Hemostatic Properties of Four Devices for Partial Nephrectomy: A Comparative ex Vivo Study

Nonischemic or Ischemic Laparoscopic Partial Nephrectomy Using a Newly Developed Hybrid Energy Device in a Porcine Model

Purpose: To compare the efficacy of a newly developed hybrid pencil-type energy device (HD) generating simultaneously monopolar high-frequency electric energy and ultrasonic energy with that of a conventional device (CD) during laparoscopic partial nephrectomy (LPN). Materials and Methods: A total of 16 female pigs (32 kidneys) were divided into 4 groups of 4 animals (8 kidneys) each: nonischemic and ischemic HD-LPN groups, and nonischemic and ischemic CD-LPN groups. We performed bilateral LPN for each pig. HD alone was used in the HD-LPN group, whereas commercially available monopolar scissors and a soft coagulation system were used in the CD-LPN group. After observing the postoperative course for 14 days, we euthanized the animals and harvested the kidneys for histopathological observations. Results: We completed an LPN on a total of 32 kidneys. There were no cases of conversion to open surgery, nor were there any deaths or complications requiring treatment. For nonischemic LPN, LPN time was significantly shorter in the HD-LPN group than in the CD-LPN group (11.4 ± 4.8 vs 17.7 ± 5.3 minutes, p = 0.027). The decrease in postoperative hemoglobin was equally low in both groups. However, the frequency of TachoSil^® use was significantly higher in the CD-LPN group than in the HD-LPN group (6/8 [75%] vs 0/8 [0%], p = 0.007). For ischemic LPN, we found no significant differences in parameters such as LPN time and using TachoSil between the two groups. The depth of thermal injury was the most superficial in the nonischemic HD-LPN group in comparison with the other three groups. Conclusions: The application of an HD allowed nonischemic LPN to be performed safely in a short time with less blood loss and less thermal injury to the kidney in the porcine model. Additional clinical investigations of human kidneys are required.

Assessment of Probe-to-Specimen Distance Effect in Kidney Stone Treatment With Hydrodynamic Cavitation

The aim of this study is to focus on the effect of probe-to-specimen distance in kidney stone treatment with hydrodynamic bubbly cavitation. Cavitating bubbles were generated by running phosphate buffered saline (PBS) through stainless steel tubing of inner diameter of 1.56 mm at an inlet pressure of ∼10,000 kPa, which was connected to a 0.75 mm long probe with an inner diameter of 147 μm at the exit providing a sudden contraction and thus low local pressures. The bubbles were targeted on the surface of nine calcium oxalate kidney stones (submerged in a water pool at room temperature and atmospheric pressure) from three different distances, namely, 0.5 mm, 2.75 mm, and 7.75 mm. The experiments were repeated for three different time durations (5 min, 10 min, and 20 min). The experimental data show that amongst the three distances considered, the distance of 2.75 mm results in the highest erosion amount and highest erosion rate (up to 0.94 mg/min), which suggests that a closer distance does not necessarily lead to a higher erosion rate and that the probe-to-specimen distance is a factor of great importance, which needs to be optimized. In order to be able to explain the experimental results, a visualization study was also conducted with a high speed CMOS camera. A new correlation was developed to predict the erosion rates on kidney stones exposed to hydrodynamic cavitation as a function of material properties, time, and distance.

Prospective randomized study of radiofrequency versus ultrasound scalpels on functional outcomes of laparoscopic radical prostatectomy

BACKGROUND AND PURPOSE

Surgical treatment of patients with prostate cancer currently involves laparoscopic radical prostatectomy (LRP) or robot-assisted LRP. Continence and nerve-sparing procedures in these techniques are supported by dissection and hemostatic surgical devices powered by different types of energy. The aim of this study was to assess recovery of continence and erectile function after laparoscopic extraperitoneal radical prostatectomy comparing two surgical devices for dissection and hemostasis-radiofrequency (RF) and ultrasound (US) scalpels.

PATIENTS AND METHODS

A total of 132 men with localized prostate cancer were prospectively enrolled and scheduled for extraperitoneal LRP. Patients were randomly assigned to the RF group (LigaSure; n=66) or the US group (UltraCision; n=66). Outcomes were measured by the self-administered questionnaires (International Consultation on Incontinence Questionnaire-Urinary Incontinence [ICIQ-UI] and International Index of Erectile Function 5 [IIEF 5]) 15 days before surgery, 90 and 180 days after prostatectomy to assess recovery of urinary continence and erectile function.

RESULTS

No significant difference was found between the two groups regarding operative time, intra- and perioperative complications, or time of hospital stay. At 180 days after surgery, patients in the RF-treated group showed better recovery in terms of continence and erectile function compared with patients in the US group (ICIQ-UI: p=0.0016; IIEF 5: p=0.0352).

CONCLUSIONS

The use of the RF scalpel provided better functional outcomes compared with the US scalpel in patients undergoing extraperitoneal LRP. This might be attributed to the low contiguous damage of those tissues, which are not directly involved in dissection and hemostasis, achieved using the RF device.

Laparoscopic partial nephrectomy using a flexible CO2 laser fiber

BACKGROUND AND OBJECTIVES

Laparoscopic partial nephrectomy (LPN) is a challenging surgery that requires precise tissue cutting and meticulous hemostasis under warm ischemia conditions. In this study, we tested the feasibility of performing LPN using CO2 laser energy transmitted through a specialized flexible mirror optical fiber.

METHODS

General anesthesia and pneumoperitoneum were induced in 7 farm pigs. Various portions of a kidney, either a pole or a midportion of the kidney, were removed using a novel flexible fiber to transmit CO2 laser energy set at a power of 45W and energy per pulse of 100mJ. The collecting system was approximated with a suture or 2, but no hemostatic measures were taken besides applying a few pulses of the laser to bleeding points. The pigs were sacrificed 3 wk later.

RESULTS

Average renal mass removed was 18% of the total kidney weight. All pigs tolerated surgery well. Sharp renal cutting was accomplished in a single continuous incision, with minimal tissue charring and minimal blood loss (<10cc) in all animals. Necropsy revealed no peritoneal or retroperitoneal abnormalities. Histologic examination of the cut surface showed a thin sector of up to 100 m of coagulation necrosis.

CONCLUSIONS

We report on the first LPN done using a CO2 laser transmitted through a flexible fiber in an animal model. This novel application of the CO2 laser produced excellent parenchymal incision and hemostasis along with minimal damage to adjacent renal tissue, thus, potentially shortening ischemia time and kidney function loss. Further studies comparing this laser to standard technique are necessary to verify its usefulness for partial nephrectomy.

Electrosurgery in urology: recent advances

Inadequate hemostasis is one of the most important causes of morbidity and mortality following urological surgery. Despite the long-term usage of coagulation, there is an ongoing development of new devices, including bipolar transurethral resection of the prostate or new vessel-sealing devices. A thorough understanding of the advantages and disadvantages of these new instruments can improve the operative experience for both the urologist and patient. The optimal coagulation system should be small, efficient, easy to handle and with low heat spread. In this article, we analyze different electrothermal coagulation systems and modern tissue-sealing devices in urological applications with the aim to substantiate the advantages and disadvantages of each technique in terms of efficacy and safety.

Comparison between a 1.92-μm fiber laser and a standard HF-dissection device for nephron-sparing kidney resection in a porcine in vivo study

Nephron-sparing surgery was performed in a porcine model with a 1.92-μm fiber laser dissection device in comparison to a standard high-frequency dissection device. In nine pigs, general anesthesia and a median laparotomy were performed to expose both kidneys. On six kidneys (three HF and three laser) a partial renal parenchyma resection of the lower pole without opening of the renal pelvis was performed (group A). On 12 kidneys (four HF and eight laser), a hemi nephrectomy with opening of the renal pelvis was performed (group B). Total resection time including hemostasis of the remaining tissue was 501 ± 394 s in group "A-laser " vs. 176 ± 139 s in group "A-HF". For the group "B", the total resection time was 1174 ± 501 s (B laser) vs. 960 ± 407 s (B-HF). Blood loss was 28 ± 22 ml in group "A laser " vs. 15 ± 15 ml in group "A-HF". In group "B", the blood loss was 98 ± 73 ml (B laser) vs. 137 ± 118 ml (B-HF). No ischemic time for the kidneys was needed in group "A" for both dissection devices. In group "B", ischemia of the kidneys was performed three times during the eight laser procedures (420 ± 60 s) and only once at the four HF procedures (1,260 s). Healing process was observed over 4-6 weeks, survival rate was 100%, and no renal fistulas were found after the survival period. In conclusion, no significant differences were found between the compared dissection devices. However, the laser system with the flexible transmission fiber may have an advantage for a laparoscopic approach by steerable instruments.