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Biomedical subjects

D A Canning

Publications and source records attributed to D A Canning.

At least 37 records · Page 2Linked to original sources
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↗
PubMed2000

Testicular volume does not predict germ cell count in patients with cryptorchidism.

PURPOSE: A germ cell count of less than 0.2 germ cell per tubule on the prepubertal biopsy of cryptorchid testes predicts abnormal spermiograms and decreased fertility in adulthood, and may be used to select patients for post-orchiopexy hormonal therapy. Testicular volume directly correlates with testicular function and spermiogenesis. We determined whether testicular volume would predict the total germ cell count accurately enough to replace testicular biopsy in the modern management of cryptorchidism. MATERIALS AND METHODS: At our hospital 723 patients younger than 9 years with cryptorchidism (unilateral in 619 and bilateral in 104) underwent orchiopexy and bilateral testicular biopsies. These patients had not undergone groin surgery or hormonal therapy previously and had at least 50 tubules in each testicular biopsy. Testicular volume and position, patient age and germ cell counts were analyzed. The generalized estimating equation was used to determine whether a correlation existed between testicular volume and germ cell count. RESULTS: The generalized estimating equation demonstrated a direct correlation between testicular volume and germ cell count. However, germ cell counts predicted from testicular volume varied widely within the 95% confidence intervals. Testes with less than 0.2 germ cell per tubule cannot be reliably distinguished from those with greater than 0.2 germ cell per tubule. CONCLUSIONS: Testicular volume does not accurately predict the germ cell count in patients with undescended testes, cannot be used to select patients for post-orchiopexy hormonal therapy and cannot replace testicular biopsy in the modern management of cryptorchidism.

Child↗
PubMed2000

The modern endoscopic approach to ureterocele.

PURPOSE: During the last 20 years the surgical approach to ureterocele has evolved from major open surgery to minimally invasive endoscopic puncture. We believe that the endoscopic approach decreases the need for open surgical procedures. We identified specific factors that predict the need for repeat surgery. MATERIALS AND METHODS: We reviewed the charts of 60 new patients with ureterocele treated with primary endoscopic incision between 1991 and 1995. Followup ranged from 4 to 62 months (mean 20). Mode of presentation, ureterocele location, associated vesicoureteral reflux and association of the ureterocele with a duplex system were evaluated. Ureterocele wall thickness was assessed subjectively via radiographic and cystoscopic methods, and categorized as thin, intermediate and thick. RESULTS: All 9 patients with a single system ureterocele had an intravesical ureterocele. No patient had associated reflux nor did any require a secondary open procedure. In 3 cases new onset ipsilateral reflux into the ureterocele spontaneously resolved. Of the 51 patients with a duplex system and associated ureterocele 19 (37%) required a secondary open procedure. The ureterocele was intravesical and ectopic in 22 (43%) and 29 (57%) cases, respectively. Reflux was associated with the ureterocele in 27 patients (53%), and 12 (44%) required a secondary open procedure. A total of 11 patients underwent ureteral reimplantation of 15 refluxing renal units and only 2 renal units required ureteral tapering. Reflux is no longer present in 14 of the 15 renal units (93%). Patients with a thick walled ureterocele required repeat puncture more frequently than those with a nonthick ureterocele. CONCLUSIONS: With the use of modern endoscopic techniques children with intravesical and single system ureteroceles require secondary open surgery less frequently than those with ectopic and duplex system ureteroceles. The mode of presentation does not predict the need for a repeat open procedure. Thick walled ureteroceles require repeat endoscopic puncture more frequently than thin and intermediate walled ureteroceles.

Female↗
PubMed1999

False-positive pregnancy test associated with gonadoblastoma.

Gonadoblastomas are known to be hormonally active tumors that occur in streak or dysgenetic gonads of patients with intersex abnormalities. Several reports document their ability to produce beta-human chorionic gonadotropin (HCG), but none have documented an elevated peripheral serum beta-HCG. We report on the case of a patient with pure gonadal dysgenesis with XY karyotype who was found to have an elevated peripheral serum beta-HCG after a positive pregnancy test. Knowledge of gonadoblastoma's potential to elevate serum beta-HCG levels may prevent unnecessary searches for other causes.

Adolescent↗
PubMed1999

Prognostic factors for long-term renal function in boys with the prune-belly syndrome.

PURPOSE: Renal failure develops in 25 to 30% of patients with the prune-belly syndrome. The clinical parameters associated with renal failure in this condition are not well understood. We determined which factors predict renal failure in children with the prune-belly syndrome. MATERIALS AND METHODS: We reviewed the records of 35 patients with the prune-belly syndrome who were treated at our hospital during a 37-year period. Nadir serum creatinine, time to nadir creatinine, presence or absence of a patent urachus, presence and severity of urinary tract infection, and renal failure were analyzed. RESULTS: Mean followup was 14 years 2 months. In 2 of the 17 patients with a nadir serum creatinine of less than 0.7 mg./dl. renal failure developed. Each of these 2 children also had clinical pyelonephritis and urosepsis. In 12 of the 13 patients nadir serum creatinine greater than 0.7 mg./dl. strongly predicted renal failure. Nonfebrile urinary tract infection within the first year of life was not predictive of outcome (p = 0.8) but a history of clinical pyelonephritis correlated with eventual renal failure (p<0.001). Urosepsis also correlated with renal failure (p = 0.008). Children with at least 1 normal kidney on renal ultrasound or renal scan had a significantly lower chance of renal failure (p<0.001). CONCLUSIONS: Bilaterally abnormal kidneys on ultrasound or renal scan, a nadir serum creatinine of greater than 0.7 mg./dl. and clinical pyelonephritis are prognostic for renal failure.

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

Acute epididymitis and urinary tract anomalies in children.

OBJECTIVES: To evaluate the incidence of urinary tract infection (UTI) and genitourinary malformations in children presenting with acute epididymitis. PATIENTS AND METHODS: Twenty-five children between 2 months and 14 years of age presenting with acute epididymitis underwent urine culture, abdominal ultrasound, voiding cystourethrography and, in selected cases, intravenous pyelography. Eleven patients were infants and 14 were older than 1 year. UTIs and genitourinary malformations were recorded. Fisher's exact test was used to compare the incidence in two age groups. A p value of less than 0.05 was considered significant. RESULTS: Seven UTIs and eight genitourinary malformations were diagnosed in infants, while in older children three UTIs and three malformations were discovered. Infants had a higher rate of associated UTI (p 0.049) and genitourinary malformations (p 0.017) than did older children. CONCLUSIONS: Our data show a close relationship between acute epididymitis in infants for both UTIs and genitourinary malformations. Every infant presenting with epididymitis would undergo a complete evaluation including abdominal ultrasound and voiding cystourethrography. In older children the need for imaging should be dictated by clinical history and physical findings.

Acute Disease↗
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↗