and hydrostatic leak pressures were measured. Dural repair was also performed in 15 live Lewis rats. Dural closure was accomplished with 9-0 Prolene sutures (n = 5), laser-reinforced suture closure (n = 5), and laser solder closure alone (n = 5). Histologic examination of the closure immediately after soldering and 2 weeks later was performed. Suture closure alone had the lowest leak pressure, 9.4 +/- 1.7 mm Hg, and an intermediate break point, 13.3 +/- 2.1 Kgf/cm2. Measurements with laser solder alone revealed a mean leak pressure of 26.2 +/- 3.7 mm Hg and a break point of 4.6 +/- 1.4 Kgf/cm2. Solder-reinforced suture closure leak pressure measured 64.0 +/- 6.7 mm Hg and 21.4 +/- 2.4 Kgf/cm2. There was a statistically significant increase in leak pressure and tensile strength in the closures performed with laser weld reinforcement of traditional suture technique (p = 0.0001). Dural closure with laser tissue welding alone provided an immediate leak-free closure, but with poor tensile strength. Histologic examination of welded dura and underlying brain tissue showed no evidence of thermal injury in four of five animals studied. Laser welding may significantly decrease the incidence of cerebrospinal fluid leak after dural closure. In addition, laser tissue welding also makes dural closure possible where space constraints make traditional suture closure difficult.

Animals↗
PubMed1996

Pediatric continent reservoirs and colocystoplasty created with absorbable staples.

PURPOSE: For patients undergoing continent urinary diversion or bladder augmentation the process of detubularization and refashioning bowel into a spherical configuration is often tedious and time-consuming, and may cause undesirable blood loss. We sought to determine whether using absorbable staples in a pediatric population was safe, effective and economical. MATERIALS AND METHODS: We performed our technique of rapid right colon pouch construction in 18 children (average age 12.3 years) undergoing continent urinary diversion (8) or colocystoplasty (10). We evaluated the cost of performing the procedure relative to conventional suturing as well as the results of up to 3 years of followup. RESULTS: In all cases pouch construction using absorbable staples was performed easily and rapidly, and resulted in minimal blood loss. Using the staples decreased operative time by approximately 1 hour and saved nearly $350 per case. Only 1 significant complication requiring surgical intervention developed during extended followup (delayed pouch rupture) and in that case the use of absorbable staples did not contribute to morbidity. None of the patients had reservoir stones. CONCLUSIONS: The use of devices applying absorbable staples in conjunction with a 1-step method of colonic reservoir construction proves to be effective and economically sound for continent urinary diversion and bladder augmentation.

Absorption↗
PubMed1995

Laser tissue soldering in urinary tract reconstruction: first human experience.

OBJECTIVES: Laser tissue soldering (LTS) in the urinary tract provides an immediate leak-free seal and may avoid complications seen with conventional repair (such as fistula and stricture). We have begun a Phase I clinical trial investigating the use of LTS in performing urologic reconstructive surgery. METHODS: Ten patients (aged 3 months to 38 years) underwent urologic reconstruction using LTS with a protein solder composed of human albumin (42%) and indocyanine green dye. In each case standard microsuture repair preceded laser-soldered suture line reinforcement. Anastomotic closure time and immediate leak pressure were measured. Postoperatively, all patients were evaluated for evidence of complications, including stricture, fistula formation, or impaired healing. RESULTS: Using LTS as an adjunct to suturing added an average of 7.9 +/- 3.0 minutes (28%) to the overall mean anastomotic time of 28.3 +/- 9.4 minutes. Intraoperative leak pressure measurements for laser-soldered anastomoses (> or = 94.2 +/- 24.2 mm Hg) were significantly higher (P < 0.001) than primarily sutured anastomoses (20 +/- 2.9 mm Hg). Two instances of suture disruption (20%) occurred during laser activation, neither of which were repaired with sutures. Average follow-up for all patients was 7.1 + - 2.2 months. There were no intraoperative or postoperative complications, including the 2 patients with suture disruption. CONCLUSIONS: These initial clinical results indicate that LTS is safe, easy to perform, and, contrary to conventional suturing, provides an immediate leak-free closure. Follow-up in these and other patients, as well as those undergoing sutureless and stent-free procedures, will determine whether our method of LTS benefits patients undergoing urologic reconstruction.

Anastomosis, Surgical↗
PubMed1995

Testicular dysmorphism associated with abdominoscrotal hydroceles during infancy.

Abdominoscrotal hydrocele (ASH) in infancy is a rarely reported condition. We present an 11-week-old infant who was born with massive scrotal enlargement. At exploration, he was found to have large bilateral ASHs and bilateral fusiform testes. Gross morphologic testicular changes associated with hydrocele have previously only been reported in adults. Our patient is the youngest to be reported with ASHs.

Abdomen↗
PubMed1995

Testicular microlithiasis in a child with torsion of the appendix testis.

We report on an 8-year-old boy with a unilateral testicular mass and bilateral diffusely echogenic testes on sonography. At inguinal exploration torsion of an appendix testis with a reactive phlegmon was found and testis biopsy revealed significant testicular microlithiasis. To our knowledge our case demonstrates a previously undescribed presentation of testicular microlithiasis. The literature is reviewed and this disease entity is discussed.

Calculi↗
PubMed1995

Laser welding versus suturing in tunica vaginalis and venous patch graft corporoplasty.

Congenital penile curvature may result from corporeal disproportion in nearly 40% of cases, while in adults scarring of the corporeal bodies or periurethral fibrosis accounts for the majority of cases. Some surgeons advocate lengthening the fibrosed corporeal bodies by excising tunica albuginea and grafting such defects to straighten the penis. Tunica vaginalis, dermis, dorsal vein and lyophilized dura have been used for this purpose. Traditionally, these graft biomaterials have been sutured to the tunica albuginea. We assessed the feasibility, short-term safety and efficacy of diode laser tissue welding using albumin based solder and indocyanine green dye to perform patch graft corporoplasty in the dog. Ten animals were subjected to bilateral transverse excision of 1 x 2 cm. sections of tunica albuginea. Corporoplasty was performed using grafts composed of saphenous vein (5) or tunica vaginalis (5). Microsurgical repair with 7-zero polydioxanone suture (10) was compared to contralateral laser welded repair (10) by recording operative time, initial and short-term bursting pressures (mean plus or minus standard deviation) and histological analysis. Operative time on the laser side (9.8 +/- 2.3 minutes) was significantly shorter (p < 0.05) than on the suture side (17.1 +/- 5.1 minutes). Leak pressures, initially (laser 105.7 +/- 23.8 mm. Hg versus suture 35.3 +/- 8.0 mm. Hg), at 3 to 5 days (greater than 333.3 +/- 62.4 mm. Hg versus 136.6 +/- 39.4 mm. Hg) and at 7 to 10 days (greater than 397.8 +/- 39.8 mm. Hg versus 191.5 +/- 46.4 mm. Hg) were higher (p < 0.05) in the laser side compared to controls. Graft failure (necrosis) occurred in 3 repairs (2 laser on day 4 and 1 suture on day 10). Viable tissue with minimal differences in foreign body reaction between groups was observed in the remaining grafts. We conclude that laser welded patch graft corporoplasty using tunica vaginalis or vein is easy to perform, and provides excellent initial and short-term leak pressures. The use of laser welding in conjunction with suturing may be beneficial in corporoplasty for congenital or acquired penile curvature.

Animals↗
PubMed1995

Bladder neck closure in association with continent urinary diversion.

Bladder neck closure is not a standard part of continent urinary diversion. When bladder augmentation and continent urinary diversion are done simultaneously, it is frequently convenient and advantageous to leave the native bladder neck intact as long as there is a reasonable degree of intrinsic continence. Even in patients with marginal control the effect of lowering intravesical pressure and increasing intravesical volume will often produce acceptable continence. At times, particularly in patients who have undergone multiple surgical procedures involving the bladder neck, there is poor intrinsic resistance. To provide acceptable continence in these cases bladder neck closure is a necessary part of continent diversion. Between 1990 and 1993 we treated 6 male and 7 female patients, most of whom underwent simultaneous bladder augmentation and continent urinary diversion, and they had poor intrinsic outlet resistance. Patient age ranged from 8 to 22 years. Underlying diagnoses included thoracic myelomeningocele in 5 patients, bladder exstrophy in 5, bladder leiomyosarcoma in 1 and extensive pelvic trauma in 1 as well as 1 previously separated conjoined twin. Three patients had artificial urinary sphincter failure and 3 had failure of urethral sling procedures. A clean intermittent catheterization program had failed in 12 patients and all 13 had diurnal incontinence. Bladder neck and urethral resistance was evaluated using voiding cystourethrography and urodynamics to measure leak point pressure and bladder capacity. Reliable bladder neck closure is historically difficult to achieve and is best done at the time of diversion. We have had initial success in 12 of our 13 cases and subsequently in all 13 using a technique of bladder neck division, 2-layer closure and omental interposition between the bladder neck closure and urethra.

Adolescent↗
PubMed1995

Sutureless rabbit bladder mucosa patch graft urethroplasty using diode laser and solder.

Fistula and strictures at the site of sutured anastomoses are frequent complications of major urethroplasty. We harvested bladder mucosa in 26 rabbits to repair large defects in the proximal urethra using laser-activated solder in the hope that such a repair would be stronger, faster to create and avoid common complications seen with conventional repair. Large oval defects were created in the proximal urethra in all animals undergoing urethroplasty. Twelve animals underwent bladder mucosa graft closure via diode (808 nm.) laser activation of an albumin-based solder (50% were suture-free). Fourteen additional animals underwent closure with 7-zero polydiaxanone suture (controls). Leak pressure and time of repair were recorded for each graft. Additional sections of bladder mucosa were harvested, transected and repaired by laser welding to determine tensile strength. In both groups, radiography, urethroscopy and clinical course were evaluated for as much as 6 weeks postoperatively. Urethroplasty time was significantly (p < 0.01) shorter for the laser group (13.8 +/- 2.5 minutes) than for the sutured repair group (24.0 +/- 5.3 minutes). Initial leak pressures for the lasered grafts averaged at least 4 times those of sutured grafts (p < 0.01). The tensile strength for lasered bladder mucosa was 3.16 +/- 1.12 kg./cm.2 Early retrograde urethrograms (RUG) performed at 7 days (n = 5) revealed urinary extravasation and fistula formation in 2 control animals compared with a normal urethral appearance in 3 lasered repairs. Early retrograde urethrograms performed at 21 days (n = 21) demonstrated smooth-walled urethras with no evidence of fistula, stricture, or urinary extravasation in the lasered group; varying degrees of reactive mucosal proliferation were seen in the controls. Urethroscopy confirmed these observations. At 6 weeks, histologic examination confirmed the presence of viable graft in all animals. We conclude that bladder mucosa patch graft urethroplasty using diode laser welding and albumin-based solder is an attractive alternative to conventional methods.

Animals↗
PubMed1994

Rapid construction of right colon pouch: initial clinical experience.

Between December 1992 and July 1993, 7 patients who underwent urinary diversion after cystectomy or bladder augmentation had colon pouches constructed with an "absorbable" staple. Our "one-step" technique of colon pouch construction incorporates standard principles of bowel detubularization and refashioning using absorbable GIA staples. The technique is easily learned and decreases operative time and blood loss. Herein we report follow-up of the first 7 patients undergoing this modification.

Adolescent↗
PubMed1994

Renal effects of CO2 insufflation: oliguria and acute renal dysfunction in a rat pneumoperitoneum model.

OBJECTIVE: To determine the mechanism by which oliguria develops during raised intra-abdominal pressure secondary to CO2 insufflation, we created a rat pneumoperitoneum model. METHODS: Male Sprague-Dawley rats (n = 67) were organized into three groups. Each group was subjected to abdominal pressures of 0 (control), 5, or 10 mm Hg, over one, two, and four hours. Fourteen additional rats underwent a two-hour period of 10 mm Hg insufflation pressure followed by desufflation to 0 mm Hg. Urine output (UO) and serum creatinine levels were measured both during insufflation at one, two, and four hours, and two, four, ten, and twenty-two hours following its release. These measurements were compared to control values at each time point. Ultrasonic flow probes placed around both the inferior vena cava (IVC) and abdominal aorta during insufflation characterized the effects of increased abdominal pressure on blood flow. The flow rate was determined at insufflation pressures of 0 (control, 100% flow) to 25 mm Hg. RESULTS: Rats subjected to 10 mm Hg pressure had significant decreases in UO (oliguria) compared to controls for up to four hours (P < 0.01). There were no significant differences in UO in the control or 5 mm Hg groups over each time interval. While a reduction in UO was observed at two, four, and ten hours postrelease, significance was achieved only at ten hours (P < 0.006). By twenty-two hours postrelease, no differences in UO were observed. Serum creatinine elevations declined two hours postdesufflation. IVC flow was reduced by 92.9 percent at 10 mm Hg, while arterial flow decreased by 46.4 percent. Flow was restored to preinsufflation levels after release of pneumoperitoneum. CONCLUSIONS: Oliguria can be produced in rats undergoing pneumoperitoneum. The renal effects of pneumoperitoneum are most likely related to renal vascular insufficiency from central venous compression.

Acute Disease↗