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Dive into the research topics where Michael G. Packer is active.

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Featured researches published by Michael G. Packer.


The Journal of Urology | 1994

An Alternative Approach to Myelodysplasia Management: Aggressive Observation and Prompt Intervention

Joel M.H. Teichman; Hal C. Scherz; Kyung Do Kim; Dae H. Cho; Michael G. Packer; George W. Kaplan

We have adopted an approach to the management of myelodysplasia patients which is contrary to that most commonly supported by the existing literature. We screen patients shortly after birth with ultrasound, urine culture and serum creatinine, and then follow patients at 3 to 6-month intervals with similar studies. Cystography and urodynamics are done only as required clinically or by a change in the sonogram. Clean intermittent catheterization is indicated for continence or medical reasons. With this approach of aggressive observation and prompt intervention, we observed a rate of renal deterioration (diminished function on renal scan or parenchymal loss on imaging studies) of 5%. Renal deterioration was associated statistically with urinary tract infections and reflux. Patients started on clean intermittent catheterization for medical indications had greater risk for renal deterioration than those started on it for continence. Renal deterioration occurred with equal frequency between patients with abnormal and normal urodynamic studies, that is urodynamics did not predict renal deterioration. Our data show a rate of renal deterioration similar to other reports. We believe that aggressive observation with prompt intervention for problems once identified represents a reasonable alternative to managing patients with myelodysplasia.


Urology | 1993

Genitourinary trauma in the pediatric patient

Irene M. McAleer; George W. Kaplan; Hal C. Scherz; Michael G. Packer; Frank P. Lynch

Trauma is the major source of mortality in the pediatric population. A retrospective review was performed on patients admitted to the Childrens Hospital and Health Center Trauma Program, San Diego, California, from August 1984 to May 1990. The purpose of this review was to evaluate pediatric trauma and to determine the best treatment and evaluation for genitourinary injuries. Blunt trauma was responsible for 98 percent of the injuries, with renal injuries being the most common. Bladder (7) and male urethral (2) injuries, and vaginal lacerations (8) also occurred. The most severe renal injuries (70%) and all significant bladder and urethral injuries were associated with gross hematuria. Hypotension was present in 31 percent of patients but rarely required surgical exploration for correction. Eighty-six patients underwent radiographic imaging. Computerized tomography (CT) scans demonstrated the most information about intra-abdominal solid organ injuries but was inaccurate in detecting bladder or urethral injuries. Genitourinary injury is common in children but rarely requires surgical management. CT scan is the best study to determine extent of solid-organ injury but is inferior to cystourethrography to diagnose bladder or urethral injuries.


The Journal of Urology | 1995

FERTILITY INDEX ANALYSIS IN CRYPTORCHIDISM

Irene M. McAleer; Michael G. Packer; George W. Kaplan; Hal C. Scherz; Henry F. Krous; Glenn F. Billman

We report on 226 male patients with cryptorchidism 6 months to 16 years old who underwent open testis biopsy at orchiopexy or orchiectomy at Childrens Hospital and Health Center from 1986 to 1990. A total of 355 specimens was obtained. Tissues were preserved in Bouins solution and examined on light microscopy for fertility index measurements. Several biopsies prepared using Bouins preserved paraffinized tissue and glutaraldehyde preserved semi-thin cut tissue were found to have comparable fertility index measurements. Of 184 patients with unilateral undescended testes 87 also underwent biopsy on the contralateral descended testis. A total of 42 patients had bilateral undescended testes. Age matched comparisons were made between fertility index measurements of the undescended testes and those previously reported of normal testes. Additional case matched comparisons of fertility indexes were made in those children who underwent biopsy of the undescended testis and its descended mate. Statistical analysis was performed using the independent Student t-test. When comparing undescended to descended testes, there was no significant difference in the fertility index of patients 1 year old or younger but fertility index differences were statistically significant in all of the other age groups. Fertility index measurements were significantly decreased from normal expected values in all age groups with unilateral cryptorchidism and in all but the 13 to 18-month-old group with bilateral cryptorchidism. The fertility index in the descended testis was similar to previously reported normal testis measurements in boys between 13 months and 6 years old. Our data suggest that potential fertility in the cryptorchid testis may be significantly impaired compared to normal testicular fertility regardless of patient age at the time of discovery of the undescended testis. The fertility index of the descended mates of unilateral undescended testes may also be somewhat impaired in certain age groups. Orchiopexy in the first year of life may be indicate to preserve available fertility potential.


The Journal of Urology | 1995

Correlation of Renal Biopsy and Radionuclide Renal Scan Differential Function in Patients with Unilateral Ureteropelvic Junction Obstruction

Jeffrey A. Stock; Henry F. Krous; John Heffernan; Michael G. Packer; George W. Kaplan

To understand better the relationship among radionuclide renal scan differential function, renal histology and the outcome of pyeloplasty we performed ipsilateral renal biopsies in a series of patients undergoing primary pyeloplasty. A total of 17 consecutive patients with unilateral ureteropelvic junction obstruction underwent renal biopsy at the time of pyeloplasty. Biopsies were examined systematically after sections were stained with hematoxylin and eosin, periodic acid, Schiff, Jones modified silver or Masson trichrome stains, and they were reviewed by 1 pathologist. Biopsy results were correlated with preoperative and postoperative radionuclide renal scan differential functions. Patient age ranged from 1 month to 7 years (mean 19.8 months). Renal biopsy was abnormal in 6 kidneys, of which 5 had a preoperative differential function of less than 33%. None of these kidneys had evidence of postoperative improvement in renal function on followup scans despite a technically successful result. All remaining 11 kidneys had normal biopsies and a preoperative differential function of greater than 44%. We conclude from these data that patients with ureteropelvic junction obstruction with a differential function of less than 35% have a high probability of significant histological changes on biopsy and a low probability of postoperative improvement in differential function.


The Journal of Urology | 1987

Ipsilateral Ureteroureterostomy and Pyeloureterostomy: A Review of 15 Years of Experience With 25 Patients

Thomas K. Huisman; George W. Kaplan; William A. Brock; Michael G. Packer

We reviewed our 15-year experience with pyeloureterostomy and ureteroureterostomy in 25 children with ureteral duplication. Pyeloureterostomy was performed in 5 patients, including 4 with reflux and 1 with upper pole obstruction. The results were good in 4 and in 1 patient postoperative anastomotic obstruction developed. Ipsilateral ureteroureterostomy was performed in 20 patients, including 8 with reflux into 1 or both ipsilateral ureters, 7 with obstructed ectopic upper pole ureters without ureterocele, 4 with ectopic ureteroceles and 1 with incomplete ureteral duplication and obstruction of the common distal ureteral segment. At followup, which ranged from 3 months to 6 years, 17 patients had good postoperative results as demonstrated by improved upper tract drainage and absence of reflux. Of 6 patients who underwent simultaneous ipsilateral ureteral reimplantation at the time of ureteroureterostomy postoperative reflux was noted in 1, necessitating a second procedure. Ureteral stumps were left in 13 patients. Postoperative urinary infection occurred in only 3 of these patients, all as single episodes and 2 associated with persistent contralateral reflux. Significant luminal disparity at the time of ureteroureterostomy was noted in 18 patients and did not adversely affect results.


The Journal of Urology | 1990

Microvascular autotransplantation of the intra-abdominal testis.

Clanton B. Harrison; George W. Kaplan; Hal C. Scherz; Michael G. Packer; Jonathan W. Jones

The operative management of intra-abdominal testes is controversial, largely because there is no method of orchiopexy that can reliably produce good results. We report our results on the use of microvascular autotransplantation of intra-abdominal testes. We performed 12 autotransplants in 10 boys ranging in age from 10 months to 14 years (median age 30 months). In each instance the testis had been localized previously by laparoscopy or it was known to be intra-abdominal and was believed to be grossly normal in appearance. The vascular anastomoses of the spermatic to the inferior epigastric vessels were performed by an experienced microvascular surgeon using 10-zero nylon suture and 40 times magnification. Biopsies were taken at operation in 9 patients. Followup of 6 to 30 months is available in 7 patients and all 8 testes are palpably normal and in good scrotal position. This approach is feasible even in small children and the results seem to be superior to the expected results reported with division of the spermatic vessels.


Urology | 1996

Reduction of paraphimosis with hyaluronidase

Catherine R. deVries; Alan K. Miller; Michael G. Packer

The use of hyaluronidase facilitates reduction of paraphimosis. It acts by dispersing extracellular edema, permitting easy reduction of the foreskin. Its use is applicable both in the hospital and outpatient setting. Hyaluronidase is widely available and keeps well if refrigerated. It is effective for children and adults.


The Journal of Urology | 1994

Is Urinary Tract Screening Necessary for Patients with Cerebral Palsy

Philip P. Brodak; Hal C. Scherz; Michael G. Packer; George W. Kaplan

Patients with cerebral palsy are prompted to seek urological evaluation when urinary tract infection, socially unacceptable incontinence or hematuria occurs. We attempted to determine the prevalence of urinary tract structural changes by prospectively screening on sonography the kidneys and bladder of 90 patients 1 to 25 years old (mean age 8 years) who had cerebral palsy with or without urological symptoms. Uncooperative patients or those who would require sedation were excluded. Of the patients 66 were incontinent and used diapers, 18 were completely dry and 6 had nocturnal enuresis with daytime dryness. Sonographic abnormalities were detected in 7 patients, including renal size discrepancy in 2 (1 with severe scoliosis and 1 with a history of renal artery thrombosis), mild to moderate hydronephrosis with thickened bladders suggestive of neurogenic bladder dysfunction in 3 and a nonvisualized kidney in 2. However, repeat sonography confirmed 2 normal kidneys in the latter patients. Thus, urinary tract abnormalities were detected unexpectedly in 2% of patients studied. This relatively low proportion suggests that routine urinary tract screening in cerebral palsy patients may not be warranted.


The Journal of Urology | 1988

Post-Hypospadias Repair Urethral Strictures: A Review of 30 Cases

Hal C. Scherz; George W. Kaplan; Michael G. Packer; William A. Brock

During a 16-year period we treated 30 patients with urethral stricture after hypospadias repair. Of the patients 16 were treated successfully with 1 procedure, while 13 required 2 or more procedures and 1 was lost to followup. A good result was achieved in 83 per cent of the patients. Fourteen patients who presented with symptoms attributable to the stricture within 3 months of the original operation for hypospadias were designated as having early strictures. Those with strictures presenting later than 3 months were considered to have late strictures. Manipulative therapy (dilation and direct vision internal urethrotomy) was successful in 55 per cent of the early strictures but in only 16 per cent of the late strictures. An open operation was performed primarily in some cases or after failed manipulation in others and it was successful in 79 per cent. All 4 failures of open procedures were salvaged with manipulative therapy. We conclude that treatment of post-hypospadias repair urethral strictures initially should be manipulative. Open repair usually will be successful but should be reserved for difficult strictures, late strictures or failures of manipulation.


The Journal of Urology | 1990

Diagnostic Pneumoperitoneum for the Detection of the Clinically Occult Contralateral Hernia in Children

Clanton B. Harrison; George W. Kaplan; Hal C. Scherz; Michael G. Packer

The detection and management of occult contralateral hernia in children who present with a clinically evident unilateral hernia have evoked controversy. Routine use of herniography, intraoperative probing of the contralateral inguinal area and routine or selective exploration of the contralateral groin all have their advocates and detractors. During the last 5 years we have used intraoperative pneumoperitoneum and we report our experience in 64 patients 3 months to 9 years old. A retrospective analysis of the data revealed that pneumoperitoneum was negative in demonstrating a contralateral inguinal hernia in 59 of 64 patients (92%). Contralateral exploration was not performed in patients in whom pneumoperitoneum was negative. All 5 patients who tested positive had an indirect inguinal hernia upon contralateral exploration and all 5 were less than 3 years old. Patients who had a negative pneumoperitoneum were followed for up to 5 years and only 1 (1.8%) false negative examination was discovered. Pneumoperitoneum is a safe, effective means to evaluate the contralateral groin for occult hernia at the time of unilateral hernia repair in children.

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George W. Kaplan

Boston Children's Hospital

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Henry F. Krous

University of California

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Paul C. Hajek

University of California

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Robert F. Mattrey

University of Texas Southwestern Medical Center

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