Neodymium:YAG laser coagulation prostatectomy: 3 years of experience with 227 patients.

PURPOSE: For 3 years we prospectively followed a cumulative cohort of men who underwent neodymium:YAG laser coagulation prostatectomy to relieve bladder outlet obstruction to determine the safety, efficacy and durability of this procedure. MATERIALS AND METHODS: A total of 227 men with symptomatic bladder outlet obstruction was treated with the Urolase side-firing laser fiber between October 15, 1991 and October 15, 1994. Voiding outcomes, including peak urinary flow rates, residual urine volumes and American Urological Association symptom scores, were measured with time, and immediate and long-term complications were assessed. RESULTS: Median patient followup was 26 months (maximum 42). Significant improvement occurred in all measured voiding parameters, including 133% in peak flow rates and 61% in symptom scores 1 year postoperatively. Overall 87% of patients noticed improved quality of life as a result of surgery. Minimum postoperative followup was 6 months in all cases. Complications included prostatitis in 2.6% of patients, urethral stricture in 1.8%, bladder neck contracture in 4.4% and reoperation for residual prostate tissue in 5.3%. CONCLUSIONS: Neodymium:YAG laser coagulation of the prostate represents an efficacious surgical intervention for symptomatic bladder outlet obstruction with minimal associated morbidity. Voiding outcomes are durable through 3 years.

Laser prostatectomy performed with a right-angle firing neodymium:YAG laser fiber at 60 watts power setting.

A total of 50 patients with symptomatic bladder outlet obstruction due to benign prostatic hyperplasia was entered into a prospective trial of laser prostatectomy performed with the right-angle firing neodymium:YAG laser fiber at 60 watts power setting. Mean estimated resectable prostatic weight was 30 gm. with a mean prostatic urethral length of 3.3 cm. Nine patients (18%) were in urinary retention requiring catheterization before treatment. Mean energy delivery was 30,834 joules (range 14,400 to 127,800) with a mean operative time of 31 minutes. Efficacy of treatment was assessed at 3, 6 and 12 months postoperatively by standardized American Urological Association symptom scores, peak urinary flow rates and post-void residual urine volumes. At preoperative baseline the mean symptom score was 20.8, mean peak urinary flow rate 7.6 cc per second, and mean post-void residual urine volume 353 cc. At 1 year postoperatively mean symptom score was 8.4, mean peak urinary flow rate was 18.7 cc per second and mean post-void residual urine volume was 175 cc. Two patients required retreatment for residual tissue. There were 6 complications including 5 bladder neck contractures requiring incision (10%) and 1 case of postoperative prostatitis requiring antibiotic therapy (2%). Of 37 evaluable sexually active patients 31 (84%) reported preservation of antegrade ejaculation postoperatively.

Neodymium: yttrium-aluminum-garnet laser dosimetry for the prolase II side-firing delivery system in the human prostate.

OBJECTIVES: The objective of this study was to define optimal treatment parameters and quantitative dosimetry for neodymium:yttrium-aluminum-garnet (Nd:YAG) laser coagulation prostatectomy utilizing the ProLase II side-firing laser delivery system. METHODS: Transurethral Nd:YAG laser application was performed with the ProLase II side-firing laser fiber in adult human prostates prior to planned radical prostatectomy. Depth and volume of prostatic tissue coagulation for single, continuous laser applications were measured at variable power settings from 40 to 80 W, while holding total energy delivery constant. Holding the power setting constant, the extent of tissue coagulation was similarly measured for variable treatment times from 45 to 90 seconds. RESULTS: Peak tissue coagulation for the ProLase II was observed at 60 W--up to a maximum of 13 mm tissue penetration and 3.92 cc volume coagulation following a single spot laser application. The mean depth of tissue coagulation at 60 W power setting was 12.7 mm, with a mean volume of tissue coagulation of 3.07 cc. Holding the power setting constant at 60 W, and increasing treatment time from 45 to 60 seconds, the extent to tissue coagulation increased significantly. However, beyond 60 seconds continuous laser application at 60 W, a plateau in tissue effects was observed, with minimal increase in tissue coagulation between 60 and 90 seconds. CONCLUSIONS: Using the ProLase II side-firing laser fiber, 60-second Nd:YAG spot laser applications at 60 W power setting represent optimal treatment parameters. The quantitative dosimetry curves produced for the ProLase II fiber are compared with prior dosimetry studies with the Urolase delivery system.

Comparative study of laser versus electrocautery prostatic resection: 18-month followup with complex urodynamic assessment.

A total of 25 patients with symptomatic bladder outlet obstruction due to benign prostatic hyperplasia was entered into a prospective, randomized trial comparing prostatectomy done with the Urolase right angle firing neodymium:YAG laser fiber and standard transurethral electroresection of the prostate. Efficacy of treatment, as assessed by standardized American Urological Association symptom scores, patient assessment of symptom improvement, peak urinary flow rates, post-void residual urine volumes and complex urodynamic evaluation, including assessment of opening pressure and maximum detrusor voiding pressure, was equivalent for the 2 treatment groups through 1 year. Ultrasonic assessment of prostatic volumes at 1 year showed a mean decrease in total volume of 59% for standard electrocautery resection compared to 28% for laser prostatectomy. Symptom scores and peak urinary flow rates remained equivalent for both groups through 18 months.

Mediastinal lymph node evaluation by computed tomography in lung cancer. An analysis of 345 patients grouped by TNM staging, tumor size, and tumor location.

To more clearly characterize the role of computed tomography in staging the mediastinal lymph nodes of patients with lung cancer, we analyzed computed tomographic and surgical findings in the chest in 345 consecutive patients with lung cancer who underwent operative staging. Patients were grouped according to the TNM staging system of the American Joint Commission, central or peripheral location of the primary tumor, lobar location of the tumor, and maximum tumor diameter as determined by computed tomography or gross pathology. One third of patients with abnormal findings on the computed tomographic scan did not have mediastinal lymph node metastases. Mediastinal metastases occurred frequently in patients with central cancers (38%). The predictive value of a negative scan in all patients was high (greater than or equal to 90%) except for patients with central T3 lesions (72%), left upper lobe lesions (83%), and central adenocarcinomas (75%). However, only the differences between central T3 and central T2 or T1 lesions, and between central adenocarcinomas and central squamous cell carcinomas, were unlikely to be due to chance alone (p less than 0.05). None of the lobar differences were statistically significant. The frequency of mediastinal metastases in patients with peripheral lesions was 15% (28 of 192 patients); computed tomography correctly identified enlarged mediastinal lymph nodes in all but seven patients. However, there were no true-positive computed tomographic scans in 59 patients with peripheral lesions 2 cm in diameter or smaller; accordingly, we suggest that computed tomography is not indicated for the sole purpose of mediastinal staging in this group. Ninety-four percent of patients in this series undergoing thoracotomy with a curative intent had a curative resection. Only 4% had unresectable lesions; palliative resections were done in 2%.

Computed tomography. An effective technique for mediastinal staging in lung cancer.

Computed tomographic scans of the chest were utilized to stage mediastinal disease in 148 instances of bronchogenic carcinoma considered for resection in 146 patients. Nodes greater than or equal to 1.5 cm in diameter were interpreted as abnormal. All nodes positive by computed tomography were evaluated by mediastinoscopy, anterior mediastinotomy, or thoracotomy. All patients with negative computed tomographic findings underwent thoracotomy without prior surgical staging. Patients undergoing thoracotomy were divided into two groups. In Group I (first 51 instances) routine mediastinal exploration was not carried out; in Group II (last 97 instances) the mediastinum was explored in every patient and nodes were submitted for histopathological study. The computed tomographic and pathological findings on the mediastinal lymph nodes were compared. The sensitivity, specificity, and accuracy of computed tomography in Group I were 88%, 94%, and 92%, respectively, in Group II 75%, 89%, and 86%, and in the combined group, 80%, 91%, and 88%. The positive predictive index in Group I, Group II, and in the combined group was 88%, 69%, and 77%, respectively. It was lower for central than peripheral lesions (74% versus 88%) and was lowest for lesions in the right upper and left lower lobes. The negative predictive index was greater than 90% for all groups and all tumor sites except the left upper lobe, where it was 89%. Ten patients had false-positive scans, three with old mediastinitis and seven with postobstructive pneumonia; nine of the 10 had central lesions, and seven of these lesions were located in the right upper lobe. Eight patients had false-negative scans; six had para-aortic, subaortic, or postsubcarinal nodes. These nodes would not have been accessible to mediastinoscopy. In only one patient with false-negative nodes would routine mediastinoscopy have prevented thoracotomy and resection. Computed tomographic staging of mediastinal disease is indicated for all patients with lung cancer in whom operation is contemplated. Computed tomography directs the most appropriate staging procedure for patients with positive findings and obviates invasive staging for patients with negative findings.