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Christopher S Ng

Publications and source records attributed to Christopher S Ng.

27 records · Page 2Linked to original sources
PubMed2004

Real-time transrectal ultrasonography during laparoscopic radical prostatectomy.

PURPOSE: We describe the technical aspects of real-time transrectal ultrasound (TRUS) monitoring and guidance during laparoscopic radical prostatectomy (LRP). Furthermore, we describe the TRUS visualized anatomy of periprostatic structures during LRP. MATERIALS AND METHODS: In 25 consecutive patients undergoing transperitoneal LRP, baseline preoperative, real-time intraoperative and immediate postoperative TRUS evaluations were performed. To define periprostatic anatomy precisely TRUS measurements were obtained with specific reference to the neurovascular bundle (NVB), prostate apex, membranous urethra, bladder neck, rectal wall and any cancer nodule. Conventional gray scale, power Doppler, harmonic imaging and 3-dimensional ultrasound functions were used. RESULTS: Real-time TRUS navigation facilitated 3 technical aspects of LRP. 1) It identified the correct plane between the posterior bladder neck and prostate base, allowing quick laparoscopic identification of the vasa and seminal vesicles. 2) It identified the occasional, difficult to see distal protrusion of the prostate apex posterior to the membranous urethra, thus enhancing apical dissection with negative margins. 3) It provided visualization of any hypoechoic nodule abutting the prostate capsule, alerting the laparoscopic surgeon to perform wide dissection at that location. TRUS measured various anatomical parameters including i) the mean distance +/-SD between the NVB and the lateral edge of the prostate a) at apex (1.9 +/- 0.9 mm), b) base (2.5 +/- 0.8 mm) and c) tip of seminal vesicle (4.0 +/- 1.6 mm), ii) the dimensions of the NVB a) before (4.5 x 3.9 mm), b) after (4.2 x 3.6 mm) nerve sparing LRP and c) after nonnerve sparing LRP (0.9 x 0.9 mm), iii) arterial blood flow resistive index within NVB a) before (0.83 +/- 0.04), b) after (0.84 +/- 0.03) nerve sparing LRP and c) after nonnerve sparing LRP (0), iv) and the length of membranous urethra a) before (12.2 +/- 1.1 mm) and b) after (11.7 +/- 1.0 mm) surgery. Focal distortion of the prostate surface by an exophytic nodule was visualized on TRUS in 3 patients, necessitating ipsilateral nerve resection at LRP and contributing to negative surgical margins. CONCLUSIONS: This initial experience suggests that real-time intraoperative TRUS guidance may enhance anatomical performance of LRP. This improved understanding of periprostatic anatomy has the potential to improve functional and oncological outcomes. Such corroboration is awaited.

Humans↗
PubMed2003

Management of failed primary intervention for ureteropelvic junction obstruction: 12-year, single-center experience.

OBJECTIVES: To compare contemporary endourologic and open surgical management of failed primary intervention for ureteropelvic junction obstruction, specifically in regard to immediate and long-term results and complications. METHODS: Since 1989, 48 patients have undergone management of failed primary intervention for ureteropelvic junction obstruction. Of these, 42 patients (21 females and 21 males; age range 16 to 68 years, mean age 34.9) underwent follow-up evaluations. These 42 patients constitute the present study group. The mode of secondary intervention was determined by individual upper tract anatomy, concurrent medical conditions, and informed patient preference. Secondary intervention included open operative repair (n = 20) or percutaneous (n = 11), ureteroscopic (n = 5), or retrograde cautery wire balloon (n = 6) endopyelotomy. Success was defined as symptomatic relief and improved calicectasis on radiographic evaluation at latest follow-up. RESULTS: Follow-up ranged from 6 to 148 months (mean 47.7). Endourologic intervention was associated with a mean hospital stay of 2.3 nights and a complication rate of 13.6%. The long-term success rate of these endoscopic approaches was 59.1% overall, including a 71.4% success rate after a failed open operative procedure and a 37.5% success rate after a failed endourologic procedure. In contrast, open operative salvage was associated with a mean stay of 4.3 nights and a 15% complication rate. The success of open operative salvage was 95% overall, including 94.1% after failed endourologic intervention and 100% after failed open operative intervention. CONCLUSIONS: Endourologic intervention for failed primary management of ureteropelvic junction obstruction is associated with a short hospital stay and low rate of complications. Such intervention provides acceptable success rates in the setting of prior failed open operative intervention. However, when endourologic salvage was used for prior failed endourologic intervention, the success rates were limited. This suggests that intrinsic factors such as crossing vessels or periureteral fibrosis may play a role in limiting the utility of such procedures in this setting. In contrast, open operative salvage after any prior failed intervention for ureteropelvic junction obstruction provides excellent functional results without any increase in morbidity, with, in this contemporary series, an acceptably short hospital stay. These data should help urologists and patients make well-informed treatment decisions.

Adolescent↗
PubMed2003

Metastatic knee.

Explore the source record for details and available documents.

Adenocarcinoma↗
PubMed2002

Impact of renal cryoablation on urine composition.

OBJECTIVES: To examine prospectively serial urine biochemical parameters in 14 patients (9 men, 5 women) undergoing laparoscopic cryoablation of a small, exophytic solid renal mass. Prior studies have shown that various types of renal injury may predispose to the formation of urinary calculi. The metabolic effects of cryoenergy on the surrounding normal renal parenchyma are unknown. METHODS: Timed 24-hour urine collections were obtained preoperatively and postoperatively on days 1, 30, and 60 to evaluate the following parameters: light microscopic findings, volume, pH, creatinine, protein, beta(2)-microglobulin, calcium, citrate, oxalate, phosphate, uric acid, sodium, and potassium. RESULTS: Urinary beta(2)-microglobulin excretion increased from a preoperative baseline value of 114.8 to 1931.2 microg/L on postoperative day 1, an increase of more than 15-fold (P = 0.05), thus confirming major renal injury. These values sharply decreased at 30 days and returned to near-baseline levels at 60 days postoperatively (P = 0.76). Nevertheless, all lithogenic parameters remained within the normal range throughout the follow-up period, with no significant change in any value. CONCLUSIONS: Our findings suggest that renal cryoablation does not adversely alter urine composition with respect to lithogenic parameters for up to 2 months after surgery. Elevated beta(2)-microglobulin levels indicating significant renal injury immediately postoperatively spontaneously revert to baseline levels within 2 months.

Adult↗
PubMed2002

Orthotopic neobladder and subsequent renal transplantation.

Continent urinary diversion has become an attractive alternative to traditional conduits after cystectomy in select patients, including those awaiting renal transplantation. We report a case of a surgically anephric dialysis patient who underwent radical cystoprostatectomy with orthotopic ileal neobladder for recurrent superficial transitional cell carcinoma of the bladder and subsequent living-related renal transplantation 7 months later. We also discuss the perioperative adjuncts paramount to successful outcomes in such patients.

Carcinoma, Transitional Cell↗
PubMed2002

Rhabdomyolysis after laparoscopic donor nephrectomy.

Rhabdomyolysis is a postoperative complication that may result in acute renal failure owing to excessive myoglobinuria. After uncomplicated laparoscopic left transperitoneal donor nephrectomy, a 32-year-old man developed anuric acute renal failure secondary to postoperative rhabdomyolysis that required intermittent hemodialysis for 2 weeks. The presumed risk factors in this case were the patient's high body mass index, intraoperative flank position with flexion, a solitary kidney, and the duration of surgery. Our current surgical technique has been modified to drop the kidney bridge early, immediately after visualization of the hilum.

Acute Kidney Injury↗
PubMed2002

Laparoscopic management of caliceal diverticular calculi.

PURPOSE: We describe laparoscopic techniques for the definitive management of symptomatic caliceal diverticular stone disease. MATERIALS AND METHODS: Five patients underwent retroperitoneoscopic management of a symptomatic, stone bearing caliceal diverticulum. Techniques for intraoperative localization of the stone bearing diverticulum included retrograde injection of indigo carmine, fluoroscopy and/or laparoscopic ultrasound. In 2 cases the patent neck of the diverticulum was sutured via laparoscopy. RESULTS: Complete stone clearance and obliteration of the diverticular cavity was achieved in all cases without any open conversion. Mean operative time was 133.8 minutes. Mean estimated blood loss was less than 50 cc in 4 cases and 150 cc in 1. Mean hospital stay was 36 hours. There were no laparoscopic or postoperative complications. CONCLUSIONS: The laparoscopic approach to symptomatic caliceal diverticula represents an effective and minimally invasive modality for complete clearance of the stone burden and definitive management of the anatomical abnormality. However, patient selection is paramount. We reserve the laparoscopic approach for symptomatic caliceal diverticula with thin overlying renal parenchyma, or for anterior lesions inaccessible to or unsuccessfully managed by endourological techniques. A decision tree algorithm for managing symptomatic caliceal diverticular calculi is proposed.

Adult↗