Application of Ice Cold Irrigation During Vascular Pedicle Control of Robot-Assisted Radical Prostatectomy: EnSeal Instrument Cooling to Reduce Collateral Thermal Tissue Damage

Is endourological intervention a suitable treatment option in the management of iatrogenic thermal ureteral injury? A contemporary case series

BACKGROUND

Iatrogenic ureteral injury (IUI) is relatively rare, however, can cause sepsis, kidney failure, and death. Most cases of IUI are not recognized until the patient presents with symptoms following pelvic surgery or radiotherapy. Recently, minimally invasive approaches have been used more frequently in the treatment of IUI. This study evaluates urological intervention success rates and long-term clinical outcomes according to the type of IUI following hysterectomy.

METHODS

Twenty-seven patients who underwent surgery due to IUI in our clinic following hysterectomy were evaluated between January 2011 and April 2018. Patients were classified according to the time of diagnosis of IUI. The IUI cases diagnosed within the first 24 h following hysterectomy were designated as "immediate" IUI, while that diagnosed late period was considered 'delayed' IUI. The type of IUI was categorized as "cold transection" if it was due to surgical dissection or ligation without any thermal energy, and "thermal injury" if it was related to any energy-based surgical device. Patient information, laboratory and perioperative data, imaging studies, and complications were assessed retrospectively.

RESULTS

All cases of delayed diagnosis IUI were secondary to laparoscopic hysterectomy (P = 0.041). Patients with thermal injury to the ureter were mostly diagnosed late (delayed) (P = 0.029). While 31% of the patients who underwent endourological intervention were diagnosed immediately, 69% of them were diagnosed as delayed. These rates were roughly reversed for open reconstructive surgery: 73% and 27% (P = 0.041), respectively. We detected eight ureteral complications in our patient cohort following the urological intervention. In all these failed cases, the cause of IUI was a thermal injury (P = 0.046) and the patients had received endourological treatment (P = 0.005). No complications were detected in patients who undergo open urological reconstructive surgery. While one of the patients who developed urological complications had an immediate diagnosis, seven were in the delayed group (P = 0.016).

CONCLUSION

Endourological intervention is performed more frequently in delayed diagnosed IUI following hysterectomy, however, the treatment success rate is low if thermal damage has developed in the ureter. Surgical reconstruction is should be preferred in these thermal injury cases to avoid further ureter-related complications.

Intestinal Injury by Heat Conduction from Surgical Sealing Devices

Background:

There have been no investigations of intestinal injury induced by surgical sealing devices, especially focusing heat conduction from the back of active blades during laparoscopic surgery.

Objective:

This study of damage to the small intestine by heat conduction from the back of active blades both physically and histopathologically was performed to establish safe usage of surgical sealing devices.

Materials and method:

We compared seven types of bipolar sealing device and two types of ultrasonic coagulating shear in an animal model simulating laparoscopic surgery. Time-dependent changes in heat conduction from the back of active blades were measured using a direct contact thermometer during intracorporeal activation. Histopathological damage to the small intestine by the back of active blades in laparoscopic surgical application was evaluated. The backs of active blades were activated while attached to the serosa of the small intestine. The depths of histopathological changes were measured to evaluate the thermal effects of surgical sealing devices.

Results:

Most devices generated temperatures >70°C even on the back of active blades. There were no significant differences in duration for cooling to ≤50°C among these devices. All devices induced histopathological heat damage in the submucosal layer or deeper.

Conclusions:

Regardless of type, the backs of active blades of surgical sealing devices conduct high temperatures and can induce heat damage in the small intestine. Surgical sealing devices should not be activated while attached to surrounding tissue or organs in laparoscopic surgery.

Physiological and Biochemical Responses to Continuous Saline Irrigation Inside the Abdominal Cavity in Anesthetized Pigs

BACKGROUND

Water-filled laparoendoscopic surgery (WaFLES) has been proposed as a novel surgical system achieving a wide surgical field in the intra- and extraperitoneal space with continuous irrigation of isotonic fluid into the field. Despite its technical feasibility and advantages, the safety of the technique, particularly with respect to physiological functions, has not been evaluated.

METHODS

Various types of minor abdominal surgeries were performed under general anesthesia in nine adult pigs either by conventional laparoscopy (n = 3) or WaFLES (n = 6). In addition to esophageal temperature and body weight, cardiorespiratory variables such as blood pressure, heart rate, and arterial blood gas parameters were compared before and after the surgeries. Blood samples were obtained for assessing changes in biochemical parameters before and after the surgeries.

RESULTS

Three to seven hours of various surgeries were completed without critical cardiorespiratory events in all animals. Oxygenation and ventilation were maintained regardless of the techniques used for the surgeries. A minor increase of body weight (2.5% of initial body weight), metabolic acidosis, hyperkalemia, and impaired hepatic function were observed after WaFLES surgeries.

CONCLUSIONS

The preliminary study indicated no serious immediate adverse effects of the WaFLES technique.

Investigation of factors affecting hypothermic pelvic tissue cooling using bio-heat simulation based on MRI-segmented anatomic models

This study applied a simulation method to map the temperature distribution based on magnetic resonance imaging (MRI) of individual patients, and investigated the influence of different pelvic tissue types as well as the choice of thermal property parameters on the efficiency of endorectal cooling balloon (ECB). MR images of four subjects with different prostate sizes and pelvic tissue compositions, including fatty tissue and venous plexus, were analyzed. The MR images acquired using endorectal coil provided a realistic geometry of deformed prostate that resembled the anatomy in the presence of ECB. A single slice with the largest two-dimensional (2D) cross-sectional area of the prostate gland was selected for analysis. The rectal wall, prostate gland, peri-rectal fatty tissue, peri-prostatic fatty tissue, peri-prostatic venous plexus, and urinary bladder were manually segmented. Pennes' bioheat thermal model was used to simulate the temperature distribution dynamics, by using an in-house finite element mesh based solver written in MATLAB. The results showed that prostate size and periprostatic venous plexus were two major factors affecting ECB cooling efficiency. For cases with negligible amount of venous plexus and small prostate, the average temperature in the prostate and neurovascular bundles could be cooled down to 25 °C within 30 min. For cases with abundant venous plexus and large prostate, the temperature could not reach 25 °C at the end of 3 h cooling. Large prostate made the cooling difficult to propagate through. The impact of fatty tissue on cooling effect was small. The filling of bladder with warm urine during the ECB cooling procedure did not affect the temperature in the prostate or NVB. In addition to the 2D simulation, in one case a 3D pelvic model was constructed for volumetric simulation. It was found that the 2D slice with the largest cross-sectional area of prostate had the most abundant venous plexus, and was the most difficult slice to cool, thus it may provide a conservative prediction of the cooling effect. This feasibility study demonstrated that the simulation tool could potentially be used for adjusting the setting of ECB for individual patients during hypothermic radical prostatectomy. Further studies using MR thermometry are required to validate the in silico results obtained using simulation.

Lateral temperature spread of monopolar, bipolar and ultrasonic instruments for robot-assisted laparoscopic surgery

OBJECTIVE

To assess critical heat spread of cautery instruments used in robot-assisted laparoscopic (RAL) surgery.

MATERIALS AND METHODS

Thermal spread along bovine musculofascial tissues was examined by infrared camera, histology and enzyme assay. Currently used monopolar, bipolar and ultrasonic laparoscopic instruments were investigated at various power settings and application times. The efficacy of using an additional Maryland clamp as a heat sink was evaluated. A temperature of 45 °C was considered the threshold temperature for possible nerve damage.

RESULTS

Monopolar instruments exhibited a mean (sem) critical thermal spread of 3.5 (2.3) mm when applied at 60 W for 1 s. After 2 s, the spread was >20 mm. For adjustable bipolar instruments the mean (sem) critical thermal spread was 2.2 (0.6) mm at 60 W and 1 s, and 3.6 (1.3) mm at 2 s. The PK and LigaSure forceps had mean (sem) critical thermal spreads of 3.9 (0.8) and 2.8 (0.6) mm respectively, whereas the ultrasonic instrument reached 2.9 (0.8) mm. Application of an additional Maryland clamp as a heat sink, significantly reduced the thermal spread. Histomorphometric analyses and enzyme assay supported these findings.

CONCLUSIONS

All coagulation devices used in RAL surgery have distinct thermal spreads depending on power setting and application time. Cautery may be of concern due to lateral temperature spread, causing potential damage to sensitive structures including nerves. Our results provide surgeons with a resource for educated decision-making when using coagulation devices during robotic procedures.

Comparative studies of energy sources in gynecologic laparoscopy

Energy sources incorporating "vessel sealing" capabilities are being increasingly used in gynecologic laparoscopic surgery although conventional monopolar and bipolar electrosurgery remain popular. The preference for one device over another is based on a combination of factors, including the surgeon's subjective experience, availability, and cost. Although comparative clinical studies and meta-analyses of laparoscopic energy sources have reported small but statistically significant differences in volumes of blood loss, the clinical significance of such small volumes is questionable. The overall usefulness of the various energy sources available will depend on a number of factors including vessel burst pressure and seal time, lateral thermal spread, and smoke production. Animal studies and laboratory-based trials are useful in providing a controlled environment to investigate such parameters. At present, there is insufficient evidence to support the use of one energy source over another.

Robotic-assisted radical prostatectomy after the first decade: surgical evolution or new paradigm

Early studies indicate that robotic-assisted radical prostatectomy (RARP) has promising short-term outcomes; however, RARP is beyond its infancy, and the long-term report cards are now beginning. The important paradigm shift introduced by RARP is the reevaluation of the entire open radical prostatectomy experience in surgical technique by minimizing blood loss and complications, maximizing cancer free outcomes, and a renewed assault in preserving quality of life outcomes by many novel mechanisms. RARP provides a new technical “canvas” for surgical masters to create upon, and in ten years, has reinvigorated a 100-year-old “gold standard” surgery.

The application of regional hypothermia using transrectal cooling during radical prostatectomy: mitigation of surgical inflammatory damage to preserve continence

Preservation of continence and sexual function continues to be a formidable quality-of-life issue regarding outcomes after radical prostatectomy. There is little argument that physical preservation of the nerves and sphincters is a critical component to achieving success in these domains. Previously demonstrated factors such as advancing age, deteriorating physical health status, and subnormal baseline potency negatively impact outcomes. Our hypothesis, however, has been that inflammatory response to surgery has a large impact on surgical outcomes of prostatectomy. Trauma-induced inflammation could account for variation in recovery despite nearly identical surgery on many patients, especially in high-volume surgeons. In other words, we suggest and maintain that younger and healthier patients tolerate and/or recover better from the trauma/inflammation of surgery. Those who do not recover as well may have altered inflammatory response to injury. A common response to decrease inflammation in response to physical injury would be as simple as to cool the injury with ice. Previous neurologic studies have suggested that using ice during surgical intervention can reduce the inflammatory damage. Therefore, we applied this concept that preemptive hypothermia could reduce inflammation to the robot-assisted prostatectomy procedure to potentially lead to improved continence and potency outcomes. In 2009, we introduced the concept of regional hypothermia via an endorectal cooling balloon during robot-assisted radical prostatectomy (RARP). We have published our single institution data demonstrating a significant reduction of overall incontinence. Defining continence as zero-pads, our overall 1-year incontinence has been reduced by 70% (from 13% to 4%). Severe incontinence, defined as two or more pads, was likewise reduced by 70% (from 2.9% to 0.9%). Regional hypothermia used during the time of surgery represents a novel strategy for minimizing inflammation and subsequent muscle and nerve damage in RARP.

Evaluation of EnSeal®, an adaptive bipolar electrosurgical tissue-sealing device

Relatively few, and inconsistent, data are available in the literature about the properties of EnSeal®, an electrosurgical tissue-sealing device. For this reason, we conducted control safety tests on experimental pigs. The mean burst pressure of sealed vessels (2-7 mm in diameter) proved to be 873.89 ± 120.57 mmHg (n = 60). Surface temperature increased to 69.25 ± 0.98 °C in average (n = 22). The mean diameter of the collateral microscopic thermal injury zone was found to be 0.28 ± 0.04 mm, and it did not show significant differences among the groups of tissues studied (n = 183). During our studies, the device worked reliably and met the relevant requirements in all cases. It can be established that EnSeal® enables high-safety clinical interventions at high blood pressure values, in different tissues and even at sites adjacent to heat-sensitive tissues, and thus it paves the way for new operative solutions in both human and veterinary surgery. In our opinion, the discrepancies between data reported in the literature arise from differences in the design of studies and in the designated limit values. To ensure standardisation, we recommend the use of the nitroblue-tetrazolium chloride/lactate dehydrogenase (NBTC/LDH) enzyme histochemical technique for studying thermal injury induced by the different performance levels and application times of devices operating with electromagnetic energy.

Laparoscopic cryptorchidectomy and ovariectomy in standing horses using the EnSeal® tissue-sealing device

In the present series of cases, 8 laparoscopic cryptorchidectomies and 4 laparoscopic ovariectomies were carried out in sedated standing horses. Sedation involved a lesser anaesthesiological risk than does general anaesthesia. As compared to laparotomic exposure, the minimally invasive laparoscopic intervention provided better visualisation, shorter operative time and faster recovery. The blood vessels supplying the testes and ovaries and the suspensory ligaments of the organs were sealed and cut with EnSeal®, an adaptive bipolar electrosurgical blood vessel- and tissue-sealing device. The clinical use of the blood vessel- and tissue-sealing device proved to be successful in all cases. Gradual separation of the intact tissue from the treated, compacted, dehydrated and homogenised tissue areas and occlusion of the lumen of blood vessels treated with the device could be observed in all histological sections. To the best of our knowledge, this is the first report on the use of EnSeal® for laparoscopic cryptorchidectomy and ovariectomy in horses.

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.

Basis for the use of localized hypothermia during radical pelvic surgery

Controlled tissue cooling, or hypothermia, has been used therapeutically for decades to mitigate the negative effects of traumatic, ischemic, and surgical insults. When applied systemically, moderate hypothermia can attenuate or prevent the extent of neurologic sequelae. Localized hypothermia, on the other hand, has the capacity to reduce tissue edema, suppress inflammation, and minimize the severity of peripheral nerve injury. Therapeutic hypothermia has been used in critical care, neurosurgery, ophthalmology, otolaryngology, cardiothoracic surgery and most recently in urology. Nerve injury during radical pelvic surgery can result in urinary incontinence or retention, impotence and bowel dysfunction. Localized hypothermia during radical prostatectomy has demonstrated improved recovery of urinary continence and erectile function, and similar benefits might be observed in other types of radical pelvic surgery.

Safe use of ultrasonically activated devices based on current studies

Ultrasonically activated devices (USADs) are a widely used alternative to suture ligation and clips in open and laparoscopic surgery because of their fast and easy control of bleeding without significant complications. By inducing protein denaturation and forming coaptive coagulation to seal vessels for cutting tissue, USADs result in reduced operating time, blood loss and hospital stay. Recently, various other types of vessel sealers have become available. In this article, we summarize the mechanism, efficacy and the advantages and disadvantages of USADs for appropriate use in surgery.