Monopolar Device Research Articles

Focal osteonecrosis and severe chondrolysis following thermal capsulorrhaphy (SS-59)

The purpose of this paper is to warn surgeons of potentially catastrophic complications following thermal capsulorrhaphy of the shoulder. From 2000 to 2002, the senior author has seen in consultation, treated, and followed-up 5 cases of focal osteonecrosis and severe chondrolysis following thermal capsulorrhaphy performed elsewhere. The average patient age was 19.2 years at time of surgery. The dominant arm was involved in all 3 male patients and 2 female patients. All patients were throwing athletes. Thermal capsulorrhaphy was performed with bipolar thermal devices (Arthrocare in 3, Mitek Vapor in 2) in all cases. In no case was a monopolar device with temperature control utilized. Two patients also had suture anchor fixation and 1 had suture capsulorrhaphy. Areas of the capsule treated included 1 isolated rotator interval, 1 anterior-inferior and interval, and 3 global treatments of entire capsule. Postoperatively patients were immobilized from 3–6 weeks and underwent physical therapy including passive stretching. All patients immediate and subsequent postoperative courses were characterized by pain out of proportion to the procedure and intractable stiffness. All attempts to return to competitive throwing were unsuccessful. All 5 required subsequent surgeries: closed manipulation in 2, arthroscopy with capsular release in 5, biological resurfacing in 2, and glenohumeral fusion in 1. Postoperative range of motion was poor in all and pain relief incomplete. In 2 cases, litigation has been an issue. This condition differs from idiopathic or steroid-induced avascular necrosis: this osteonecrosis is focal, occasionally multi-focal, asymmetric, and osteonecrotic areas are smaller. Rapidity of collapse, deformity, and pain intensity is much greater, and changes on the glenoid surface occur simultaneously secondary to severe associated chondrolysis. The condition is extremely painful, rapidly progressive, and has resulted in reflex sympathetic dystrophy in 2 patients. The etiology of this complication may be focal subchondral bone death from direct application of heat combined with “superheating” of intra-articular fluid. It is difficult to determine whether this is direct thermal damage to the cartilage from heated fluid or direct damage to cartilage/bone vascular supply from heating the capsule. However, only the rotator interval was treated in 1 patient, which would not implicate a vascular source for avascular necrosis or chondrolysis. All patients were treated with bipolar thermal devices which have no temperature regulation. Based on surgery videotapes, direct trauma from anchors or instrumentation were not felt to be responsible. Given the young age of these patients, joint replacement is an unattractive option. Biologic resurfacing of the glenohumeral joint does offer pain relief and modest improvement in range of motion in these patients. Preoperatively informing young throwing athletes that this is a rare but potential complication is highly recommended. It is unclear whether earlier intervention with arthroscopic release would prevent progression. We believe that awareness and prevention of this complication is the most important message, and avoiding thermal capsulorrhaphy with bipolar devices is highly recommended.

Laparoscopic Partial Nephrectomy of Solid Renal Masses Without Hilar Clamping Using a Monopolar Radio Frequency Device

Partial nephrectomy is currently recommended for most amenable solid renal tumors, especially if they are exophytic and less than 4 cm. We reviewed our initial experience with laparoscopic partial nephrectomy for solid renal masses without clamping the renal vasculature using a monopolar device that uses radio frequency energy with low volume saline irrigation for simultaneous blunt dissection, hemostatic sealing and coagulation of the renal parenchyma (TissueLink, TissueLink Medical, Inc., Dover, New Hampshire). From September 2002 to April 2003, 10 patients underwent transperitoneal laparoscopic partial nephrectomy, including 9 with solid renal masses and 1 with a complex cyst. In all cases the renal hilum was dissected and the renal vessels were isolated but none had renal vascular clamping. The TissueLink DS dissecting sealer or Floating Ball (TissueLink Medical, Inc.) was used to dissect the tumor free bluntly, while simultaneously sealing and coagulating bleeders. Mean patient age was 54.6 years (range 42 to 72). Mean American Society of Anesthesiologists score was 2.3 (range 2 to 4). Mean tumor size was 3.9 cm (range 2.1 to 8). The mass had a peripheral location in 7 cases and a central location in 3. Mean operative time was 232 minutes (range 144 to 280) and mean blood loss was 352 ml (range 20 to 1000). One patient received blood transfusion and all tumor margins were negative. Mean hospital stay was 1.7 days (range 1 to 5) and pain medication use was minimal. One patient had a brief period of urine leakage from the lower pole calix, which was managed successfully by ureteral stenting and Foley catheter drainage of the bladder. Laparoscopic partial nephrectomy can be performed without renal vascular clamping. TissueLink technology allows complete tumor resection and provides adequate parenchymal hemostasis of the tumor bed. Its scant tissue charring production does not interfere with the pathological assessment of the tumor margin status.

An animal model study to clarify and investigate endoscopic tissue coagulation by using a new monopolar device

Background The purpose of this study was to evaluate a new device for endoscopic monopolar electrocoagulation and to develop ablative techniques by using this new device. Methods The new device consists of an overtube with a wire mesh electrode in an oval opening in the distal end and a balloon at the distal end. High-frequency electrical current was applied in 5 animal (swine) esophagi by using this specially designed monopolar electrocoagulation device. A total of 32 “lesions” were ablated by using blend electrosurgical waveforms for different time durations. The esophagi were then resected for histopathologic evaluation. Results Histopathologic study of the ablated lesions demonstrated that, by using the monopolar electrocoagulation device, different levels of degeneration of the mucosa and submucosa were achieved. The method for use of the device is fast and easy to apply. Conclusions The ablative procedure with the new overtube device is minimally invasive, clearly feasible, and easy to apply. This new device potentially can be used in patients for tissue ablation.

Necrotizing pancreatitis after radiofrequency destruction of pancreatic tumours

Background. Intraoperative radiofrequency (RF) can be used to treat multiple small pancreatic tumours. Patients and methods. Two patients with multiple pancreatic metastases from renal cancer were treated with RF destruction of the pancreatic tumours. The first was treated with a monopolar device and the second with a bipolar device. A high temperature (>90 °C) was used, and one patient underwent cooling of the intrapancreatic common bile duct. Results. The destruction of tumours was effective. However, the two patients presented post-operatively a severe necrotizing pancreatitis, with life-threatening hemorrhagic complications. Conclusion. RF destruction of pancreatic tumours is dangerous with current devices.

Hemostatic laparoscopic partial nephrectomy assisted by a water-cooled, high-density, monopolar device without renal vascular control

Objectives To evaluate the feasibility of laparoscopic partial nephrectomy assisted by a water-cooled, high-density, monopolar device (TissueLink Floating Ball). Methods Transperitoneal laparoscopic partial nephrectomy was performed without vascular control for four renal tumors in 3 patients. A flexible ultrasound probe was used to confirm tumor location and depth. Gerota’s fascia was opened distant from the tumor site. Renal fat was dissected from the renal parenchyma except for the fat overlying the tumor. The tumor resection area was marked 1 cm outside the boundaries of the tumor. After application of the TissueLink Floating Ball at the planned surgical margin, the tumor was resected with cold laparoscopic scissors. Bleeding from the vessels of the divided renal parenchyma was controlled with the Floating Ball if necessary. The specimen was sent for frozen section to confirm margin status. Results Mean estimated blood loss per tumor was 275 mL. The dissection extended to the collecting system in 2 of 4 cases. In 1 patient, a minor postoperative urine leak resolved spontaneously. Conclusions Use of the TissueLink Floating Ball facilitated resection of small renal tumors without renal vascular control. Although further study is necessary, water-cooled, high-density monopolar energy may have a role in laparoscopic partial nephrectomy.

Thermal Chondroplasty with Radiofrequency Energy

The purpose of this study was to examine the in vitro effects of three radiofrequency energy devices (two bipolar devices and one monopolar device) for the performance of thermal chondroplasty. Thirty-two fresh bovine femoral osteochondral sections (approximately 3 x 4 x 5 cm) from eight cows were divided into four groups (three treatment patterns and one sham-operated group with eight specimens per group). The three treatment patterns consisted of 1) radiofrequency energy delivered by a mechanical jig at 1 mm/sec in a contact mode (50 g of pressure), 2) radiofrequency energy delivered by a mechanical jig at 1 mm/sec in a noncontact mode (1 mm between probe tip and articular cartilage surface), and 3) radiofrequency energy smoothing of abraded cartilage during arthroscopic visualization. Thermal smoothing of the abraded cartilage surface was accomplished with all three devices. Significant chondrocyte death, as determined by confocal laser microscopy and cell viability staining, was observed with each device. The bipolar radiofrequency systems penetrated 78% to 92% deeper than the monopolar system. The bipolar systems penetrated to the level of the subchondral bone in all osteochondral sections during arthroscopically guided paintbrush pattern treatment. Radiofrequency energy should not be used for thermal chondroplasty until further work can establish consistent methods for limiting the depth of chondrocyte death while still achieving a smooth articular for thermal chondroplasty until further work can establish consistent methods for limiting the depth of chondrocyte death while still achieving a smooth articular surface.

A comparison of pulpal and tactile detection threshold levels in young adults

Pulpal and tactile sensory detection threshold (SDT) values of the maxillary and mandibular incisor and canine teeth were determined and recorded for young adult subjects at three test sessions. A commercially available monopolar pulp-testing device was used to determine pulpal SDT values, and von Frey hairs were used to determine the tactile SDT values. Statistical analysis of the data indicated that the pulpal and tactile test procedures were sufficiently reliable in identifying what is defined as the true SDT value for both parameters. The study confirmed the constancy of these SDT values over days and the independence of the values for jaw, side, and sex. SDT values were influenced, however, by tooth type, with canine teeth displaying higher tactile and pulpal values than the central and lateral incisor teeth. These data should provide a suitable baseline for a longitudinal study to identify the SDT fluctuations known to occur in tooth pulp and dental supporting tissues in a growing human population.