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Biomedical subjects

Brian R Matlaga

Publications and source records attributed to Brian R Matlaga.

33 records · Page 2Linked to original sources
PubMed2004

Percutaneous CT-guided radiofrequency ablation of renal neoplasms: factors influencing success.

OBJECTIVE: The objective of our study was to evaluate the success rate for radiofrequency ablation of renal tumors and to determine the risk of serious complications. CONCLUSION: No serious complications occurred after 27 CT-guided radiofrequency ablation sessions in 22 patients. In total, no residual tumor was detected on follow-up contrast-enhanced CT or MRI 1-35 months (mean, 7 months) after final tumor ablation in 20 (91%) of 22 patients. Two patients with residual viable tumor deferred further treatment. Complete tumor ablation was achieved after a single treatment session in 83% of patients, and in 8% of patients after subsequent ablation sessions. Size was the major determinant for achieving tumor eradication with a single session of ablation, with all 11 tumors 3 cm or smaller being completely ablated after one session. Tumor location, histology, and the presence of renal disease did not correlate with treatment success. Contrast-enhanced CT performed immediately after ablation is reliable to exclude residual viable tumor. CT-guided radiofrequency ablation of renal tumors is safe and has a high rate of success in the treatment of small renal tumors, with no evidence of recurrence at midterm follow-up of treated patients.

Aged↗
PubMed2003

Prostate biopsy: indications and technique.

PURPOSE: The last decade has seen numerous modifications in the way prostate cancer is diagnosed. We review the current indications for and methods of prostate biopsy. MATERIALS AND METHODS: The English language literature was reviewed regarding major indications for and methods of prostate biopsy. Pertinent peer reviewed articles were collated and analyzed. RESULTS: The most widely accepted indication for prostate biopsy is a prostate specific antigen (PSA) value of greater than 4.0 ng./ml. However, some investigators advocate prostate biopsy for men with a PSA value in the 2.5 to 4.0 ng./ml. range, believing that use of this parameter results in detection of a greater number of cases of curable disease. Age specific PSA range, percent free PSA and presence of prostatic intraepithelial neoplasia or atypia are all considered to be relative indications for prostate biopsy. The current literature describes a trend toward increasing the number of cores obtained and the sites biopsied beyond those of the standard sextant technique. The additional cores in many series are obtained from more lateral regions of the gland. CONCLUSIONS: Although several criteria are used as indications for initial prostate biopsy, all are based on PSA level and/or abnormal digital rectal examination. Future improvements in currently used prostate cancer markers may result in better selection of cases to biopsy. There is no universally accepted technique of prostate gland biopsy. The current literature supports use of more extensive biopsy techniques to increase the likelihood of prostate cancer detection.

Biopsy, Needle↗
PubMed2003

Randomized prospective trial of a novel local anesthetic technique for extensive prostate biopsy.

OBJECTIVES: To determine the effectiveness of a novel technique of administering local anesthesia for extensive prostate biopsy. Little reported experience with local anesthesia for extensive prostate biopsy methods is available. METHODS: A prospective, randomized study was performed on 50 men undergoing transrectal ultrasound-guided prostate biopsy using the five-region technique. Patients were randomized into one of two groups. One group received 22 mL of a 1% lidocaine solution injected into the neurovascular bundles, the genitourinary diaphragm, and between the rectal wall and prostate. The second group received 10 mL of 2% intrarectal lidocaine jelly. A median of 12 biopsy cores was obtained from each patient. The patients were then asked by a urology nurse unaware of the anesthesia method to grade the discomfort using a 10-point linear visual analog pain scale. RESULTS: Twenty-three men received anesthesia with lidocaine jelly, and 27 received anesthesia with lidocaine infiltration. The mean pain scores were significantly different statistically between the lidocaine jelly and lidocaine infiltration groups with respect to overall pain (4.2 versus 0.5) and pain during the biopsy portion of the procedure (4.2 versus 0.5). CONCLUSIONS: Extensive biopsy techniques may be comfortably performed by the urologist in an office setting using local anesthesia. The administration of 22 mL of a 1% lidocaine solution, injected at the prostatic pedicles, the genitourinary diaphragm, and the space between the prostate and rectum, allows the patient to comfortably undergo an extensive biopsy protocol in an office setting.

Administration, Topical↗
PubMed2003

Ileal ureter substitution: a contemporary series.

OBJECTIVES: To review our contemporary experience with ileal ureter reconstruction. Despite advancements in surgical technology and technical expertise, ureteral injuries continue to occur. These injuries can be extensive, and ileal ureter reconstruction may be necessary. METHODS: A total of 18 ileal ureter substitutions were performed in 16 adults (10 men and 6 women) by a single surgeon during a 6-year period. The mean patient age was 49.4 years (range 25 to 72). The mean follow-up was 18.6 months (range 7 to 59). All ileal ureter substitutions were performed in an isoperistaltic, refluxing fashion. Follow-up included clinical evaluation, nuclear renography, intravenous urography, and serum chemistry testing. RESULTS: Postoperative nuclear renography demonstrated no relative loss of function of the affected renal unit and no evidence of functional obstruction. An unobstructed state was also confirmed with intravenous urography. No statistically significant metabolic changes were found in any patient, as assessed by serum chemistry testing. None of the patients had evidence of new stone formation. Two patients developed an isolated, symptomatic urinary tract infection during follow-up, and one has had recurrent urinary tract infections, a problem that was present preoperatively. CONCLUSIONS: Ileal ureter substitution remains an effective treatment for patients with complex ureteral strictures or injuries. Stone activity does not appear to increase, and metabolic sequelae are uncommon in properly selected patients.

Adult↗
PubMed2003

Urologic manifestations of nonurologic disease urolithiasis.

Patients with nephrolithiasis may have coexistent diseases that play a causative role in stone formation. A stone event may be the initial manifestation of the disorder and the urologist may play a major diagnostic role. Regulation or correction of the disorder may eradicate or dramatically attenuate stone activity. In some patients, metabolic abnormalities persist, however, and the therapeutic strategies that were reviewed in this manuscript may need to be implemented. Stone disease may also be induced by drugs that are used to treat a number of disease processes. When this occurs, the drug will usually need to be discontinued and alternative therapy should be instituted.

Acidosis, Renal Tubular↗
PubMed2003

Computerized tomography guided access for percutaneous nephrostolithotomy.

PURPOSE: Access for percutaneous nephrostolithotomy (PNL) using conventional fluoroscopic guidance may carry an increased risk of damage to surrounding organs in patients with renal calculi and aberrant anatomy. In these situations cross-sectional anatomical imaging may facilitate safe percutaneous access. We describe our experience with computerized tomography (CT) guided percutaneous access for such patients undergoing PNL. MATERIALS AND METHODS: Between June 2000 and December 2001, 154 patients underwent PNL at our institution. Five of these patients (3%) required a total of 6 percutaneous access tracks under CT guidance. All patients in this group had anatomical abnormalities precluding standard access to the collecting system without risk to adjacent organs. These abnormalities included a retrorenal colon in 2 and a severely distorted body habitus due to spinal dysraphism in 3. RESULTS: Percutaneous access was achieved without complication in all cases. At subsequent PNL 5 of the 6 renal units (83%) were rendered completely stone-free. CONCLUSION: CT guided percutaneous access is infrequently required for PNL. However, there is a select group of patients with anatomical anomalies that may predictably require this procedure to facilitate safe and efficacious PNL.

Adult↗
PubMed2003

Selecting Treatment for Distal Ureteral Calculi: Shock Wave Lithotripsy versus Ureteroscopy.

Shock wave lithotripsy (SWL) and ureteroscopy (URS) are both effective treatments for removal of distal ureteral calculi, associated with high success rates and limited morbidity. The American Urological Association Ureteral Stones Clinical Guidelines Panel has found both to be acceptable treatment options for patients, based on the stone-free results, morbidity, and retreatment rates for each respective therapy. However, costs and patient satisfaction or preference were not addressed, and the report was based on data derived from older endoscopic and lithotripsy technology. Each of these treatment options has valid advantages and disadvantages. Both modalities are reasonable treatment options for the majority of patients with distal ureteral calculi. Whereas SWL is less invasive, the high, immediate success rate with minimal morbidity and decreased cost makes URS a very valid competitor. The results of treating patients with larger stones favor URS.

Journal Article↗
PubMed2003

Drug-induced urinary calculi.

Urinary calculi may be induced by a number of medications used to treat a variety of conditions. These medications may lead to metabolic abnormalities that facilitate the formation of stones. Drugs that induce metabolic calculi include loop diuretics; carbonic anhydrase inhibitors; and laxatives, when abused. Correcting the metabolic abnormality may eliminate or dramatically attenuate stone activity. Urinary calculi can also be induced by medications when the drugs crystallize and become the primary component of the stones. In this case, urinary supersaturation of the agent may promote formation of the calculi. Drugs that induce calculi via this process include magnesium trisilicate; ciprofloxacin; sulfa medications; triamterene; indinavir; and ephedrine, alone or in combination with guaifenesin. When this situation occurs, discontinuation of the medication is usually necessary.

Journal Article↗
PubMed2002

Phase II trial of radio frequency ablation of renal cancer: evaluation of the kill zone.

PURPOSE: We report on the pathological evaluation of renal tumors after intraoperative radio frequency ablation performed immediately before surgical nephrectomy. MATERIALS AND METHODS: Ten patients with renal tumors were enrolled in a prospective, Institutional Review Board approved phase II trial of radio frequency ablation. Following surgical exposure of the kidney a single 12-minute radio frequency ablation of the tumor was performed using the Radionics Cool-tip RF Radio Frequency Ablation System (Radionics, Burlington, Massachusetts). The tumor was then excised via radical or partial nephrectomy. Gross and histological evaluations of the tumor were performed, including evaluation with nicotinamide adenine dinucleotide vital staining. RESULTS: All 10 tumors were confirmed histologically to be renal cell carcinoma. Mean tumor size was 3.2 cm. (range 1.4 to 8.0). Of the 10 tumors 8 were completely ablated with a mean treatment margin of 6.75 mm. (range 2 to 13). Of the 2 tumors that were incompletely treated 1 never attained a temperature sufficient for tissue destruction and the other measured 8 cm., far exceeding the expected ablation volume of treatment protocol. CONCLUSIONS: This study represents the initial report of the histological outcome of saline cooled radio frequency ablation of renal tumors. Our data indicate that it can completely destroy renal cancers while transmitting minimal collateral damage to surrounding renal parenchyma. Further investigation is required to determine long-term oncological outcome.

Adult↗
PubMed2002

Changing indications of open stone surgery.

OBJECTIVES: To compare the current role of open stone surgery at our institution to previously reported data. In 1989, the indications for open surgical treatment of urinary calculi at our institution were reviewed. In the intervening years, tremendous advances have been made in minimally invasive treatment of urinary calculi. METHODS: A retrospective evaluation of all patients undergoing procedures for the purpose of stone removal or fragmentation at Wake Forest University Baptist Medical Center between January 1, 1998 and May 31, 2001 was conducted. This was compared with data reported from our institution describing similar procedures in the first 19 months after introduction of the Dornier HM3 lithotriptor. RESULTS: Of 986 procedures performed for the purpose of stone removal or fragmentation between January 1, 1998 and May 31, 2001, 0.7% were open surgical procedures. Of these procedures, 85.8% were performed for anatomic indications. Patients referred from other institutions for evaluation after endoscopic treatment failure comprised the remaining 14.2% of this group. In the previously reported data, 893 procedures were performed for the treatment of urinary calculi, of which 4.1% were open operations. Of these patients, 48.6% underwent an open surgical procedure after unsuccessful endoscopic treatment of urinary calculi, and 48.7% of these patients underwent open surgery for anatomic indications. CONCLUSIONS: Open surgical stone removal remains a viable treatment option for select patients. Technologic advances and improved surgical skills have greatly reduced the number of patients requiring open surgery. This approach is mainly used for patients with complex calculous disease associated with anatomic abnormalities.

Adult↗
PubMed2002

Results of the 5 region prostate biopsy method: the repeat biopsy population.

PURPOSE: The decision to repeat prostate biopsy in a patient in whom the first biopsy did not detect prostate cancer poses a challenge to urologists. Many published series show a low yield on repeat biopsy using standard techniques. We reviewed our data on the 5 region prostate biopsy method to evaluate its yield in the repeat biopsy population. MATERIALS AND METHODS: A total of 125 repeat transrectal ultrasound guided prostate needle biopsy sessions were done in 110 patients for standard indications using the 5 region method. Pathological findings were reviewed and the yield of the additional regions was analyzed. RESULTS: Patients were categorized with respect to the initial biopsy technique. In those who underwent 1 and more than 1 previous sextant biopsy the relative increase in yield of the 5 region technique over the standard sextant technique was 31% and 33%, respectively. In the cohort that underwent previous 5 region biopsy the relative increase in yield of the 5 region technique over the standard sextant technique was 38%. CONCLUSIONS: In the setting of repeat biopsy the 5 region method results in an increased yield over the sextant method. It is true in patients who have previously undergone biopsies with the sextant or 5 region technique.

Aged↗
PubMed2002

The treatment of lower pole renal calculi in 2003.

The optimal treatment of patients with lower pole renal calculi is still being defined. Shock wave lithotripsy, percutaneous nephrolithotomy, and ureteroscopy are all currently utilized to treat patients with this condition. These methods have yielded varying degrees of success. The influence of collecting system anatomy on shock wave lithotripsy results remains controversial. Ongoing randomized, prospective trials evaluating the efficacy of all of these respective therapeutic options will, it is hoped, determine the best approaches for this patient cohort.

Journal Article↗