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Biomedical subjects

Louis Eichel

Publications and source records attributed to Louis Eichel.

28 records · Page 2Linked to original sources

Comparison of the Ti-knot device and Hem-o-lok clips with other devices commonly used for laparoscopic renal-artery ligation.

BACKGROUND AND PURPOSE: New devices such as the Ti-knot and Hem-o-lok clips have been developed for laparoscopic surgical applications. We compared the effectiveness of Ti-knot TK5 (LSI Solutions), Hem-o-lok MLK clips (Weck Closure), Ligaclip 5-mm titanium clips (Ethicon), and Endopath vascular staples (35 mm long, 12.3 mm wide) (Ethicon). MATERIALS AND METHODS: Renal artery segments from 5 to 6 mm in diameter were harvested from fresh porcine kidneys. One end of the vessel was intubated with a 25-gauge ball-tipped needle and fastened with two silk ties. The other end was occluded with one of the test devices. Saline was infused into each arterial segment at 3 mL/min with the maximum pump pressure at 800 mm Hg. The maximum pressure with leakage was recorded. Each of the five test devices was tested eight times on a rotating basis. Saline infusion was stopped when the maximum pump pressure was reached or when leakage was observed. RESULTS: All Ti-knot devices, Hem-o-lok clips, titanium metal clips, and standard hand ties tolerated pressures >800 mm Hg with no leakage, but 4 of the 8 vascular staple lines (50%) leaked before this maximum pump pressure was reached. For those that leaked, the mean leak pressure was 273 mm Hg (range 237-322 mm Hg). CONCLUSIONS: All devices tested are capable of occluding renal arteries under physiologic conditions. Ti-knot devices and Hem-o-lok clips occluded renal arteries to pressures that exceeded 800 mm Hg. They are equivalent to hand ties under supraphysiologic conditions.

Animals↗

One-knot pyeloplasty.

Laparoscopic pyeloplasty represents one of the more advanced reconstructive procedures for the urologist. While early reports were replete with long operative times, there have been several changes that have added to the efficiency of the procedure. In our practice, we have found three changes to be of greatest value: (1) an upper-midline port placement; (2) use of a continuous suture for the anastomosis with a double-armed, knotted suture; and (3) antegrade stent placement.

Humans↗

Sealing percutaneous nephrolithotomy tracts with gelatin matrix hemostatic sealant: initial clinical use.

PURPOSE: Tubeless percutaneous nephrolithotomy (PCNL) has been performed at several centers with good success. However, these cases have been carefully selected with regard to short duration and smaller stone burden to prevent complications associated with the loss of access to the collecting system. We describe the use of gelatin matrix hemostatic sealant (FloSeal Baxter Medical, Fremont, California) as an adjunct to tubeless percutaneous nephrolithotomy to help preclude bleeding complications. MATERIALS AND METHODS: Two patients were treated with PCNL through a single nephrostomy tract. At the satisfactory conclusion of the cases the tract was occluded retrograde with an occlusion balloon catheter and gelatin matrix hemostatic sealant was injected down the nephrostomy tract. An indwelling stent and bladder catheter were placed following which all guidewires were removed and skin sutures were placed. RESULTS: The operative times were 75 and 180 minutes, respectively. Both patients had stable postoperative hemoglobin and no evidence of bleeding or obstruction on postoperative computerized tomography. CONCLUSIONS: Injection of gelatin matrix hemostatic sealant into the nephrostomy tract may be of value in preventing bleeding after PCNL. In this pilot experience it provided immediate and effective hemostasis.

Female↗

Comparison of guide wires in urology. Which, when and why?

PURPOSE: We compared and contrasted various guide wires with regard to their physical properties as they apply to their use for the access or coaxial passage of other catheters. MATERIALS AND METHODS: Certain 0.035-inch diameter guide wires were tested with regard to tip bending force, shaft bending force, pull force and tip puncture force, namely the Roadrunner PC and polytetrafluoroethylene (PTFE) wire guide (Cook Urological, Spencer, Indiana), Glidewire, Bentson type 15 cm flexible tip PTFE coated guide wire and Amplatz super stiff Urowire XF (Boston Scientific Microvasive, Miami, Florida), Bentson guide wire and Amplatz guide wire (Applied Medical, Rancho Santa Margarita, California) and the PTFE coated Bard guide wire (Bard Urological Division, Covington, Georgia). RESULTS: Regarding guide wires used for access, the Boston Scientific PTFE guide wire with a 15 cm flexible tip required the least amount of force to deflect the tip. Of the 3 cm flexible tip guide wires the Applied Bentson guide wire had the most flexible tip and the Bard guide wire had the stiffest flexible tip. The Boston Scientific Glidewire required the least amount of force to pull from a tortuous pathway and this guide wire also required the greatest force (4 times as much force as the other guide wires) to puncture the aluminum foil (p < 0.001), indicating the safety of its tip. Regarding axial rigidity for the coaxial passage of other catheters over a guide wire, the Boston Scientific Amplatz super stiff guide wire was significantly more resistant to bending than all of the other guide wires that we tested (p < 0.05). CONCLUSIONS: Brand name guide wires designed for the same purpose appear to differ markedly with regard to flexibility, lubricity and shaft stiffness. In general, floppy tip and nitinol based guide wires appear to be best used for access with an emphasis on tip flexibility and a low friction coating, while the stiffer shaft guide wires are selected for coaxial passage of catheters, stents and sheaths.

Equipment Design↗

Continuous bladder infusion methods for studying voiding function in the ambulatory mouse.

OBJECTIVES: To develop a method for chronic cannulation of the mouse bladder that would enable repeated intravesical drug delivery and measurement of voiding patterns in unrestrained mice under controlled infusion conditions. METHODS: Fifteen female mice were anesthetized with halothane and implanted with a 3F polyurethane bladder catheter. The catheter exited from the back through mesh and a polysulfone button into a spring coil that protected the catheter and tethered the mouse. A counterbalanced swivel and infusion pump permitted unencumbered mobility during continuous intravesical perfusion. RESULTS: Patent catheterization was consistently achieved for at least 5 weeks. The voiding patterns produced with an infusion pump were stable not only within a study session but also during the course of several weeks. The catheters remained patent but eventually withdrew from the bladder in 9 mice, at which point the mice were killed. The mesh eventually emerged from the skin in 4 animals without evidence of infection and was associated with catheter leakage at the level of mesh exposure. The subcutaneous placement of the mesh and tether assembly adequately transferred torque to the swivel without catheter obstruction. One mouse died unexpectedly during anesthesia; another was killed 1 week after catheter implantation because of an intraperitoneal leak. No bladder stones were identified. The results of the urine cultures were inconclusive. CONCLUSIONS: Continuous, patent catheterization of the murine bladder can be achieved consistently for a period of 5 weeks. When used in combination with counterbalanced swivel assemblies and electronic balance technology, these methods permit prolonged evaluation of micturition patterns in the awake, ambulatory mouse.

Administration, Intravesical↗

Current trends in urologic laparoscopic surgery.

PURPOSE: We examined the status of laparoscopy in urology and the impact of residency and fellowship training on the performance of laparoscopy as primary surgeon. We also examined whether performing nonsurgical tasks requiring two-handed dexterity had any link to the adoption of laparoscopic techniques by urologists. MATERIALS AND METHODS: A total of 8760 laparoscopy questionnaires containing 135 queries were mailed to urologists listed on the American Urological Association practicing urologists mailing list. The questions sought information on area of practice, time in practice, fellowship training, ambidexterity, laparoscopic experience, and experience with robotics. The response rate was 1.8% (155 of 8760). RESULTS: There appeared to be no significant correlation between the performance of laparoscopic surgery and participation in activities requiring bimanual dexterity. However, a correlation of strong statistical significance did exist between laparoscopic residency training and performance of laparoscopy after residency (p=0.003. There also was a correlation between fellowship training in laparoscopy/endourology and doing laparoscopy as primary surgeon. CONCLUSIONS: Participation in laparoscopic surgery during residency training is a major determining factor in performance of laparoscopy as a primary surgeon in practice. Younger surgeons trained in laparoscopy during residency are performing more laparoscopy post residency than those without laparoscopic training during residency. At present, there is a need to train more urologists in laparoscopy at the postgraduate level.

Adult↗

Tubeless percutaneous nephrolithotomy using hemostatic gelatin matrix.

We describe using hemostatic gelatin matrix (FloSeal; Baxter Inc., Irvine, CA) to provide hemostasis of the tract after percutaneous nephrolithotomy, thereby obviating a nephrostomy tube. For patients who are rendered stone free, a 7F, 11.5-mm occlusion balloon catheter, passed retrograde, is used to occlude the collecting system at the level of entry of the 30F Amplatz sheath. FloSeal is then injected through the partially retracted Amplatz sheath while withdrawing the applicator and the sheath in tandem. The guidewire is withdrawn per urethra until its tip resides in the renal pelvis. A 36-cm, 7F tail stent is passed retrograde, and the skin is closed with cyanoacrylate adhesive (Ethicon, Somerville, NJ). A Foley catheter is placed, to be removed the next morning; the patient can be discharged on postoperative day 1. The ureteral stent is removed in 5 to 7 days as an outpatient procedure.

Balloon Occlusion↗

Rapid communication: early potency outcomes with cautery-free neurovascular bundle preservation with robotic laparoscopic radical prostatectomy.

PURPOSE: To report short-term potency outcomes with a cautery-free technique (CFT) to preserve the neurovascular bundles (NVB) during robotic laparoscopic radical prostatectomy (LRP). PATIENTS AND METHODS: All men were <66 years of age and had a Sexual Health Inventory in Men (SHIM) score of 22 to 25. They underwent unilateral or bilateral dissections. Group 1 (N = 23), the study group, had preservation of the NVB with CFT. Group 2 (N = 36) had traditional dissection using bipolar cautery. Data were collected prospectively via validated questionnaires. Potency was defined as an erection adequate for vaginal penetration. RESULTS: At 3 months, 10 patients (43%) in the CFT group reported potency versus just 3 (8.3%) in the bipolar-cautery group (P = 0.003). Additionally, only 2 (18%) of those having CFT reported zero penile fullness compared with 15 (68%) in the bipolar-cautery group (P = 0.01). CONCLUSIONS: The technique of controlling the vascular pedicle of the prostate and dissecting the NVB without cautery produced significant improvement in potency outcomes at just 3 months.

Adult↗

Ureteral pseudodiverticulum associated with absorbable suture clips after laparoscopic pyeloplasty: case report.

A 48 year-old woman with pyelonephritis was found to have bilateral ureteropelvic junction (UPJ) obstruction and a nonfunctioning right kidney. She initially underwent a laparoscopic left nondismembered pyeloplasty using absorbable polydioxanone Lapra-Ty suture clips (Ethicon Endosurgery, Cincinnati, OH) to secure the anastomosis. An antegrade endopyelotomy was later necessitated. Both procedures were complicated by postoperative bacteruria and funguria. She then underwent a laparoscopic dismembered pyeloplasty, again utilizing Lapra-Ty suture clips to secure the anastomosis. Postoperatively, her course was complicated by anastomotic extravasation, bacteriuria, and funguria. Subsequently, an antegrade nephrostogram revealed a 2.5-cm diverticulum just distal to the UPJ, which contained numerous 2- to 4-mm filling defects. Nephroscopic exploration of the pseudodiverticulum revealed numerous Lapra-Ty clips, which were basket extracted. The pseudodiverticulum was fulgurated with a holmium laser. She eventually had restricturing with recurrence of the pseudodiverticulum and was treated successfully by open ureterocalicostomy.

Anastomosis, Surgical↗