Biomedical subjects

David M Albala

Publications and source records attributed to David M Albala.

43 records · Page 3Linked to original sources

PubMed2002

Urinary calculi in aviation pilots: what is the best therapeutic approach?

PURPOSE: We reviewed treatment outcomes in a series of aviation pilots treated in the era of modern surgical techniques and provide recommendations regarding treatment in this unique group. MATERIALS AND METHODS: We retrospectively analyzed the records of all aviation pilots surgically treated for urinary calculi at our 4 tertiary stone centers from January 1988 to June 2000. Preoperative data and postoperative results were evaluated. Primary outcome measures included stone-free status after initial therapy, time lost from work and overall stone-free rates. Secondary outcome measures included the need for secondary procedures and complications. RESULTS: Of the 36 patients 17 had renal and 19 had ureteral stones. In 4 patients the stones passed spontaneously, while 17 were initially treated with extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Marietta, Georgia), 9 were initially treated with ureteroscopy and 6 were treated with percutaneous nephrolithotripsy. There was 1 complication. The stone-free rate for ESWL, percutaneous nephrolithotripsy and ureteroscopy after initial therapy was 35%, 100% and 100%, respectively. All patients were rendered stone-free after secondary therapy. Mean time lost from work for ESWL, percutaneous nephrolithotripsy and ureteroscopy was 4.7, 2.6 and 1.6 weeks, respectively. CONCLUSIONS: Aviation pilots with surgical urolithiasis are best treated with an initial endoscopic procedure. Stone-free rates can be maximized, while time lost from work can be minimized when an endoscopic approach is used initially. All pilots with urolithiasis should undergo mandatory metabolic evaluations to institute medical therapy when indicated.

Adult↗

PubMed2002

Techniques to maximize flexible ureteroscope longevity.

OBJECTIVES: To assess methods to improve the longevity and durability of flexible ureteroscopes by using the ureteral access sheath, 200-microm holmium laser fiber, and nitinol baskets or graspers during routine ureteroscopic procedures. Despite adequate advances in fiberoptics and endoscope design, the decreased size of currently available flexible ureteroscopes makes damage inevitable after repeated use. However, new auxiliary tools may be able to enhance ureteroscope durability. METHODS: The indications for performing flexible ureteroscopy were proximal ureteral stones (n = 32), renal calculi (n = 59), treatment of upper tract transitional cell carcinoma (n = 3), evaluation of hematuria or filling defect (n = 7), and treatment of ureteral strictures or ureteropelvic junction obstruction (n = 8). Using four new 7.5F flexible ureteroscopes, we prospectively evaluated the number of passes of each ureteroscope until more than 20 optical fibers were broken, more than a 25 degrees loss of deflection in either direction had occurred, or the instrument sustained injury requiring repair by the manufacturer. RESULTS: One hundred nine flexible ureteroscopic procedures (average 27.5 procedures per instrument; range 19 to 34) were performed with the four new flexible ureteroscopes before being sent for repair. Adjuncts to reduce scope damage during these procedures were the use of the ureteral access sheath (n = 109), nitinol devices allowing lower pole stone retrieval (n = 27), and the 200-microm holmium laser fiber for stone fragmentation, tumor ablation, and incision of ureteropelvic junction/ureteral stenoses (n = 91). The average number of passes until more than 20 optical fibers were broken was 15.3 (range 12 to 20), until more than a 25 degrees loss of deflection occurred was 50.3 (range 42 to 66), or until the scope required repair was 66.7 (range 46 to 82). CONCLUSIONS: Flexible ureteroscopy will be used increasingly to manage upper urinary tract pathologic findings. Historically, the number of procedures performed before a flexible ureteroscope requires repair averaged 6 to 15. By incorporating the new ureteroscopic accessories, such as nitinol devices, a ureteral access sheath, and the 200-microm holmium laser fiber into common practice, one can reduce the strain on these fragile 7.5F endoscopes, thereby maximizing their longevity.

Equipment Failure↗

PubMed2002

Office-based transurethral microwave thermotherapy using the TherMatrx TMx-2000.

BACKGROUND AND PURPOSE: Transurethral microwave thermotherapy (TUMT) is an effective therapy for symptomatic benign prostatic hyperplasia (BPH), but the trade-off between the magnitude of clinical improvement and side effects and patient tolerance has limited its appeal to patients and urologists. This study, using the TherMatrx TMx-2000, a TUMT device that directly heats the transition zone to greater than 50 degrees C, has been focused on resolving these issues and developing a truly office-based therapy that is well tolerated with a benign post-treatment course. PATIENTS AND METHODS: This study was multi-institutional and designed as a blinded, randomized, and sham-controlled trial. A series of 200 patients with an AUA Symptom Index (AUASI) of >12, a peak flow rate of <12 mL/sec, and cystoscopic evidence of BPH were randomized 2:1 (active to sham) and treated in seven physician offices under a Food and Drug Administration-supervised and audited premarket approval protocol. No intravenous sedation was used in any patient. Follow-up for the sham-treatment group was 3 months, at which time, patients could cross over to an active treatment. A total of 119 patients have completed 1-year follow-up. RESULTS: The active and sham groups were statistically identical at baseline. The 1-hour total treatment was extremely well tolerated using urethral lidocaine and oral medications; not a single prostate block or parental dose of medication was required. The active-treatment group demonstrated a statistically significant reduction (p < 0.05) in AUASI at 3 months compared with sham treatment, with an AUASI decrease from 22.4 to 12.4 (n = 124) for active v 22.9 to 17 for sham (n = 62). For the 119 patients in the active arm who have reached 12 months, the AUASI has fallen to 10.6 points (47.1% decrease), and the peak flow rate has increased 5.0 mL/sec (58.1%). Postprocedure catheterization was typically 2 or 3 days, and the 16.8% of patients who failed their first voiding trial all voided within 1 week. No major adverse events such as stricture, rectal findings, or ejaculatory changes have been reported. CONCLUSIONS: This study demonstrates that the TherMatrx TMx-2000 TUMT effectively treats symptomatic BPH in the physician office with minimal morbidity.

Aged↗

PubMed2002

Hand-assisted urological laparoscopy.

Hand-assisted laparoscopy has been successfully applied to various applications within the field of urology. Many authors have proved the safety and efficacy of this technique, as well as demonstrating improved patient recovery for such procedures as radical nephrectomy, radical nephroureterectomy and donor nephrectomy. The recent literature regarding this topic is reviewed and evaluated here.

Equipment Design↗

PubMed2002

Acute and long-term outcomes of radio frequency bladder neck suspension.

PURPOSE: A new treatment modality for women with stress urinary incontinence secondary to urethral hypermobility is radio frequency bladder neck suspension. Radio frequency energy is a form of electromagnetic energy that is reliable and highly controllable. This thermal therapy can produce well-defined areas of tissue heating. The technology has been used extensively in dermatological and orthopedic surgery for tissue shrinkage and ablation. Radio frequency thermal therapy is now being applied to the endopelvic fascia at the bladder neck and urethra for treating hypermobility in patients with stress urinary incontinence. The purported mechanism is shrinkage of the collagenated tissue that supports the bladder neck and proximal urethra. We report our acute and long-term experience with laparoscopic radio frequency bladder neck suspension for stress urinary incontinence. MATERIALS AND METHODS: Enrolled in this prospective multicenter trial were 94 women with a mean age of 48.4 +/- 7.6 years who had urethral hypermobility with an average cotton swab angle change of 41 degrees and Valsalva leak point pressures greater than 90 cm. water at 250 ml. bladder capacity. Detrusor instability was excluded by cystometry. In all cases precisely controlled radio frequency energy was applied to the endopelvic fascia to heat and shrink the tissue. The primary end points were physician assessment of continence, patient reported pad use and the number of patient reported episodes of urinary incontinence daily 1, 3, 6 and 12 months after surgery. RESULTS: Average operative time was less than 60 minutes and 98% of the patients were discharged home from the recovery room. Treatment surface area decreased an average of 17% in length and 21% in width. Preoperatively 78% of patients had an average of 1 or more episodes of urinary incontinence daily. At 1, 3, 6 and 12 months there was an average of 1 or fewer episodes of urinary incontinence daily in 84.7%, 85.6%, 85.9% and 77.4% of patients, respectively, and at 12 months 83.5% reported being continent or improved. Preoperatively 41.2% of patients reported using 1 pad or less daily, while at 1, 3, 6 and 12 months 85.6%, 90.4%, 87.2% and 86.9%, respectively, required 1 pad or less daily. Urodynamic evaluation at 12 months showed no leakage during the Valsalva maneuver in 78% of cases. There were no major postoperative complications and the minor complication rate was 5.3%. CONCLUSIONS: Early results of thermal treatment of the endopelvic fascia indicate that radio frequency bladder neck suspension is safe and effective for improving stress urinary incontinence in women. The improvement in symptomatology appears to be durable in most patients at the 1-year followup. Longer followup is needed to assess the durability of results and it is currently in progress.

Catheter Ablation↗

PubMed2002

Routine postoperative imaging is important after ureteroscopic stone manipulation.

PURPOSE: Improved fiber optics and advanced intracorporeal lithotripsy devices have significantly decreased the incidence of complications during ureteroscopic procedures. Despite recent reports suggesting that radiographic imaging may not be necessary in all individuals after routine ureteroscopy silent obstruction may develop in some, ultimately resulting in renal damage. We determined the incidence of postoperative silent obstruction at our institution and assessed the need for routine functional radiographic studies after ureteroscopy. MATERIALS AND METHODS: We retrospectively reviewed the charts of 320 patients who underwent a total of 459 ureteroscopic procedures for renal or ureteral calculi in a 3-year period. Complete followup with imaging was available for 241 patients (75%). Average patient age was 47.2 years. The variables of interest reviewed included preoperative pain, preoperative obstruction, targeted calculous site, stone-free rate, postoperative pain and postoperative obstruction. Mean followup was 5.4 months (range 2 to 43). RESULTS: A total of 241 patients with complete followup were identified in this analysis. Preoperative pain was present in 202 patients (84%) and 168 (70%) had preoperative obstruction. Overall targeted calculous clearance was successful in 73% of the patients and an additional 15.8% had residual fragments less than 4 mm. The renal, proximal or mid and distal ureteral stone-free rate was 32.1%, 81.9% and 90.5%, while in an additional 46.4%, 6.3% and 6.7% of cases, respectively, residual fragments were less than 4 mm. Of the 241 patients 30 (12.3%) had obstruction postoperatively due to residual stone in 25 (83.3%), stricture in 3 (10%), edema of the ureteral orifice in 1 (3.3%) and a retained encrusted stent in 1 (3.3%). Postoperatively obstruction correlated with postoperative pain in 23 of the 30 patients (76.7%). Pain was present postoperatively in 30 of the 211 patients (14%) without evidence of ureteral obstruction postoperatively. However, silent obstruction developed in 7 patients (23.3%) or 2.9% of the total cohort. All 7 patients underwent secondary ureteroscopy to alleviate obstruction. A single patient ultimately received chronic hemodialysis for renal failure, 1 was lost to followup and in 5 there was documented successful resolution of the cause of obstruction. CONCLUSIONS: Our analysis suggests that silent obstruction remains a potentially significant complication after stone management. Relying on postoperative pain to determine the necessity of postoperative imaging places patients at risk for progressive renal failure due to unrecognized obstruction. Therefore, we recommend that imaging of the collecting system should be performed by excretory urography, spiral computerized tomography or ultrasound within 3 months after routine ureteroscopic stone treatment to avoid the potential complications of unrecognized ureteral obstruction.

Adult↗

PubMedDate not supplied

PlasmaKinetic bipolar vessel sealing: burst pressures and thermal spread in an animal model.

BACKGROUND AND PURPOSE: Laparoscopic bipolar instruments are commonly employed to cauterize and divide tissue. A next-generation bipolar device has been developed that employs vapor pulse coagulation energy. We assessed the vessel-sealing capability of this device and quantified thermal spread during application. MATERIALS AND METHODS: Bilateral laparoscopic nephrectomy was performed on six common swine >25 kg. Five-millimeter clips and surgical staplers (US Surgical, Norwalk, CT) were utilized to perform nephrectomy on one side, while the Gyrus PlasmaKinetic bipolar device (Minneapolis, MN) was employed for the contralateral nephrectomy. Vessel-sealing capabilities were assessed via burst-pressure studies. The extent of thermal spread was measured after tissue fixation and hematoxylin and eosin staining. RESULTS: Surgical clips/vascular staplers adequately controlled/sealed renal hilar vessels with burst pressures nearing 300 mm Hg. The Gyrus bipolar device reliably sealed and divided renal arteries <or=5 mm with burst pressures averaging 291 mm Hg. Renal arteries above this size were not consistently sealed, but, with the exception of one technical error, renal veins of all sizes (3-12 mm) were reliably controlled (average burst pressure 288 mm Hg). Histologic evidence of thermal spread extended an average of 3.6 mm from the cut edges of arteries and 3.4 mm from the edges of veins. CONCLUSIONS: The Gyrus PlasmaKinetic bipolar device is capable of reliably sealing/ dividing arteries as large as 6 mm, although we recommend restricting its use to vessels no larger than 5 mm in diameter to allow a safety margin. In addition, porcine renal veins of all sizes are adequately controlled. These sealed vessels are able to withstand pressures approaching 300 mm Hg. Thermal spread affects only the area surrounding the divided vessel. Further clinical studies are warranted.

Animals↗