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Biomedical subjects

Lane S Palmer

Publications and source records attributed to Lane S Palmer.

11 recordsLinked to original sources
PubMed2006

Pediatric urologic imaging.

Significant advances have been made in the imaging of the urinary tract in children. The trio of renal-bladder ultrasound, voiding cystourethrogram (VCUG), and nuclear scintigraphy dominate this imaging. CT and MRI, however, are rising in utility to supplement these studies and in some cases provide the definitive imaging. This article provides the radiographic findings associated with the most common pediatric urologic problems and some less common anomalies. The focus will be on ultrasound, VCUG,and nuclear studies with CT and MRI discussed as pertinent.

Child↗
PubMed2005

The use of betamethasone to manage the trapped penis following neonatal circumcision.

PURPOSE: The trapped penis results from cicatricial scar formation over the glans after circumcision. Management of this problem has been surgical either by incision of the cicatrix or formal surgical reconstruction. We report a series of neonates with trapped penises which were effectively managed primarily with topical steroid cream with operative intervention reserved for failed cases. MATERIALS AND METHODS: A retrospective study of 14 neonates who presented with a trapped penis treated with topical betamethasone cream was performed. Each child underwent topical application of 0.05% betamethasone 3 times daily for 3 weeks in conjunction with manual retraction that continued after the steroid course. The need for surgical intervention was assessed during and after the treatment period. RESULTS: All 14 boys were evaluated by the pediatric urologist within 4 weeks of circumcision. Each child had a trapped penis with a dense cicatrix of the residual foreskin distal to the glans. All parents were compliant with the regimen. There were no untoward effects of topical steroid application. Following therapy 11 boys (79%) demonstrated softening of the cicatrix with easy exposure of the glans in 2 and mild persistence of the cicatrix amenable to vertical relaxation incision in 2. The cicatrix persisted in 3 boys (14%) who required formal operative repair at ages 5 to 8 months. CONCLUSIONS: The combination of topical betamethasone and manual retraction is effective in managing the trapped penis. This combination may affect complete resolution of the condition in the majority of patients. Otherwise, this regimen may release the closing cicatrix and allow for simple incision of the constricting phimotic ring, thus reducing the need for formal surgical repair.

Administration, Topical↗
PubMed2005

Renal pelvis cuff pyeloplasty for ureteropelvic junction obstruction for the high inserting ureter: an initial experience.

PURPOSE: Ureteropelvic junction (UPJ) obstruction can result from a high inserting ureter without intrinsic ureteral obstruction. We describe our initial experience using a renal pelvis cuff pyeloplasty technique to treat this cause of UPJ obstruction. MATERIALS AND METHODS: We reviewed our experience regarding all children who underwent renal pelvis cuff pyeloplasty. All patients had Society for Fetal Urology grade 3 to 4 hydronephrosis on ultrasonography and radiographic confirmation of UPJ obstruction by diuretic mercaptoacetyltriglycine renography. Pyeloplasty was performed through a flank incision. A circumferential incision was made of the renal pelvis proximal to the insertion site of the ureter into the renal pelvis. Next, a catheter was passed through the UPJ to ensure uniform patency. The cuff of pelvis with the attached ureter was then sutured to the dependent portion of the pelvis. Postoperative resolution of the obstruction was evaluated by ultrasonography and mercaptoacetyltriglycine renography. RESULTS: A total of 11 children (6 boys and 5 girls) underwent renal cuff pyeloplasty for UPJ obstruction due to a high inserting ureter. Median patient age was 6 months (range 2.5 months to 2.4 years) and median followup was 11 months (8 months to 3.4 years). All patients were discharged home within 2 days postoperatively. No intraoperative or postoperative complications were noted. All patients exhibited resolution of UPJ obstruction on followup radiographs. CONCLUSIONS: Renal pelvis cuff pyeloplasty is a surgical technique for UPJ obstruction resulting from a high inserting ureter without intrinsic ureteral obstruction. The procedure was straightforward with good results and without complications in this initial experience.

Anastomosis, Surgical↗
PubMed2004

Prevention of renal fibrosis by spironolactone in mice with complete unilateral ureteral obstruction.

PURPOSE: Recent data suggest that aldosterone directly mediates cardiac fibrosis and hypertensive nephrosclerosis. We conducted experiments to determine whether administration of spironolactone, a mineralocorticoid receptor antagonist, reduced renal fibrosis in an experimental model of obstructive uropathy. MATERIALS AND METHODS: Complete unilateral ureteral obstruction (UUO) was created surgically in 8 to 10-week-old male C57BL/6 mice by placing sutures around the right ureter. Spironolactone (50 mg/kg/daily) or 1% dimethyl sulfoxide vehicle was administered by subcutaneous injection for 1 to 2 weeks, and renal fibrosis was assessed by measuring trichrome staining and type I collagen deposition in the kidney. RESULTS: UUO lasting 1 week was associated with minimal parenchymal damage and spironolactone had no demonstrable effect. In contrast, administration of the mineralocorticoid antagonist (8 mice) for a 2-week period significantly reduced renal fibrosis in the obstructed kidney, compared to mice given the dimethyl sulfoxide vehicle (9). The beneficial effect of spironolactone treatment was not associated with any changes in serum potassium or aldosterone concentration, or urinary concentrations of sodium or potassium. CONCLUSIONS: Administration of spironolactone reduced renal fibrosis in mice with UUO. These findings suggest that clinical trials are warranted to determine the efficacy of aldosterone antagonists in conjunction with angiotensin converting enzyme inhibitors and/or angiotensin receptor blockers as renoprotective agents in patients with obstructive uropathy.

Animals↗
PubMed2003

Laparoscopic orchiopexy: report of 203 cases with review of diagnosis, operative technique, and lessons learned.

BACKGROUND AND PURPOSE: Proper management of the nonpalpable testicle requires an accurate diagnosis. Laparoscopic orchiopexy (LO) has become the standard for diagnosis and treatment. We classified the location of nonpalpable testicles, reviewed the technique of LO in detail, and report the results of our series, the largest described to date. PATIENTS AND METHODS: We compiled the records of all cryptorchid patients seen between 1994 and 2002. Those with testicles located near the internal inguinal ring and those with nonpalpable testicles underwent laparoscopy and LO in the same session. The 173 patients underwent 203 procedures, all performed by the senior authors. RESULTS: The undescended testicles were right-sided in 33% of patients, left-sided in 53%, and bilateral in 14%. Six testicles were excluded because of hypotrophy (N=4) or agenesis of the vas deferens (N=2). At laparoscopy, 58% of the testicles were at the iliac vessels or higher (high intra-abdominal), 22% were between the iliac vessels and the internal ring (low intra-abdominal), 16% were peeping, 3% were intracanicular, and 1% were retrovesical. Standard LO was performed in 70.5% of the patients, with the remainder being treated by laparoscopic Fowler-Stephens orchiopexy. There have been four cases of testicular atrophy, all after Fowler-Stephens procedures. Two were virgin gonads, and the other two had previously been subjected to extensive orchiolysis. Only 3% of the patients required repeat surgery because of an unsatisfactory testicular location. CONCLUSION: The reported success rate for LO of intra-abdominal testicles has far exceeded that of open repair (95% v 76%). It is our belief that minimal manipulation of the testicle during dissection, a wider peritoneal window, and sparse use of electrocautery will result in adequate testicular position even for high intra-abdominal gonads with minimal risk of atrophy.

Atrophy↗
PubMed2003

Complications of pediatric urological laparoscopy: mistakes and risks.

PURPOSE: We evaluate the results and complications of laparoscopic urological procedures in children. MATERIALS AND METHODS: In a 3-year period 4,350 laparoscopic procedures were performed at 8 Italian centers of pediatric surgery. We analyzed only the data of urological procedures for a total of 701 laparoscopic operations on patients 1 month to 14 years old. The indications for surgery were cryptorchidism in 414 cases, varicoceles in 159, ambiguous genitalia in 37, total nephrectomy in 34, partial nephrectomy in 4, adrenalectomy in 3 and other diagnostic procedures in 50. We adopted a retroperitoneoscopic approach in 72 cases (10.3%) and a laparoscopic approach in 629 (89.7%). Patient records were analyzed to search for any complication that may have occurred during the laparoscopic procedure and assess how they were managed. RESULTS: We recorded 19 complications (2.7%) in our series, of which 6 required conversion to open surgery and 13 did not. There was no mortality. At a maximum followup of 4 years all children were alive and had no problems related to the laparoscopic complications. CONCLUSIONS: Our study shows that pediatric laparoscopic urological surgery has an acceptable rate of complications with no mortality. We believe that routine use of open laparoscopy in pediatric patients is a key factor to help avoid complications. Most complications can be avoided with surgeon and team experience, together with proper compliance with the indications for surgery.

Adolescent↗
PubMed2003

The role of gadolinium enhanced magnetic resonance imaging for children with suspected acute pyelonephritis.

PURPOSE: The diagnosis of pyelonephritis is primarily clinical. However, the history and physical findings can be confusing in children, leading to adjunctive nuclear renal cortical scintigraphic studies (99mtechnetium dimercapto-succinic acid [DMSA]) to confirm the diagnosis. Nonetheless, ambiguity occurs when differentiating between acute pyelonephritis and chronic scarring. We report our initial experience with gadolinium enhanced inversion recovery magnetic resonance imaging (MRI) to diagnose acute pyelonephritis. MATERIALS AND METHODS: Nine patients 7 months to 18 years old (mean age 81 months) underwent MRI to confirm radiographically a clinical suspicion of acute pyelonephritis. All patients had at least 1 prior episode of clinical pyelonephritis. Data were collected to determine whether acute pyelonephritic changes could be differentiated from chronic pyelonephritis on the basis of MRI characteristics. RESULTS: Of the 9 patients 4 were identified as having acute pyelonephritis on MRI (persistently high signal intensity after gadolinium), 2 demonstrated evidence of postpyelonephritic scar (parenchymal loss without change in signal intensity), 1 had evidence of acute pyelonephritis and chronic changes, and 2 had a completely normal examination (decreased signal intensity after gadolinium). At our institution the billable cost of MRI to the patient is $1,329, while the billable cost of 99mtechnetium DMSA is $1,459. All patients younger than 6 years required intravenous sedation for MRI, whereas 70% of those younger than 6 years require intravenous sedation for DMSA scanning at our institution. MRI provided greater anatomical detail regarding the renal architecture without radiation exposure, and allowed the unambiguous diagnosis of acute versus chronic pyelonephritis scar in a 1-time (versus often multipart for DMSA) imaging study. CONCLUSIONS: In cases where adjunctive imaging studies are useful to make a diagnosis gadolinium enhanced inversion recovery magnetic resonance imaging allows the detection of acute pyelonephritis rapidly, cost-effectively and safely in the pediatric population.

Acute Disease↗
PubMed2002

Nitric oxide in obstructive uropathy: role of endothelial nitric oxide synthase.

PURPOSE: Nitric oxide (NO) ameliorates fibrosis in experimental obstructive uropathy. Previously, we demonstrated that renal fibrosis was decreased after 2 weeks of unilateral ureteral obstruction in inducible nitric oxide synthase (iNOS) knock-out mice given L-arginine supplemented drinking water. We proposed that the 2 constitutive isoforms of nitric oxide synthase (NOS) mediated down-regulation of renal fibrosis in response to prolonged ureteral obstruction. To determine the specific role of endothelial NOS (eNOS) versus neuronal NOS in modulating renal fibrosis due to obstructive uropathy, we evaluated renal injury following unilateral ureteral obstruction in C57BL/6J mice subjected to biochemical inhibition of the constitutive isoforms of NOS and in eNOS knockout mice. MATERIALS AND METHODS: Four groups of C57BL/6J mice were studied. Complete unilateral ureteral obstruction was created by ligating the right ureter at age 8 weeks. A single daily intraperitoneal injection of 30 mg./kg. S-methyl-L-thiocitrulline (SMLT), a selective neuronal and endothelial NOS inhibitor was started 24 hours before ureteral obstruction and administered to half of the study animals. SMLT treated mice and control animals were further subdivided to receive either regular tap water or 1% L-arginine (weight/volume) supplemented water after unilateral ureteral obstruction. Animals were sacrificed on postoperative day 3, 7 or 14. In addition, eNOS knockout mice with unilateral ureteral obstruction were given tap water or L-arginine supplemented water to drink and sacrificed after 14 days. Urine specimens from the bladder and the obstructed renal pelvis along with serum were collected. Nitrite level in each fluid was determined. Renal morphology and cortical thickness were assessed in the normal and obstructed kidneys. Interstitial fibrosis was evaluated using trichrome stain. RESULTS: SMLT was well tolerated by C57BL/6J mice. Serum nitrite levels and nitrite excretion in bladder urine were similar in all SMLT treated groups throughout the duration of unilateral ureteral obstruction. A reduction of pelvic urine nitrite levels by 89%, 68% and 48% versus bladder urine nitrite levels was observed after 3, 7 and 14 days of unilateral ureteral obstruction (p <0.05). Administration of SMLT resulted in a significant increase in bladder urine nitrite level at 7 days and in pelvic urine nitrite levels at 14 days. No significant histological differences in the obstructed kidney were seen after 3, 7 or 14 days of unilateral ureteral obstruction in SMLT treated versus control mice regardless of whether they received tap water or L-arginine supplemented drinking water. In eNOS knockout mice with unilateral ureteral obstruction for 14 days L-arginine supplementation had no effect on pelvic urine nitrite levels and did not alter renal histopathology or cortical thickness. CONCLUSIONS: NO production is decreased in the obstructed kidney in mice with unilateral ureteral obstruction. Biochemical inhibition of constitutive NOS did not modulate renal injury after 14 days of unilateral ureteral obstruction. In contrast to previous findings with iNOS knockout mice, dietary supplementation with L-arginine had no effect on the degree of fibrosis in the obstructed kidney in SMLT treated C57BL/6J or eNOS knockout mice. We conclude that NO derived from eNOS within the kidney has a pivotal role in protecting against renal fibrosis in response to unilateral ureteral obstruction.

Animals↗
PubMed2002

Biofeedback therapy expedites the resolution of reflux in older children.

PURPOSE: In older children the spontaneous resolution rate of low grade vesicoureteral reflux is low and currently its management is controversial in regard to surgery versus prophylaxis versus observation alone. Bladder dysfunction in children with neurogenic bladders and to a less declarative degree in neurologically intact children has a role in the etiology or persistence of reflux. We determine the impact of biofeedback therapy on neurologically intact children with vesicoureteral reflux and detrusor-sphincter dyssynergia. MATERIALS AND METHODS: Vesicoureteral reflux was detected by voiding cystourethrography in children evaluated for urinary tract infections. Children with breakthrough infections or dysfunctional voiding based on history underwent uroflowmetry with concomitant patch electromyography of the external sphincter. Dyssynergia was defined as increased or steady electromyography activity during micturition. Biofeedback was initially performed weekly and the interval increased as indicated. The goals were to eliminate dyssynergia and reduce or eliminate post-void residual urine. Voiding cystourethrography was performed 1 year later to determine the status of the reflux. Ureteral reimplantation was performed during the period of biofeedback when indicated. RESULTS: From February 1997 to March 2001, 25 children 6 to 10 years old (mean age 9) with vesicoureteral reflux and detrusor-sphincter dyssynergia were treated with biofeedback therapy. There were 31 units (5 bilateral) with reflux, which was grade I in 10, II in 15, III in 5 and IV in 1. Children underwent an average of 7 sessions of biofeedback (range 2 to 20). On followup voiding cystourethrography, vesicoureteral reflux resolved in 17 units (55%), grade improved in 5 (16%) and reflux remained unchanged in 9 (29%). All cured vesicoureteral reflux was grade I (8 cases) or II (9). Four children (5 renal units) underwent reimplantation. In cured children there were no breakthrough infections during or since therapy and post-void residual urine decreased from an average of 40% before to 10% after therapy. Symptoms of urgency, daytime wetting and hoarding of urine improved or were eliminated in all children with resolved vesicoureteral reflux. CONCLUSIONS: Treating external detrusor-sphincter dyssynergia in older children with low grade vesicoureteral reflux, with biofeedback results in 1-year resolution rates that are considerably greater than historical resolution rates. External detrusor-sphincter dyssynergia should be screened for in children when surgery or discontinuation of chemoprophylaxis is considered so that biofeedback can be started.

Biofeedback, Psychology↗
PubMed2002

The "long Snodgrass": applying the tubularized incised plate urethroplasty to penoscrotal hypospadias in 1-stage or 2-stage repairs.

PURPOSE: The technique of tubularized incised plate urethroplasty (Snodgrass modification) has gained wide acceptance for hypospadias repair. The reported experience with this surgical modification has been primarily in cases of distal hypospadias. We applied this technique to cases of penoscrotal hypospadias and incised the urethral plate for its entire distance. MATERIALS AND METHODS: In the last 24 months 21 boys 7 months to 8 years old with penoscrotal hypospadias were treated with a Thiersch-Duplay urethroplasty using the Snodgrass modification. The procedure was performed in 7 patients as a primary repair and in 14 at stage 2 of the 2-stage repair. The entire length of the urethral plate was incised along the midline in primary repairs, and the skin flaps and residual urethral plate were incised in the 2-stage repairs. The neourethra was tubularized over a 5 or 8Fr catheter. A layer of de-epithelialized tissue from the dorsal prepuce was used to cover the neourethra. No patient required skin flap to complete the urethroplasty. The urethral stent was removed in 7 to 10 days postoperatively. RESULTS: Of the 21 patients 19 (90%) required no other surgery as the repair provided a normal appearing penis (straight, terminal meatus, cosmetics) without complications such as meatal stenosis, fistula and diverticula, and voiding with a well directed full stream. One child had dehiscence of the glanular portion of the repair and 1 child had a pinpoint fistula, both of which were repaired successfully at a later date. Followup ranges from 5 to 12 months. CONCLUSIONS: The "long Snodgrass" modification to a Thiersch-Duplay repair is an effective technique for penoscrotal hypospadias as a single and 2-stage procedure. The success and complication rates are excellent in the short term. Longer term complications, such as strictures and diverticula, need to be assessed in the future.

Child↗