Search PubMed⌕ Search

Biomedical subjects

Carson Wong

Publications and source records attributed to Carson Wong.

12 recordsLinked to original sources
PubMed2006

Laparoscopic transabdominal transvesical vesicovaginal fistula repair.

BACKGROUND AND PURPOSE: Transabdominal transvesical repair has been the standard treatment for difficult vesicovaginal fistulae. We describe a laparoscopic transvesical technique that minimizes operative morbidity while adhering to the principles of transabdominal repair as described by O'Conner. TECHNIQUE: The patient is placed in the lithotomy position using Allen stirrups, and bilateral 5F open-ended ureteral catheters are placed cystoscopically. Using four laparoscopic ports, the prevesical space is accessed. The bladder is bivalved down to the fistula, and stay sutures are placed at the bladder edges for exposure. The fistulous tract and adjacent fibrotic tissue are excised, and the bladder and vagina are closed separately with single layers of full-thickness interrupted 2-0 Vicryl sutures. An omental flap is interposed between suture lines in the bladder and vagina. The ureteral catheters are sequentially removed on the first and second postoperative days. A gravity cystogram is performed 3 weeks postoperatively; if it is normal, the urethral catheter is removed. RESULTS: This procedure has been performed on two consecutive patients who had failed prior Latzko repairs. Both patients were discharged 2 days postoperatively without complications. At a follow-up of 41 months in the first patient and 39 months in the second, no fistula recurrence has been seen. CONCLUSIONS: Laparoscopic transvesical vesicovaginal fistula repair appears to be a safe and effective procedure that adheres to the principles of a transabdominal transvesical fistula repair while decreasing morbidity and improving cosmesis. Continued follow-up is required to determine its long-term efficacy compared with the accepted open transabdominal and transvaginal approaches.

Abdomen↗
PubMed2005

Screening and identification of differentially expressed transcripts in circulating cells of prostate cancer patients using suppression subtractive hybridization.

BACKGROUND: Tumor metastasis and changes in host immunosurveillance are important components in cancer development. Tumor cell invasion into the bloodstream is an essential step for systemic metastasis. Currently, the detection of tumor cells in the circulation is mainly dependent upon the utilization of known epithelial cell markers. However, expression of these molecules is not limited to cancer patients; healthy people also have a small number of epithelial cells in their circulation. Utilizing these markers to detect circulating tumor cells (CTCs) cannot adequately explain the mechanisms of tumor cell survival or their development of metastatic potential in peripheral blood. The immune system can also evolve along with the cancer, actually promoting or selecting the outgrowth of tumor variants. Unfortunately, both metastasis and immunosurveillance remain mysterious and are debatable because we have yet to define the molecules that participate in these processes. We are interested in identifying the existence of expressed genes, or mRNA species, that are specifically associated with circulating cells of cancer-bearing patients using prostate cancer (PCa) as a model. RESULTS: We established two comprehensive subtracted cDNA libraries using a molecular technique called suppression subtractive hybridization. This technique selectively amplifies transcripts that are specifically expressed in circulating cells of either PCa patients or healthy men. Following sequencing reaction, we showed that 17 out of 23 (73.9%) sequenced clones did not match any mRNAs in the GenBank database. This result suggests that genes associated with alterations in circulating cells of cancer-bearing patients are largely unknown. Semi-quantitative RT-PCR confirmed that two genes are up-regulated in circulating cells of PCa patients, whereas another two genes are down-regulated in the same patients. CONCLUSION: The comprehensive gene expression analysis is capable of identifying differentially expressed genes in circulating cells of healthy men and PCa patients. We did not attempt to enrich specific cell types in this study because phenotypes of CTCs and subsets of leukocytes participating in immunosurveillance remain largely unknown. Continuous studies of these differentially expressed genes will eventually lead us to understand the mechanisms involved in tumor metastasis and immune modulation during cancer development.

Biomarkers, Tumor↗
PubMed2005

Laparoscopic renal surgery in infants 10 kg or less.

BACKGROUND AND PURPOSE: Major laparoscopic urologic procedures have been successful in children, but few reports of laparoscopic surgery in infants weighing <10 kg exist. We present our series of laparoscopic renal procedures in such patients. PATIENTS AND METHODS: The hospital records of 17 consecutive patients (9 boys, 8 girls) with a median age of 7 months (range 1-25 months) weighing a mean of 8.5 kg (range 4.2-10 kg) who had undergone laparoscopic renal surgery (nephrectomy, partial nephrectomy, nephroureterectomy) between March 1999 and January 2004 were reviewed. Twelve patients underwent laparoscopic nephrectomy, three laparoscopic nephroureterectomy, and two laparoscopic heminephrectomy. Additional procedures were performed concomitantly in three patients. RESULTS: All operations had minimal estimated blood loss. Excluding those patients who underwent additional procedures, the mean operative time was 138 minutes (range 77-229 minutes). The postoperative hospitalization was 23 hours or less in all except two patients, both of whom had undergone additional procedures. The only complication was an intraoperative diaphragmatic injury that was repaired laparoscopically without sequelae. There were no delayed complications, and by 2 weeks postoperatively, all patients were recovered fully. CONCLUSION: Major laparoscopic urologic procedures can be performed in infants weighing <10 kg with low morbidity and rapid recovery.

Body Weight↗
PubMed2004

Application of strict radiologic criteria to define success in laparoscopic pyeloplasty.

PURPOSE: To review our experience and utilize rigorous radiologic criteria to establish success in laparoscopic pyeloplasty. PATIENTS AND METHODS: The hospital records of consecutive adult patients who underwent laparoscopic pyeloplasty for ureteropelvic junction (UPJ) obstruction during a 5-year period at our institution were reviewed. We identified 47 candidates for study inclusion. With one open conversion secondary to excessive fibrosis and one patient requiring repeat laparoscopic pyeloplasty for recurrence, 46 patients with 47 renal units were included for analysis. Thirteen renal units had prior surgery for UPJ obstruction. Preoperative and postoperative symptomatology were compared to determine subjective outcome. Mercaptoacetyltriglycine (MAG3) nuclear renography was performed preoperatively and postoperatively to assess differential renal function (DRF) and obstruction, defined as a T1/2 -20 minutes, and evaluate objective success. There were 34 dismembered and 13 Y-V pyeloplasties. RESULTS: The mean operative time was 341.6 minutes (range 200-717 minutes). The mean preoperative T1/2 was 48.4 minutes (range 14 minutes-xc), with a mean DRF of 39.8% (range 22%-60%). The mean postoperative T1/2 was 9.32 minutes (range 2-27 minutes), and the mean DRF was 39.5% (range 7%-57%). The average length of hospital stay was 2.25 days (range 1-3 days). At a mean follow-up of 19.93 months (range 2-55 months), the subjective success rate was 95.7%, and the objective success rate was 93.6%. CONCLUSION: Even when using strict radiologic criteria to define success, laparoscopic pyeloplasty is found to be similar to open surgery in its efficacy for the correction of adult UPJ obstruction.

Adolescent↗
PubMed2003

Percutaneous nephrolithotomy of an intrathoracic kidney.

We present a 35-year-old woman with symptomatic urolithiasis in an intrathoracic kidney. Percutaneous nephrolithotomy was successfully performed after ureteroscopy failed because of the unusual length of the ureter associated with the kidney position. We report the first case of percutaneous nephrolithotomy of an intrathoracic kidney.

Adult↗
PubMed2002

Hand-assisted laparoscopic nephroureterectomy with cystoscopic en bloc excision of the distal ureter and bladder cuff.

Various hand-assisted and purely laparoscopic nephroureterectomy techniques have been described in the urologic literature. We describe a technique of hand-assisted laparoscopic nephroureterectomy with cystoscopic en bloc excision of the distal ureter and bladder cuff that duplicates open surgical excision of these structures and obviates bladder trocar placement and midprocedural patient repositioning. The patient is placed in a modified dorsal lithotomy position with the tumor side elevated 30 degrees. Allen stirrups are utilized to allow simultaneous access to the urethra. A transperitoneal hand-assisted laparoscopic nephrectomy is performed. The technique is modified in that the ureter is clipped prior to the kidney dissection to avoid distal migration of tumor cells during kidney manipulation. After the kidney is isolated, the intact ureter is liberated distal to the intramural hiatus. The remaining dissection is completed intravesically under cystoscopic guidance. While the surgeon's intra-abdominal hand places the ureter on tension, the cystoscopist transurethrally excises the bladder cuff and intramural ureter with a Collings knife. The complete surgical specimen is removed en bloc through the hand port. The bladder is not closed. A urethral catheter connected to straight drainage remains until the seventh postoperative day, when a cystogram is performed; if it is normal, the catheter is removed.

Carcinoma↗
PubMed2002

Single upper-pole percutaneous access for treatment of > or = 5-cm complex branched staghorn calculi: is shockwave lithotripsy necessary?

BACKGROUND AND PURPOSE: Percutaneous nephrolithotomy for staghorn calculi is reported to have a residual stone rate of 28%, while shockwave lithotripsy alone results in residual stones in approximately 50% of cases. Combination therapy, sandwich therapy, and multiple percutaneous accesses have also been advocated for staghorn stones. We believe these stones can often be removed with a staged procedure via a single upper-pole percutaneous access using flexible nephroscopy and the holmium:YAG laser. Our experience is reviewed. PATIENTS AND METHODS: The hospital records of patients having a cumulative stone burden > or =5 cm who underwent percutaneous nephrolithotripsy (PCNL) for a single complex staghorn calculus were reviewed. There were 15 male and 34 female patients having 45 complete and 7 partial staghorn calculi constituting a mean stone burden of 6.7 cm (range 5.0-10.0 cm). A calix was punctured that would provide access to the majority of the involved calices. Thirty-five renal units were approached through a single upper-pole percutaneous access, and four and six renal units were accessed through single middle or lower-pole calices, respectively. The remaining seven renal units were treated with multiple percutaneous accesses. RESULTS: In the renal units having only a single access, a mean of 1.6 (range 1-3) procedures were required to achieve stone-free status. The mean operating room time was 2.9 hours (range 2.0-3.5 hours). For the second PCNL, the mean operating room time was 63 minutes (range 30-90 minutes). Two patients (two renal units) had residual stones <1 cm in diameter. One refused additional surgery, and the other is awaiting further treatment. The mean estimated blood loss was 238 mL (range 50-800 mL), with only one procedure (2.2%) necessitating a blood transfusion. One (2.8%) hydrothorax developed among the 35 upper-pole puncture cases. Six patients had transient oral temperature readings >101 degrees F with negative blood cultures. Other early complications included single cases of leg cellulitis, atrial fibrillation, and noncardiac chest pain. There were no delayed surgical complications. Patients were discharged from the hospital a mean 2 days (range 1-10 days) after the first PCNL. CONCLUSION: Use of flexible nephroscopy with holmium:YAG laser lithotripsy and Nitinol basket stone extraction has allowed us to render staghorn-containing renal units stone free in a mean of 1.6 procedures. Of the 45 renal units treated through a single percutaneous access, 43 (95%) were rendered stone free. The holmium:YAG laser appears to be a safe lithotrite for the kidney, as no complications occurred from its use.

Adult↗
PubMed2002

Arteriovenous malformation mimicking a renal-cell carcinoma.

We describe a renal arteriovenous malformation in a patient with a 1-month history of flank pain. Imaging studies were interpreted as being consistent with renal-cell carcinoma. However, Doppler ultrasonography demonstrated turbulent blood flow, and selective renal angiography confirmed the diagnosis of an arteriovenous malformation. Embolization relieved the pain. This case calls attention to the need to consider arteriovenous malformations in the differential diagnosis of central homogenously enhancing renal lesions.

Adult↗
PubMedDate not supplied

Laparoscopy-assisted transperitoneal percutaneous nephrolithotomy for renal caliceal diverticular calculi.

BACKGROUND AND PURPOSE: There are a variety of options for the management of symptomatic calculi in caliceal diverticula, each with utility in particular situations. Herein, we describe a laparoscopy-assisted transperitoneal percutaneous nephrolithotomy (PCNL) technique to address the unusual combination of an anterior caliceal diverticulum together with multiple branched calculi having segments both within and proximal to the diverticulum. TECHNIQUE: With the patient in a modified lithotomy position, standard transperitoneal laparoscopy was performed utilizing three 10-mm trocars. After mobilization of the colon medially, the cystic diverticulum was opened. An additional 12-mm trocar was placed to allow transperitoneal PCNL within the diverticulum. Rigid nephroscopy, holmium laser lithotripsy, and stone extraction were performed, including laser enlargement of the diverticular neck and removal of the stone burden proximal to the neck. A double-pigtail ureteral stent and Jackson-Pratt drain were placed. RESULTS: This procedure was successful in the only patient in whom it has been used to date. As far as we know, this is the first report of laparoscopy-assisted transperitoneal PCNL for the management of caliceal diverticular calculi. CONCLUSION: Laparoscopy-assisted transperitoneal PCNL is a safe and effective alternative for the management of symptomatic stones in anterior cystic caliceal diverticula with a narrow neck and complex branched calculi.

Diverticulum↗
PubMedDate not supplied

Laparoscopic pyeloplasty and flexible nephroscopy: simultaneous treatment of ureteropelvic junction obstruction and nephrolithiasis.

BACKGROUND AND OBJECTIVE: Ureteropelvic junction obstruction and concomitant calculus disease may coexist. Therapeutic controversy exists regarding their ideal management. We report our use of flexible nephroscopy during laparoscopic pyeloplasty for caliceal stone removal. METHODS: From August 1998 through May 2002, 50 laparoscopic pyeloplasties were performed. Seven patients had documented ureteropelvic junction obstruction and ipsilateral nephrolithiasis. Preoperative stone burden and location were assessed. After pyelotomy, a 16 Fr flexible endoscope was passed through the uppermost trocar under direct laparoscopic guidance into the collecting system. Stone extraction was performed with a 2.4 Fr Nitinol basket. Postoperative imaging was assessed. RESULTS: Complete stone-free status confirmed by postoperative imaging was achieved in 6 of 7 patients. The longest individual stone diameter ranged from 4 mm to 13 mm (mean, 10.3 mm), and an average of 2.5 stones per patient was removed (range, 1 to 4 stones). Neither intraoperative fluoroscopy nor lithotripsy was required. No intraoperative or delayed complications were noted during a mean follow-up of 8.5 months (range, 2 to 17 months). CONCLUSIONS: Laparoscopic pyeloplasty and concomitant flexible nephroscopy with basket extraction is a simple, attractive alternative for the simultaneous treatment of ureteropelvic junction obstruction presenting with coexisting nephrolithiasis. It appears more efficacious when the stone number is limited and diameters measure from 5 mm to 20 mm.

Adult↗
PubMedDate not supplied

Two trocar laparoscopic varicocelectomy: approach and outcomes.

BACKGROUND AND OBJECTIVES: The surgical indications and proper management of varicoceles in the pediatric population continue to be controversial. Historically, open surgical approaches have had recurrence rates between 2% to 6% and a low rate of complications. We present a modified laparoscopic technique for the treatment of clinically significant varicoceles. METHODS: Consecutive pediatric patients presenting with clinically significant varicoceles between May 2000 and July 2003 were considered for laparoscopic varicocelectomy. A 5-mm 2-port laparoscopic varicocelectomy was performed, with supraumbilical and contralateral lower quadrant placement of the trocars. The Harmonic scalpel was used to fulgurate the spermatic vessels in a nonartery sparing technique. RESULTS: Ten clinically significant varicoceles were identified in 9 patients, all of which were ligated with this technique. One patient was treated for bilateral varicoceles. Average operating room time was 53 minutes (range, 45 to 65). All patients were discharged from the ambulatory surgery unit and returned to their regular physical activity within 2 weeks after surgery. Upon clinical reevaluation 6 weeks post surgery, there was no evidence of varicocele recurrence or hydrocele formation, and all patients were asymptomatic. CONCLUSIONS: Our 2-port laparoscopic varicocelectomy is comparable to traditional open surgical approaches in recurrence and complication rates. This laparoscopic repair may be superior to open techniques in operating time, convalescence, and cosmesis. The procedure is easily mastered and does not require microsurgical skills.

Adolescent↗