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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
PubMed2001

Optimal solder and power density for diode laser tissue soldering (LTS).

BACKGROUND AND OBJECTIVE: Laser tissue soldering (LTS) using albumin and indocyanine green dye (ICG) is an effective technique utilized in various reconstructive surgical procedures. The purpose of this study was to describe in vivo and in vitro temperature profiles of an albumin-based solder while varying ICG concentration and laser power density (PD), and to describe immediate and short-term tensile strength measurements and histology of tissue with variable ICG concentrations and PD. STUDY DESIGN/MATERIALS AND METHODS: ICG ranged from 0.31 to 20 mg/mL while PD ranged from 3.2 to 63.7 W/cm(2). Direct solder temperature measurements were obtained at 5-second intervals during laser activation. Differential temperature measurements were determined within the dermis of rat skin and the overlying solder. Eighteen rats were subjected to 2.0-cm incisions (n = 113) created on the dorsal skin followed by closure with LTS at varying PD and ICG concentrations. ICG concentrations included 0.31, 2.5, and 20 mg/mL, while PD ranged from 8.0 to 63.7 W/cm(2). Tensile strength (TS) profiles were measured immediately and 10 days post-operatively. Histological examination was performed at the time of sacrifice. RESULTS: Temperature profiles of the ICG/albumin solder differed significantly only at the highest concentration of ICG (20 mg/mL), but showed statistically significant variability at different laser PD. Using solder color changes as an endpoint of LTS, average peak solder temperature ranged from 69 degrees C at a PD of 8.0 W/cm(2), 105 degrees -120 degrees C at PD 15.9-31.8 W/cm(2), and > 200 degrees C at PD > or = 47.7 W/cm(2). Peak intradermal temperatures remained below 50 degrees C at all PDs. Varying ICG concentration only had an effect on the immediate TS of wounds at the lowest power densities. Increasing PD resulted in statistically significant increases in immediate TS up to a PD of 23.9 W/cm(2) at an ICG concentrations of 0.31 and up to a PD of 15.9 W/cm(2) at a concentration of 2.5 mg/mL. Statistically insignificant decreases in 10-day would strength resulted from higher PD. Power densities > or = 23.9 W/cm(2) showed significant thermal injury upon histologic examination. CONCLUSIONS: Power density, not ICG concentration, is the primary determinant of solder and tissue temperature during LTS. Effective and reproducible laser tissue soldering may be achieved primarily by power density control when using diode laser and ICG-based albumin solder. Alterations in PD show the most direct and predictable effects on the healing properties of skin closed by LTS. Optimal laser wound closure occurs with an ICG of 2.5 mg/mL and at a PD between 15.9 and 23.9 W/cm(2).

Albumins↗
PubMed2001

Editorial comment.

Explore the source record for details and available documents.

Cohort Studies↗
PubMed2001

Antenatal hydronephrosis with postnatal resolution: how long are postnatal studies warranted?

We present 2 cases of antenatal hydronephrosis with initial normalization of postnatal studies. Both patients experienced late-onset (6 and 22 months) hydronephrosis secondary to ureteropelvic junction obstruction, necessitating surgical intervention. These cases raise questions about the need for late follow-up imaging in patients with apparent resolution of hydronephrosis diagnosed antenatally.

Age Factors↗
PubMed2001

Pseudohypoaldosteronism associated with ureterocele and upper pole moiety obstruction.

A 2-month-old girl was diagnosed with a febrile urinary tract infection. Subsequent studies revealed a right renal duplication anomaly with a poorly functioning upper pole moiety subtended by an intravesical ureterocele. The patient was also found to have hyperkalemia, hyponatremia, and elevated serum aldosterone. After antibiotic therapy, the urinary tract infection resolved, although the electrolyte and hormonal abnormalities persisted. At 4 months of age, a right upper pole heminephrectomy was performed. The patient's electrolyte and hormonal levels normalized. This case represents an unusual case of pseudohypoaldosteronism presenting with urinary tract infection and obstructed upper pole moiety that resolved after surgical intervention.

Anti-Bacterial Agents↗
PubMed2001

Increased incidence of hypospadias in small-for-gestational age infants in a neonatal intensive-care unit.

OBJECTIVE: To identify the incidence of hypospadias in children born prematurely and small-for-gestational age (SGA), and to compare this subgroup with infants of similar age and weight without hypospadias. PATIENTS AND METHODS: Records from the neonatal intensive-care unit (NICU) of a major metropolitan hospital active in labour and delivery were reviewed over a 3-year period, specifically examining newborns admitted with the diagnosis of SGA, defined as a birth weight of < 10th percentile for gestational age. In all, 154 patients were identified and their charts reviewed, recording the presence and severity of hypospadias, gestational age, birth weight, placental weight, cord length, cord vessels, maternal age, parity, multiple births, drug exposure and associated comorbidity. A control group of age- and weight-matched infants without hypospadias were also identified and compared. RESULTS: Of the 154 patients, 17 (11%) had hypospadias; the hypospadias was distal in nine, mid-shaft in four and proximal in four. The severity of hypospadias did not correlate with the degree of prematurity or weight for gestational age. Placental weight, fetal weight, fetal to placental weight ratio and cord length were all lower in the hypospadias group than in the control group, but the differences were not statistically significant. The maternal age was evenly distributed (median 32 years, range 20-43). Most mothers were multiparous and births were multiple in five of 17 (30%). Cryptorchidism (three) and inguinal hernia (three) were present in four of the infants. CONCLUSIONS: The incidence of hypospadias in SGA infants admitted to the NICU is > 10 times higher than that reported for the general population. There was a trend to lower placental and fetal weight in SGA infants with hypospadias than in the controls. This finding merits further evaluation using a larger population database and suggests that factors resulting in SGA infants occur at a critical point early in development, affecting both somatic and urethral development.

Adult↗
PubMed2001

Laser tissue soldering for hypospadias repair: results of a controlled prospective clinical trial.

PURPOSE: Laser tissue soldering has been shown to provide safe and effective tissue closure by creating an immediate leak-free anastomosis with minimal scar formation. We compared the results of laser tissue soldering and conventional suturing for hypospadias repair. MATERIALS AND METHODS: A consecutive group of 138 boys 4 months to 8 years old (mean age 15 months) was divided into a standard suturing (84) and a sutureless laser (54) hypospadias repair group. Urethral repair was defined as simple (Thiersch-Duplay or Snodgrass) and complex (onlay island flap or tube) in 101 and 37 cases, respectively. Laser tissue soldering was performed with 50% human albumin solder doped with 2.5 mg./ml. indocyanine green dye using an 808 nm. diode laser at 0.5 W. In the laser group sutures were used for tissue alignment only. At surgery neourethral and penile length, operative time for neourethral construction and the number of sutures or throws were measured. Postoperatively patients were examined for complications of wound healing, stricture or fistula. RESULTS: Mean patient age, urethral defect severity, type of repair, neourethral length and stenting time plus or minus standard error of mean were not significantly different in the 2 groups. Mean operative time was a fifth as long for laser tissue soldering in simple and complex hypospadias repair compared to controls (1.5 +/- 0.1 and 5.1 +/- 0.3 versus 8.5 +/- 0.8 and 26.7 +/- 1.7 minutes, respectively, p <0.001). The mean number of sutures used for tissue alignment in the laser group for simple and complex repair was significantly less than in controls (3.0 +/- 0.2 and 8.2 +/- 0.6 versus 8.5 +/- 0.8 and 23.2 +/- 1.5, respectively, p <0.001). All patients were followed a mean of 12 months (minimum 6, maximum 22). The complication rate was 4.7% in the laser group and 10.7% in controls with fistula in 2 of 54 cases, and fistula and meatal stenosis in 7 and 2 of 84, respectively. CONCLUSIONS: These preliminary results indicate that laser tissue soldering for hypospadias repair may be performed in almost sutureless fashion and more rapidly than conventional suturing. The ease of the laser technique and the lower complication rate in the laser group indicate that laser tissue soldering is an acceptable means of tissue closure in hypospadias repair.

Child↗
PubMed2001

Acute urinary retention in children.

PURPOSE: Acute urinary retention is relatively infrequent in children. There are a variety of causes that are poorly defined in the literature, and they differ greatly from those seen most frequently in adults. We review our experience with pediatric patients presenting with urinary retention to 2 major metropolitan children's hospitals. MATERIALS AND METHODS: Records from Egleston and Scottish Rite Hospitals for Children were reviewed for a 6-year period for the diagnosis of urinary retention. Urinary retention was defined as inability to empty the bladder volitionally for greater than 12 hours with a volume of urine greater than expected for age ([age in years + 2] x 30 cc) or a palpably distended bladder. All cases resulting postoperatively and believed secondary to surgical dissection, narcotic use or immobility, and children previously diagnosed with chronic neurological disorders and voiding dysfunction or with reduced mental status were excluded from study. The majority of these encounters were emergency department visits specifically for acute urinary retention. RESULTS: We identified 53 children meeting these criteria, including 37 boys 6 months to 17 years old and 16 girls 1 to 17 years old. Etiologies included neurological processes in 17%, severe voiding dysfunction in 15%, urinary tract infection in 13%, constipation in 13%, adverse drug effect in 13%, local inflammatory causes in 7%, locally invading neoplasms in 6%, benign obstructing lesions in 6%, idiopathic in 6%, combined urinary tract infection and constipation in 2%, and incarcerated inguinal hernia in 2% of cases. Adverse drug effects and dysfunctional voiding were implicated 3 times as often in males than females (16% versus 6% and 19% versus 6%, respectively). Urinary tract infections were 6 times more common in females (31% versus 5%). Constipation and local inflammatory processes were twice as common in females than males (19% versus 11% and 12% versus 5%, respectively). Local neoplasms, benign obstruction and idiopathic causes were found exclusively in males. CONCLUSIONS: Urinary retention in children is a relatively rare entity but there is a significant incidence of neurological abnormalities in this population. If a clear reason for this condition cannot be delineated based on history, physical examination and laboratory assessment, these patients should undergo prompt neurological evaluation and appropriate imaging studies.

Acute Disease↗
PubMed2000

Efficacy of nurse telehealth care and peer support in augmenting treatment of depression in primary care.

BACKGROUND: Primary care treatment of depression needs improvement. OBJECTIVE: To evaluate the efficacy of 2 augmentations to antidepressant drug treatment. DESIGN: Randomized trial comparing usual care, telehealth care, and telehealth care plus peer support; assessments were conducted at baseline, 6 weeks, and 6 months. SETTING: Two managed care adult primary care clinics. PARTICIPANTS: A total of 302 patients starting antidepressant drug therapy. INTERVENTIONS: For telehealth care: emotional support and focused behavioral interventions in ten 6-minute calls during 4 months by primary care nurses; and for peer support: telephone and in-person supportive contacts by trained health plan members recovered from depression. MAIN OUTCOME MEASURES: For depression: the Hamilton Depression Rating Scale and the Beck Depression Inventory; and for mental and physical functioning: the SF-12 Mental and Physical Composite Scales and treatment satisfaction. RESULTS: Nurse-based telehealth patients with or without peer support more often experienced 50% improvement on the Hamilton Depression Rating Scale at 6 weeks (50% vs 37%; P =.01) and 6 months (57% vs 38%; P =.003) and on the Beck Depression Inventory at 6 months (48% vs 37%; P =. 05) and greater quantitative reduction in symptom scores on the Hamilton scale at 6 months (10.38 vs 8.12; P =.006). Telehealth care improved mental functioning at 6 weeks (47.07 vs 42.64; P =.004) and treatment satisfaction at 6 weeks (4.41 vs 4.17; P =.004) and 6 months (4.20 vs 3.94; P =.001). Adding peer support to telehealth care did not improve the primary outcomes. CONCLUSION: Nurse telehealth care improves clinical outcomes of antidepressant drug treatment and patient satisfaction and fits well within busy primary care settings.

Adult↗
PubMed2000

The outcome of stopping prophylactic antibiotics in older children with vesicoureteral reflux.

PURPOSE: Accepted management of vesicoureteral reflux includes surgical correction or prophylactic antibiotics with the hope for resolution as the child grows. The physician must consider surgery when reflux does not resolve despite uneventful years on prophylactic antibiotics. An alternative is cessation of the antibiotics. We report on the outcome of children taken off antibiotics with persistent reflux. MATERIALS AND METHODS: During a 14-year period 51 children with documented reflux were taken off antibiotic prophylaxis. Selection criteria included children who were old enough to verbalize the symptoms of a urinary tract infection, and had normal voiding patterns, a minor history of infections and minimal or no renal scarring. Routine followup included nuclear cystography and renal sonography. RESULTS: A total of 40 girls and 11 boys maintained on antibiotics for a mean of 4.8 years were taken off prophylaxis and followed for an average of 3.7 years. Mean patient age when prophylactic antibiotics were stopped was 8.6 years. Reflux resolved in 10 children (19.6%). A urinary tract infection developed in 5 girls and 1 boy (11.8%) (mean age 11) an average of 2.3 years (range 4 months to 9.4 years) after antibiotic discontinuation. One child had symptoms consistent with cystitis and 5 had febrile urinary tract infections. All were treated with oral antibiotics and 5 had subsequent operations. No new renal scars developed. CONCLUSIONS: The majority of children did well following cessation of antibiotic prophylaxis despite persistent vesicoureteral reflux. Cessation of antibiotic prophylaxis is a reasonable option in a highly select patient population with reflux.

Adolescent↗
PubMed1998

Comparison of dermal and epithelial approaches to laser tissue soldering for skin flap closure.

BACKGROUND AND OBJECTIVE: Prior studies of laser tissue soldering (LTS) of epithelial skin have shown poor wound strength in the short-term; however, we hypothesize that greater tensile strength and healing properties will result from directing laser energy to the dermal aspect of the skin. The current study compares wound strength and histology in a rat skin flap model of epithelial and dermally applied LTS. STUDY DESIGN/MATERIALS AND METHODS: Skin flaps (2.5 x 4 cm) were raised and bisected on the dorsum of Sprague-Dawley rats. The center line of bisection was closed from a dermal approach by LTS (LTS-D, diode laser 15.9 W/cm2 + Columbia solder), the upper incision by epithelial LTS (LTS-E), and the lower incision by suturing (7-0 Vicryl). Wound skin strips (1-2 mm x 10 mm) were studied immediately (N = 14) and at 3 (N = 57), 7 (N = 31), and 10 (N = 28) days postoperatively and were subjected to tensiometric analysis. Histologic staining with hematoxylin and eosin and Mallory's trichrome methods were used to define wound architecture. RESULTS: No wound dehiscences were noted in any group. Greater immediate tensile strength was noted in wounds closed by LTS-D (521 +/- 61 g/cm2) versus LTS-E (342 +/- 65 g/cm2); however, this difference was not statistically significant (P = .08). By 3 days, both LTS-D (476 +/- 55 g/cm2) and LTS-E (205 +/- 37 g/cm2) maintained their initial strength; however, LTS-D and sutured (436 +/- 49 g/cm2) wounds were stronger (P < .05) than LTS-E. At 7 and 10 days, LTS-D (2,433 +/- 346 g/cm2 and 3,100 +/- 390 g/cm2) showed superior tensile strength (P < .05) compared to both LTS-E (1,542 +/- 128 g/cm2 and 2,081 +/- 219 g/cm2) and suturing (1,342 +/- 119 g/cm2 and 1,661 +/- 115 g/cm2). Histologic analysis of LTS-D wounds at 3 days showed full-thickness tissue apposition, complete epithelialization, and minimal inflammation or thermal injury. At 7 days, solder was present in the wounds. In contrast, LTS-E wounds at 3 days displayed lack of epithelialization secondary to thermal injury and partial-thickness tissue apposition. However by 7 days, epithelialization was complete with moderate scarring, and no solder was seen. Sutured samples appeared similar to LTS-D, except for poorer tissue apposition at the hypodermis. CONCLUSION: Our results show that skin flap wound healing after dermal LTS is superior to epithelial LTS and emphasizes the importance of site specificity in the utilization of this operative technique in reconstructive surgery.

Albumins↗
PubMed1998

Surgical management of the nonpalpable testis: the Children's Hospital of Philadelphia experience.

PURPOSE: The management of the nonpalpable testis permits an individualized operative approach. We analyze the results of surgical management of a large series of patients with a nonpalpable testis. MATERIALS AND METHODS: Between January 1986 and June 1994 we treated 1,866 boys with undescended testes. There were 447 testes (24%) that were not palpable at presentation. Intra-operative data on these patients were collected for age at presentation, bilateral testes position, testicular size, associated inguinal anomalies (vas, epididymis and processus vaginalis) and surgical approach. For intra-abdominal testes postoperative results of 2 surgical techniques, the Fowler-Stephens procedure and Koop orchiopexy (retroperitoneal mobilization of spermatic vessels and vas) were compared in 76 patients with at least 18 months of followup. RESULTS: Average patient age at presentation was 34 months with 63% presenting before age 48 months. Of the impalpable testes 58% were on the left side, 35% were on the right side and 7% were bilateral. At operation 181 testes (41%) were atrophic or absent, 91 (20%) were intra-abdominal with 14 (3.1%) bilateral, 136 (30%) were in the inguinal canal and 39 (9%) were in other locations, including 22 at the pubic tubercle, 2 in the upper scrotum, 13 in the superficial inguinal pouch and 2 in the perineum. Of the intra-abdominal group associated extratesticular malformations were identified in 36 cases (39%). Attachment of the vas deferens to the testis was abnormal in 23 of 64 cases (36%), including 10 that were completely detached and 13 with head or tail attachment only. Of the 91 evaluable cases in the intra-abdominal group 38 (42%) had been treated with the Fowler-Stephens repair (5 in 2 stages), 33 (36%) with inguinal orchiopexy and intraperitoneal dissection without dividing the spermatic vessels, 5 with 2-stage procedures and vessel preservation and 14 (15%) with orchiectomy. One testis was left in situ. The inguinal approach with intraperitoneal extension was successful in defining the testis location or blind-ending vas and vessels in 100% of the cases. A single operation to perform orchiopexy was successful in 92% of the cases. Overall, results were considered excellent or acceptable in 32 of 33 cases (97%) after Koop orchiopexy and 28 of 38 (74%) after the Fowler-Stephens orchiopexy. CONCLUSIONS: Nonpalpable testes accounted for 24% of the patients presenting with undescended testes. At surgical exploration 39% of impalpable testes were distal to the external inguinal ring, 41% were atrophic or absent and 20% were intra-abdominal. All cases were treated through a standard inguinal incision. These data provide evidence that the inguinal approach to orchiopexy with transperitoneal mobilization of the vas and vessels without transection is highly successful for the intra-abdominal cryptorchid testis and, to date, is the preferred technique for the management of the intra-abdominal undescended testis.

Child, Preschool↗
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

Skin flap closure by dermal laser soldering: a wound healing model for sutureless hypospadias repair.

OBJECTIVES: Laser tissue soldering (LTS) with the diode laser and human albumin-hyaluronate-indocyanine green solder is a safe and effective method of providing an immediate leak-free closure during hypospadias repair. In this report, we compare the physiology, histology, and immunohistochemistry of wound healing following LTS and suturing in a rat skin flap model. METHODS: A 4 x 5-cm skin flap was raised and bisected (4 cm) on the dorsum of 48 Sprague-Dawley rats. The central wound was either closed from a dermal approach by suturing or LTS or left open, and studied at 0, 3, 5, 7, 10, 14, and 21 days postoperatively. An intraoperative comparison was made between suturing and LTS with respect to operative time. Postoperatively, flaps were excised for tensiometric analysis, and sections were stained with hematoxylin-eosin to define wound architecture. Resting skin temperature, laser exposed temperature without solder, and maximum temperature with solder (one drop) were measured at the level of the deep dermis, superficial striated muscle layer, and within the solder. Mean peak temperatures were recorded during a 1-minute laser activation time. RESULTS: Mean continuous suturing time (4.9 +/- 1.1 minutes) was significantly (P < 0.001) faster than either LTS (7.7 +/- 0.77 minutes) or discontinuous suturing (8.2 +/- 0.62 minutes). Two seromas (sutured) and two instances of partial wound dehiscence (1 sutured, 1 LTS) were noted. Tensile strength was increased significantly (P < 0.001) for up to 5 days in the LTS group, but was equal to suturing at 7 and 10 days. Immediate tensile strength after LTS was equivalent to a 7-day healed wound. At 14 days, wounds initially left open and those closed by LTS were stronger than sutured wounds (P < 0.05). There was no evidence of thermal injury or foreign body reaction in the LTS group. Solder was incorporated within the dermis in all wounds at 21 days. Laser activation of solder resulted in significant increases in temperature at all three tissue levels: 65.0 +/- 5.2 and 69.9 +/- 6.8 degrees C in the deep and superficial skin (no significant difference between the two), and 101 +/- 15.6 degrees C within the solder (P < 0.001 versus superficial and deep skin). CONCLUSIONS: Our results indicate that sutureless dermal LTS of skin flaps provides increased tensile strength for up to 7 days, with relatively greater tensile strength provided within the first 3 days. Our laser technique does not appear to alter the normal wound healing process. Rather, solder-tissue interaction initially, and extracellular matrix infiltration of solder later, provide the basis for improved wound strength. For hypospadias repair using skin flaps, these wound attributes may permit sutureless surgery.

Animals↗