Biomedical subjects

Michael Grasso

Publications and source records attributed to Michael Grasso.

5 recordsLinked to original sources

PubMed2006

Advanced ureteroscopy: wireless and sheathless.

BACKGROUND: The introduction of a new generation of flexible ureteroscopes significantly advanced the therapeutic and diagnostic efficacy of the instrument, allowing greater access to all aspects of the upper urinary tract and facilitating wireless ureteroscopy. PATIENTS AND METHODS: Four hundred sixty consecutive upper urinary-tract procedures were performed utilizing the 7.5F actively deflectable, flexible ureteroscope. A prospective database of these procedures was maintained. The indications, access technique, complications, success rate of stone treatment, and access to lower-pole calices were evaluated. The accumulated clinical data were compared with a published database of 1000 consecutive flexible ureteroscopies. RESULTS: A stent was in place or had recently been in place in 108 of the procedures (24%). Of the remaining 352 flexible ureteroscopic procedures, only 11% (52) required any form of ureteral dilation to facilitate ureteral access. Two hundred twenty seven procedures were performed in which no guidewire was required to place the flexible endoscope in the upper urinary tract (i.e., "wireless" ureteroscopy). CONCLUSION: Wireless no-touch flexible ureteroscopy with the new flexible instruments is a feasible and safe technique for diagnostic and therapeutic procedures in most patients, irrespective of the location of the pathology, including the distal ureter. These ureteroscopes, with their exaggerated deflection, are ushering in a new era of endoscopic treatment of the upper urinary tract. Greater instrument deflectability and control can lead to shorter procedures and fewer treatment failures.

Equipment Design↗

PubMed2005

Effect of cystine-binding thiol drugs on urinary cystine capacity in patients with cystinuria.

PURPOSE: To determine the effect of cystine-binding thiol drugs (CBTD) on urinary cystine capacity in patients with cystinuria. PATIENTS AND METHODS: Seven cystinuric patients performed two sets of urine collections while on and off CBTD while controlling for all other variables: diet and fluid and alkali intake. They monitored and recorded their diet for 3 days and performed urine collections on days 2 and 3. They then stopped the CBTD for 7 days. On days 8, 9, and 10, they replicated their diets of days 1 through 3 and performed two more urine collections on days 9 and 10. Two patients took D-penicillamine, four took tiopronin, and one took tiopronin and captopril. The cystine capacity was determined, and the values obtained when the patient was on and off the CBTD were compared to determine whether CBTDs affect urinary cystine capacity. To measure the cystine capacity, we used a solid-phase assay in which cystine crystals are added to the urine and incubated for 48 hours. The crystals are spun down and resolubilized in high-pH buffer, and the amount of cystine in the crystals is calculated. The solid phase will take up cystine from urine (negative cystine capacity) that is supersaturated and give up cystine to an undersaturated urine (positive cystine capacity). RESULTS: All seven patients had significant improvement in urinary cystine capacity on CBTDs. The mean cystine capacity off CBTD was -130.6 +/- 280.8, while the value during CBTD use was 43.1 +/- 131.2 (P < 0.05). On CBTDs, two patients still had negative values, but both had important improvements. The mean urinary volumes were similar on and off CBTD, indicating adequate and similar fluid intake. Urine pH values and urinary excretion of sodium and urea also were comparable, indicating consistency of citrate intake and diet. CONCLUSIONS: Our results demonstrate that CBTDs lower the urinary supersaturation of cystine, as shown by a less-negative or more-positive cystine capacity. Cystine capacity can be measured directly, even in the presence of CBTDs. The value of this measurement lies in the potential to monitor the response to the drug, prescribe the minimum effective dose, and potentially decrease the adverse effects often associated with CBTDs.

Administration, Oral↗

PubMed2005

Ureteroscopic management of upper urinary tract transitional cell carcinoma.

PURPOSE OF REVIEW: Traditionally, nephroureterectomy has been the treatment of choice for transitional cell carcinoma of the upper urinary tract. In an effort to preserve renal function, conservative therapy has evolved from complex open surgery to minimally invasive ureteroscopic therapy. Considering the relatively recent emergence of ureteroscopic therapy, a review of technical considerations and treatment outcome is timely. RECENT FINDINGS: There is emerging evidence that ureteroscopic treatment of low grade upper tract lesions provides an acceptable oncologic result while preserving functioning renal parenchyma. In patients with low grade upper tract urothelial lesions, progression is rarely reported. Ureteroscopy has for over a decade been the premier diagnostic tool, with the actively deflectable flexible instrument being employed to map the entire intrarenal collecting system. Improvements in instrumentation and refinement in technique have broadened the application of the ureteroscope in treating upper urinary tract urothelial tumors. SUMMARY: For low grade lesions, which make up more than 50% of all presentations, ureteroscopic management has proven efficacious. As with similar grade lesions in the bladder, these patients require careful, consistent, and often lifelong follow up as many will develop recurrent lesions throughout the urothelium. Here too, ureteroscopy has a central role in surveillance.

Carcinoma, Transitional Cell↗

PubMed2004

Management of complex biliary tract calculi with a holmium laser.

The difficulty in managing complex biliary tract calculi is exemplified in patients with primary intrahepatic calculi. Standard surgical and endoscopic approaches often fail to clear calculi in these patients who have recurrent episodes of cholangitis. The success of the holmium laser for urologic calculi led us to adapt treatment strategies for primary and secondary biliary tract calculi where standard treatments had been unsuccessful. Our goals were to remove all calculi, prevent recurrent sepsis, and preserve hepatic parenchyma. Thirty-six patients with complex biliary calculi were treated. After sepsis was controlled and the extent of calculi was evaluated, appropriate access to and drainage of the biliary tract was achieved. Holmium laser lithotripsy was performed under video guidance using flexible choledochoscopes and a 200 micro laser fiber generating 0.6 to 1.0 joules at frequencies of 6 to 10 Hz. Lithotripsy procedures were repeated until cholangiography and cholangioscopy confirmed the clearance of calculi. Twenty-two patients of Asian descent with primary intrahepatic calculi and 14 patients with secondary intrahepatic calculi were treated. Access to the biliary tract could be accomplished through percutaneous catheter tracts, T-tube tracts, or the cystic duct during laparoscopic cholecystectomy. Biliary drainage was by biliary enteric anastomosis or endoscopic sphincterotomy. Complete stone clearance required an average of 3.9 procedures (range 1 to 15) for patients with primary intrahepatic calculi and 2.6 procedures (range 1 to 10) for patients with secondary intrahepatic calculi regardless of stone composition. No patient required hepatic resection and no complications or deaths were attributed to the holmium laser. Clearance of calculi can reliably and safely be achieved with a holmium laser regardless of stone composition or location while preserving hepatic parenchyma and preventing recurrent sepsis.

Adult↗

PubMed2004

Pneumothorax in pediatric patients after urological laparoscopic surgery: experience with 4 patients.

PURPOSE: Pneumothorax is a rare but known complication of adult urological laparoscopic surgery and has been described occasionally in children as well. The etiologies for pneumothorax during such procedures are discussed as is the management of pneumothorax in this setting. We investigate the occurrence of pneumothorax during laparoscopic pediatric urological procedures in children. MATERIALS AND METHODS: Pneumothorax developed during urological laparoscopic procedures in 4 pediatric patients (3 females, 1 male). Patient age ranged from 8 months to 11 years (mean 5.4 years). Laparoscopic surgical procedures performed included right upper pole partial nephrectomy, left upper pole partial nephroureterectomy, removal of left multicystic dysplastic kidney and bilateral Cohen reimplantation of ureters. Procedures were performed with a maximum insufflation pressure of 15 mm Hg. During the same time period as these four cases, a total of 285 laparoscopic urologic procedures were performed at our institution. RESULTS: Pneumothorax was suspected due to decreased oxygen saturations, subcutaneous emphysema, increased respiratory effort and decreased chest lung sounds unilaterally. Pneumothorax was confirmed with chest x-rays. Operative time ranged from 171 to 249 minutes (mean 199.5). Duration of surgery before pneumothorax developed ranged from 75 to 239 minutes (mean 176, median 168). Conservative management of pneumothorax was used in 3 patients and a pigtail chest tube was used in 1. In all cases the estimated blood loss was minimal. CONCLUSIONS: Urologists performing laparoscopy in children should be aware of the possibility of a pneumothorax developing during the procedure. Evaluation for decrease in O2 saturation should include a search for pneumothorax in these patients. Close observation generally suffices for management.

Child↗