Temperature safety profile of laparoscopic devices: Harmonic ACE (ACE), Ligasure V (LV), and plasma trisector (PT)

Incidence of residual biologic debris and contamination of reused bipolar vessel sealing devices after ethylene oxide sterilization following splenectomy

OBJECTIVE

The aim of the present study was to quantify the amount of biologic debris present within disposable bipolar vessel sealing devices after each use for canine splenectomies and determine the aerobic bacterial load of the debris following instrument resterilization with ethylene oxide.

STUDY DESIGN

Prospective observational clinical study.

STUDY POPULATION

Client-owned dogs (n = 40) presenting to a single specialty hospital for open, routine, or emergency splenectomies.

METHODS

A total of 16 bipolar vessel sealing devices were randomly assigned to undergo one, two, three, or four splenectomies, manual hand cleanings, and ethylene oxide sterilizations before being dismantled. After final use and sterilization, each handset was agitated in phosphate-buffered saline before disassembly, which was submitted for aerobic culture. Following aseptic disassembly, all biological residue was photo-documented, collected, quantified using a subjective scoring system, and submitted for culture.

RESULTS

Biologic debris was present within the inner mechanics of all devices, specifically under the blade used for vessel transection. A linear increase in debris was not appreciated amongst devices used once versus devices used multiple times. None of the devices nor any of the biologic debris cultured positive following sterilization with ethylene oxide.

CONCLUSION

The presence of biologic debris was documented after the initial use of disposable bipolar vessel sealing devices, but no devices or debris yielded positive culture results following ethylene oxide sterilization after splenectomies.

CLINICAL SIGNIFICANCE

Increased risk of iatrogenic surgical site contamination from reused vessel sealing devices is unlikely when they have been cleaned and sterilized with ethylene oxide after up to four splenectomy surgeries.

Comparison of quartz and sapphire optical chambers for infrared laser sealing of vascular tissues using a reciprocating, side-firing optical fiber: Simulations and experiments

INTRODUCTION

Infrared (IR) lasers are being tested as an alternative to radiofrequency (RF) and ultrasonic (US) surgical devices for hemostatic sealing of vascular tissues. In previous studies, a side-firing optical fiber with elliptical IR beam output was reciprocated, producing a linear IR laser beam pattern for uniform sealing of blood vessels. Technical challenges include limited field-of-view of vessel position within the metallic device jaws, and matching fiber scan length to variable vessel sizes. A transparent jaw may improve visibility and enable custom treatment.

METHODS

Quartz and sapphire square optical chambers (2.7 × 2.7 × 25 [mm3 ] outer dimensions) were tested, capable of fitting into a 5-mm-OD laparoscopic device. A 1470 nm laser was used for optical transmission studies. Razor blade scans and an IR beam profiler acquired fiber (550-µm-core/0.22NA) output beam profiles. Thermocouples recorded peak temperatures and cooling times on internal and external chamber surfaces. Optical fibers with angle polished distal tips delivered 94% of light at a 90° angle. Porcine renal arteries with diameters of 3.4 ± 0.7 mm (n = 13) for quartz and 3.2 ± 0.7 mm (n = 14) for sapphire chambers (p > 0.05), were sealed using 30 W for 5 s.

RESULTS

Reflection losses at material/air interfaces were 3.3% and 7.4% for quartz and sapphire. Peak temperatures on the external chamber surface averaged 74 ± 8°C and 73 ± 10°C (p > 0.05). Times to cool down to 37°C measured 13 ± 4 s and 27 ± 7 s (p < 0.05). Vessel burst pressures (BP) averaged 883 ± 393 mmHg and 412 ± 330 mmHg (p < 0.05). For quartz, 13/13 (100%) vessels were sealed (BP > 360 mmHg), versus 9/14 (64%) for sapphire. Computer simulations for the quartz chamber yielded peak temperatures (78°C) and cooling times (16 s) similar to experiments.

CONCLUSIONS

Quartz is an inexpensive material for use in a laparoscopic device jaw, providing more consistent vessel seals and faster cooling times than sapphire and current RF and US devices.

Absorbable Clips Applied in Thoracoscopic Anatomical Lung Resection in Younger Children

OBJECTIVES

This study aims to evaluate the feasibility and safety of a 5-mm absorbable clips applied in thoracoscopic anatomical lung resection in younger children.

METHODS

Demographic data and intra- and postoperative parameters of the two groups (Abs-o-lock® group and Hem-o-lok® group) were reviewed. In the Abs-o-lock® group, 5-mm absorbable clips were used in thoracoscopic anatomical lung resection on all patients from January 2020 to March 2021. In the Hem-o-lok® group, 5-mm Hem-o-lok® clips were used from January to December 2019. The primary outcomes were the one-time success rate of ligation, major bleeding rate, intraoperative dislodgement rate and operative time, which were compared between the two groups.

RESULTS

There were 224 patients involved in this study, of whom 103 were in the Abs-o-lock® group and 121 were in the Hem-o-lok® group. The one-time success rate of ligation was 96.5% in the Abs-o-lock® group and 98.9% in the Hem-o-lok® group (p < 0.05). No major bleeding occurred in either group. The intraoperative dislodgement rate did not significantly differ between the two groups (p = 1.0). The operative time consumed in the Abs-o-lock® group was much longer than that in the Hem-o-lok® group for subgroups of resection of extralobar sequestration (p < 0.05), lobectomy (p < 0.05) and segmentectomy (p < 0.05).

CONCLUSIONS

Compared to Hem-o-lok® clips, it is feasible and safe to apply 5-mm absorbable clips for vessel sealing during thoracoscopic anatomical lung resection in younger children.

"In Vitro" Evaluation of Energy-Based Sealing of Graft Side Branches in Bypass Surgery

INTRODUCTION

Our objective was to compare the in vitro efficacy of electrothermal bipolar [EB] vessel sealing and ultrasonic harmonic scalpel [HS] versus mechanical interruption, with conventional ties or surgical clips (SC), in sealing saphenous vein (SV) collaterals, during its eventual preparation for bypass surgery.

METHODS

Experimental in vitro study on 30 segments of SV. Each fragment included two collaterals at least 2 mm in diameter. One of them was sealed by ligation with 3/0 silk ties (control) and the other one with EB (n = 10), HS (n = 10) or medium-6 mm SC (n = 10). After incorporation in a closed circuit with pulsatile flow, the pressure was progressively increased until causing rupture. Collateral diameter, burst pressure, leak point, and histological study were recorded.

RESULTS

Burst pressure was higher for SC (1320.20 ± 373.847 mmHg) as compared with EB (942.2 ± 344.9 mmHg, p = 0.065), and especially with HS (637.00 ± 320.61 mmHg, p = 0.0001). No statistically significant difference between EB and HS was found, and bursting always happened at supraphysiological pressures. The leak point for HS was always detected in the sealing zone (10/10), while for EB and SC, it occurred in the sealing zone only in 6/10(60%) and 4/10(40%), respectively (p = 0.015).

CONCLUSIONS

Energy delivery devices showed similar efficacy and safety in sealing of SV side branches. Although bursting pressure was lower than with tie ligature or SC, non-inferiority efficacy was shown at the range of physiological pressures in both, EB and HS. Due to their speed and easy handling, they may be useful in the preparation of the venous graft during revascularization surgery. However, remaining questions about healing process, potential spread of tissue damage and sealing durability, will require further analysis.

Minimizing thermal damage using self-cooling jaws for radiofrequency intestinal tissue fusion

INTRODUCTION

Radiofrequency (RF)-induced tissue fusion shows great potential in sealing intestinal tissue without foreign materials. To improve the performance of RF-induced tissue fusion, a novel self-cooling jaw has been designed to minimize thermal damage during the fusion.

MATERIAL AND METHODS

The prototype of self-cooling jaws was developed and manufactured. A total number of 60 mucosa-to-mucosa fusions were conducted using ex-vivo porcine intestinal segments with the proposed design and conventional bipolar jaws. The effects of intestinal fusion were evaluated based on temperature curves, burst pressure, thermal damage, and histological appearances.

RESULTS

The self-cooling jaws showed significant decrease in temperature during the fusion process. An optimal burst pressure (5.7 ± 0.5 kPa) and thermal damage range (0.9 ± 0.1 mm) were observed when the applied RF power was 100 W. The thermal damage range of the prototype has almost decreased 36% in comparison with the conventional bipolar jaws (1.4 ± 0.1 mm). The histological observation revealed that a decrease of thermal damage was achieved through the application of self-cooling jaws.

CONCLUSIONS

The self-cooling jaws were proved to be effective for reducing the thermal damage during RF-induced tissue fusion, which could potentially promote the clinical application of tissue fusion techniques in the future.

LigaSure versus Conventional Parotidectomy: A Systematic Review and Meta-Analysis

Surgery with parotidectomy is the preferable treatment for most parotid tumors. Our meta-analysis compared the differences between the use of the LigaSure (LS) device and the conventional suture ligation technique (CT) in parotidectomies. A literature search in databases including EMBASE, MEDLINE, and the Cochrane Library was carried out. Studies including parotidectomy using LS and CT were included with the intraoperative and postoperative parameters collected. Continuous operative time data were measured by mean differences (MDs). Discrete data on postoperative complications, including facial palsy, postoperative bleeding, and salivary complications, were evaluated with risk differences (RDs). All values were reported with 95% confidence intervals (CIs). Five studies were included in our meta-analysis. The pooled analysis demonstrated a significant reduction in operative time in the LS group (MD: −21.92; 95% CI, −30.18 to −13.66). In addition, the analysis indicated that the incidence of postoperative complications, including permanent facial palsy (RD, −0.01; 95% CI, −0.06 to 0.05), temporary facial palsy (RD, 0.00; 95% CI, −0.03 to 0.04), salivary complications (RD, −0.01; 95% CI, −0.08 to 0.06), and postoperative bleeding (RD, −0.02; 95% CI, −0.07 to 0.04), were all similar between the LS group and the CT group. According to the results, the LS device appears to be a safe and useful tool and could shorten the operative time in patients needing parotidectomy.

Novel multifunctional robotically assisted bipolar instrument for simultaneous radiofrequency sealing and transection: preclinical and single-center experience

Background

A novel robotic-assisted bipolar radiofrequency (RF) multifunctional vessel seal-and-transection instrument (SynchroSeal, Intuitive Surgical, Inc., Sunnyvale, CA) has been developed. The objective of the current paper is to describe the design of SynchroSeal based on bench studies, assess the safety of SynchroSeal in ex vivo and in vivo porcine studies, and provide early clinical context.

Methods

SynchroSeal grasping, energy activation time, and jaw temperature were evaluated with those of the Harmonic Ace+7. Data were analyzed with descriptive statistics, with Mann–Whitney for comparisons and statistical significance p < 0.05. Ex vivo and in vivo animal safety assessments of tissue after SynchroSeal use were evaluated for burst pressure, thermal spread, and acute sealing. Last, a single-center analysis of the technical metrics of SynchroSeal and Vessel Sealer Extend (robotically assisted seal-and-transection instrument) in bariatric cases is provided.

Results

Bench studies of SynchroSeal and Harmonic Ace+7 evidenced SynchroSeal’s greater slip resistance force (8.4 ± 1.0 vs. 3.1 ± 0.4 N; p = 0.0002), lower grip pressure (3.0 ± 0.2 vs. 4.2 ± 0.5 kg/cm²; p = 0.0002), faster seal time (1.5 ± 0.4 vs. 11.6 ± 2.5 s; p < 0.0001), lower mean jaw temperature (109.7 ± 7.2 vs. 247.4 ± 8.6 °C; p = 0.0051), and faster cooling to 40 °C (53.6 ± 2.1 vs. 68.0 ± 3.5 s; p = 0.0051). SynchroSeal’s mean burst pressures after seal-and-transection and seal only modes were, respectively, 1169.1 ± 393.1 mmHg and 1159.2 ± 454.6 mmHg. Mean thermal spreads were, respectively, 1.2 ± 0.6 mm and 1.5 ± 0.55 mm. In the chronic animal study, 102 vessels were sealed; at 3 weeks post-procedure, there was no evidence of leakage or adverse events, such as non-target tissue thermal spread or tissue damage. In bariatrics cases, SynchroSeal was activated more frequently per case; however, its mean activation time was significantly shorter than Vessel Sealer Extend. No adverse events were reported for either device.

Conclusions

SynchroSeal’s multifunctional design provides enhanced sealing and transection capabilities with an acceptable safety profile.

Reciprocating Side-Firing Fiber for Laser Sealing of Blood Vessels

Infrared lasers may provide faster and more precise sealing of blood vessels and with lower jaw temperatures than ultrasonic and electrosurgical devices. This study explores an oscillating or reciprocating side-firing optical fiber method for transformation of a circular laser beam into a linear beam, necessary for integration into a standard 5-mm-diameter laparoscopic device, and for uniform irradiation perpendicular to the vessel length. A servo motor connected to a side-firing, 550-μm-core fiber, provided linear translation of a 2.0-mm-diameter circular beam over either 5 mm or 11 mm scan lengths for sealing small or large vessels, respectively. Laser seals were performed, ex vivo, on a total of 20 porcine renal arteries of 1-6 mm diameter (n = 10 samples for each scan length). Each vessel was compressed to a fixed 0.4-mm-thickness, matching the 1470-nm laser optical penetration depth. Vessels were irradiated with fluences ranging from 636 J/cm² to 716 J/cm². A standard burst pressure (BP) setup was used to evaluate vessel seal strength. The reciprocating fiber produced mean BP of 554 ± 142 and 524 ± 132 mmHg, respectively, and consistently sealing blood vessels, with all BP above hypertensive (180 mmHg) blood pressures. The reciprocating fiber provides a relatively uniform linear beam profile and aspect ratio, but will require integration of servo motor into a handpiece.

Temperature profile and residual heat of monopolar laparoscopic and endoscopic dissection instruments

BACKGROUND

Endoscopic and laparoscopic electrosurgical devices (ED) are of great importance in modern medicine but can cause adverse events such as tissue injuries and burns from residual heat. While laparoscopic tools are well investigated, detailed insights about the temperature profile of endoscopic knives are lacking. Our aim is to investigate the temperature and the residual heat of laparoscopic and endoscopic monopolar instruments to increase the safety in handling ED.

METHODS

An infrared camera was used to measure the temperature of laparoscopic and endoscopic instruments during energy application and to determine the cooling time to below 50 °C at a porcine stomach. Different power levels and cutting intervals were studied to investigate their impact on the temperature profile.

RESULTS

During activation, the laparoscopic hook exceeded 120 °C regularly for an up to 10 mm shaft length. With regards to endoknives, only the Dual Tip Knife showed a shaft temperature of above 50 °C. The residual heat of the laparoscopic hook remained above 50 °C for at least 15 s after activation. Endoknives cooled to below 50 °C in 4 s. A higher power level and longer cutting duration significantly increased the shaft temperature and prolonged the cooling time (p < 0.001).

CONCLUSION

Residual heat and maximum temperature during energy application depend strongly on the chosen effect and cutting duration. To avoid potential injuries, the user should not touch any tissue with the laparoscopic hook for at least 15 s and with the endoknives for at least 4 s after energy application. As the shaft also heats up to over 120 °C, the user should be careful to avoid tissue contact during activation with the shaft. These results should be strongly considered for safety reasons when handling monopolar ED.

Comparative analysis of peri-operative outcomes following total laparoscopic hysterectomy with conventional bipolar-electrosurgery versus high-pressure pulsed LigaSure use

Objectives:

Materials and Methods:

Results:

Conclusion:

Improving Voice Outcomes After Thyroid Surgery - Review of Safety Parameters for Using Energy-Based Devices Near the Recurrent Laryngeal Nerve

Technological advances in thyroid surgery have rapidly increased in recent decades. Specifically, recently developed energy-based devices (EBDs) enable simultaneous dissection and sealing tissue. EBDs have many advantages in thyroid surgery, such as reduced blood loss, lower rate of post-operative hypocalcemia, and shorter operation time. However, the rate of recurrent laryngeal nerve (RLN) injury during EBD use has shown statistically inconsistent. EBDs generate high temperature that can cause iatrogenic thermal injury to the RLN by direct or indirect thermal spread. This article reviews relevant medical literatures of conventional electrocauteries and different mechanisms of current EBDs, and compares two safety parameters: safe distance and cooling time. In general, conventional electrocautery generates higher temperature and wider thermal spread range, but when applying EBDs near the RLN adequate activation distance and cooling time are still required to avoid inadvertent thermal injury. To improve voice outcomes in the quality-of-life era, surgeons should observe safety parameters and follow the standard procedures when using EBDs near the RLN in thyroid surgery.

Heat production during pulmonary artery sealing with energy vessel-sealing devices in a swine model

OBJECTIVES

Energy vessel-sealing devices are being increasingly utilized to seal pulmonary artery (PA) branches during lobectomy. Heat from these devices can potentially injure surrounding tissues. We evaluated heat production from devices in a live animal model.

METHODS

PA branches were sealed in pigs with 4 energy vessel-sealing devices: 2 ultrasonic (US), 1 advanced bipolar or 1 mixed US and bipolar (mixed) device. Thermocouples were implanted in tissue surrounding the PA branch being sealed to measure tissue temperature. A thermal camera measured the sealing site and the temperatures of the instruments. Pathological analysis was performed on PA stumps to identify thermal damage.

RESULTS

A total of 37 PA branches were sealed in 4 pigs. Maximum tissue heat measured by the thermocouples for the 2 US, advanced bipolar and mixed devices was 42, 39, 42 and 46°C, respectively. The mean tissue temperatures at the site of the sealing measured with the thermal camera were 78, 75, 70 and 82°C (P = 0.834) and the mean instrument blade temperatures were 224, 195, 83 and 170°C (P = 0.000005) for the 2 US, advanced bipolar and mixed devices, respectively. The mean diameter of the region with tissue reaching 60°C or more measured with the thermal camera was between 4 and 6 mm for the 4 devices (P = 0.941). On pathological analysis, PA stumps had either thermal damage on the adventitia and external media (26/37) or transmural damage (11/37) at 1 mm from sealed site.

CONCLUSIONS

A 3-mm safety margin between the instrument blades and vital structures is recommended. Instrument blades can reach high temperatures that may cause tissue damage.

Computational Simulations for Infrared Laser Sealing and Cutting of Blood Vessels

Blood vessel burst pressures were simulated and predicted for sealing and cutting of vessels in a two-step process, using low (<25 W), medium (~100 W), and high (200 W) power lasers at a wavelength of 1470 nm. Monte Carlo optical transport, heat transfer, Arrhenius integral tissue damage simulations, and vessel pressure equations were utilized. The purpose of these studies was to first validate the numerical model by comparison with experimental results (for low and medium power) and then to use the model to simulate parameters that could not be experimentally tested (for high power). The goal was to reduce the large range of parameters (power, irradiation time, and linear beam dimensions) to be tested in future experiments, for achieving short vessel sealing/cutting times, minimal bifurcated seal zones (BSZ), and high vessel burst pressures. Blood vessels were compressed to 400 μm thickness. A wide range of linear beam profiles (1-5 mm widths and 8-9.5 mm lengths), incident powers (20-200 W) and clinically relevant irradiation times (0.5-5.0 s) were simulated and peak seal and cut temperatures as well as thermal seal zones, ablation zones, and BSZ computed. A simplistic mathematical expression was used to estimate vessel burst pressures based on seal width. Optimal low-power parameters were: 24W/5s/8×2mm (sealing) and 24W/5s/8×1mm (cutting), yielding a BSZ of 0.4 mm, corresponding to experimental burst pressures of ~450 mmHg. Optimal medium-power parameters were: 90W/1s/9.5×3mm (sealing) and 90W/1s/9.5×1mm (cutting), yielding a BSZ of 0.9 mm for burst pressures of ~1300 mmHg. Simulated only optimal high-power parameters were: 200W/0.5s/9×3 mm (sealing) and 200W/0.5s/9×1mm (cutting), yielding a BSZ of 0.9 mm and extrapolated to predict a seal strength of ~1300 mmHg. All lasers produced seal zones between 0.4-1.5 mm, corresponding to high vessel burst pressures of 300-1300 mmHg (well above normal systolic blood pressure of 120 mmHg). Higher laser powers enable shorter sealing/cutting times and higher vessel strengths.

Sealing and Bisection of Blood Vessels using a 1470 nm Laser: Optical, Thermal, and Tissue Damage Simulations

A 1470-nm laser previously demonstrated faster sealing and cutting of blood vessels with lower thermal spread than radiofrequency and ultrasonic surgical devices. This study simulates laser sealing and cutting of vessels in a sequential two-step process, for low (< 25 W), medium (~ 100 W), and high (200 W) power lasers. Optical transport, heat transfer, and tissue damage simulations were conducted. The blood vessel was assumed to be compressed to 400 μm thickness, matching previous experimental studies. A wide range of linear beam profiles (1-5 mm widths and 8-9.5 mm lengths), incident powers (20-200 W) and irradiation times (0.5-5.0 s), were simulated. Peak seal and cut temperatures and bifurcated thermal seal zones were also simulated and compared with experimental results for model validation. Optimal low power laser parameters were: 24W/5s/8×2mm for sealing and 24W/5s/8×1mm for cutting, yielding thermal spread of 0.4 mm and corresponding to experimental vessel burst pressures (BP) of ~450 mmHg. Optimal medium-power laser parameters were: 90 W/1s/9.5×3mm for sealing and 90W/1s/9.5×1mm for cutting, yielding thermal spread of 0.9 mm for BP of ~1300 mmHg. Optimal high-power laser parameters were: 200W/0.5s/9×3mm for sealing and 200W/0.5s/9×1mm for cutting, yielding thermal spread of 0.9 mm and extrapolated to have BP of ~1300 mmHg. All lasers produced seal zones between 0.4-1.5 mm, correlating to high BP of 300-1300 mmHg. Higher laser powers enable shorter sealing and cutting times and higher vessel seal strengths.

Thermal Processes in Bile Ducts During Laparoscopic Cholecystectomy with Monopolar Instruments. Experimental Study Using Real-Time Intraluminal and Surface Thermography

Introduction. A significant rate of complications during laparoscopic cholecystectomy (LC) occurs due to thermal injury caused by monopolar electrosurgery (MES) equipment. Most of them manifest weeks and months after surgery with the common bile duct (CBD) and large duodenal papilla strictures, some in the early postoperative period with bile leaks. Objective. To study thermal processes occurring in the lumen and on the surface of the bile ducts during monopolar coagulation in a porcine model of LC. Methods. The temperature of the bile ducts was measured using instrumentation consisted of biliary stent with temperature sensors, which was inserted in the porcine CBD, signal amplifier, and current sense transformer. Surface temperature was measured with a scientific grade thermal camera. Cholecystectomy was performed using a standard "critical view of safety" (CVS) approach with 5 mm monopolar laparoscopic instruments. Results. Application of MES caused significant tissue heating. Lateral thermal spread and the rate of tissue heating depended on the duration of energy application and the initial tissue temperature. In 5 out of 6 experiments, the intraluminal temperature rose up to the critical threshold, and the exposure time ranged from 54 to 560 seconds. A sensor positioned at the papilla site was heated in all the experiments but still below the cell damage inducing threshold. The analysis of thermographic charts revealed the presence of the "current channeling" effect and the pedicle effect. Conclusion. There is a possibility of a direct and delayed thermal injury to the bile ducts during LC.

Optical coherence tomography for use in infrared laser sealing of blood vessels

Infrared lasers may provide faster sealing of vascular tissues with less collateral thermal damage and lower device temperatures than radiofrequency and ultrasonic devices currently used for surgery. Optical coherence tomography is tested to image native and thermally coagulated blood vessels, as a potential feedback system.

Novel Optical Linear Beam Shaping Designs for use in Laparoscopic Laser Sealing of Vascular Tissues. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020;2020:5049-5052. [PMID: 33019121 PMCID: PMC8311731 DOI: 10.1109/embc44109.2020.9176571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Suture ligation of vascular tissues is slow and skill intensive. Ultrasonic (US) and radiofrequency (RF) devices enable more rapid vascular tissue ligation to maintain hemostasis, than sutures and mechanical clips, which leave foreign objects in the body and require exchange of instruments. However, US and RF devices are limited by excessive collateral thermal damage to adjacent tissues, and high jaw temperatures that require a long time to cool. A novel alternative method using infrared (IR) laser energy is being developed for more rapid and precise sealing of vessels. This study describes design, modeling, and initial testing of several optical beam shaping geometries for integration into the standard jaws of a laparoscopic device. The objective was to transform the circular laser beam into a linear beam, for uniform, cross-irradiation and sealing of blood vessels. Cylindrical mirrors organized in a staircase geometry provided the best spatial beam profile.Clinical Relevance-This study explored several optical designs for potential integration into the standard jaws of a laparoscopic vessel sealing device, transforming a circular laser beam into a linear beam for sealing of vascular structures.

Sentinel Lymph Node Biopsy for Melanoma: Comparison of Lymphocele Rates by Surgical Technique

Lymphocele is a common wound complication of sentinel lymph node biopsy (SLNB). The surgical technique may play a key role in lymphocele formation. This study compared rates of postoperative lymphocele formation by different surgical techniques (Harmonic Scalpel [HS], LigaSure [LS], and traditional electrocautery with clips) after SLNB in the groin or axilla for the staging of clinically node-negative cutaneous melanoma. Patients were selected by convenience sample from a single-institution, single-surgeon, prospectively collected melanoma database over a 27-month period. One hundred fifty consecutive patients underwent SLNB, 70 with clips, 37 with HS, and 43 with LS. The median number of nodes removed was two and did not vary significantly between groups. Twenty-three lymphoceles occurred for an overall rate of 15 per cent; rates were 9.9 and 26.5 per cent for the axilla and groin, respectively. Sixteen (70%) were aspirated for size or symptoms; lymphoceles after groin SLNB were significantly (P = 0.03) more likely to require aspiration. Lymphocele rates for the clip, HS, and LS groups were 20.0, 18.9, and 4.7 per cent, respectively. The differences between the LS and other groups were statistically significant. Use of the LS may lead to lower lymphocele rates after groin and axillary SLNB compared with electrocautery and clips.

Prospective, multicenter, international phase 2 trial evaluating ultrasonic energy for pulmonary artery branch sealing in video-assisted thoracoscopic surgery lobectomy

OBJECTIVES

The study objectives were to evaluate the immediate, short-, and medium-term efficacy and safety of pulmonary artery branch sealing using an ultrasonic vessel-sealing device in minimally invasive anatomic lung resection.

METHODS

This study consists of a prospective, phase 2, multicenter, international clinical trial (clinicaltrials.gov: NCT02719717) that enrolled patients planned for video-assisted thoracoscopic surgery/robotic anatomic lung resection in 7 centers (United States, Canada, United Kingdom). Pulmonary artery branches of 7 mm or less were sealed and divided with an ultrasonic energy vessel-sealing device. The remainder of the lobectomy was performed according to surgeon preference. Intraoperative, in-hospital, and 30-day postoperative bleeding and complications were prospectively recorded.

RESULTS

A total of 150 patients with a minimum of 1 pulmonary artery branch sealed with an ultrasonic vessel-sealing device were prospectively enrolled in the trial. Resections included 139 lobectomies and 11 segmentectomies. A total of 424 pulmonary artery branches were divided: 239 with the ultrasonic vessel-sealing device, 181 with endostaplers, and 4 with endoscopic clips. The mean and median pulmonary artery diameters were 4.7 mm/5.0 mm, 10.3 mm/10.0 mm, and 6.5 mm/6.5 mm for each method, respectively. Three of the pulmonary artery branches divided with the ultrasonic vessel-sealing device (1.3%) and 4 pulmonary artery branches divided with endostaplers (2.2%) bled intraoperatively. Among the patients with seal failures, 1 patient required conversion to thoracotomy. There was no postoperative bleeding from divided pulmonary artery branches with either sealing method. There was no mortality at 30 days.

CONCLUSIONS

Pulmonary artery branch sealing with ultrasonic energy during video-assisted thoracoscopic surgery lobectomy is safe for vessels 7 mm or less. The use of an ultrasonic device is a reasonable sealing method for pulmonary artery branches 7 mm or less.

Evaluation and Comparison of Contemporary Energy-Based Surgical Vessel Sealing Devices

Introduction: We evaluated and compared five currently available energy-based vessel sealing devices to assess typical surgical metrics.

Methods: We tested Caiman 5 (C5), Harmonic Scalpel Ace Plus (HA), Harmonic Ace +7 (HA7), LigaSure (LS), and Enseal G2 (ES) on small (2–5 mm), medium (5.1–7 mm), and large (7.1–9 mm) vessels obtained from 15 Yorkshire pigs. Vessels were randomly sealed and transected. We recorded sealing and transection time, charring and carbonization, thermal spread, and bursting pressure (BP). Specimens were sent for histopathologic evaluation of seal quality and thermal spread.

Results: A total of 246 vessels were evaluated: 125 were arteries and 121 were veins. There was no difference in BPs for small size arteries. For medium arteries, C5 provided the highest BP (proximal and distal jaw), followed by HA7, ES, LS, and HA [1740, 1600, 1165, 1165, 981, and 571 mm Hg, respectively, HA<C5-D(<0.001); HA<C5-P(<0.001); HA<ES(0.002); HA<HA7(0.002); HA7<C5-P(0.026); ES<C5-P(0.026); LS<C5-P(0.001); LS<C5-D(0.014)]. For large arteries, C5 and LS provided highest BP followed by HA7, ES, and HA [1676, 530, 467, 467, and 254 mm Hg, respectively, C5<HA(<0.001); C5<HA7(0.006); C5<ES(0.006); C5<LS(0.012)]. There were no bursting pressure failures for C5, HA7, and LS up to 9 mm vessels. For medium and large size arteries, HA had bursting failure of 20% and 40%, respectively. The ES was significantly less efficient with small, medium, and large arteries with bursting failure rates of 10%, 40%, and 80%, respectively.

Conclusions: In this study, C5 outperformed all other devices. However, all of the devices provide a seal that was superphysiologic in that all burst pressures were >250 mm Hg.

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.

Lateral thermal spread induced by energy devices: a porcine model to evaluate the influence on the recurrent laryngeal nerve

BACKGROUND

Recurrent laryngeal nerve (RLN) paralysis is a frequently observed complication after esophagectomy, and thermal injury is considered to be one of the causes. The difference in the lateral thermal spread associated with the grasping range of various energy devices remains unknown.

METHODS

Ultrasonic devices (Harmonic® HD1000i and Sonicision™) and a vessel-sealing device (Ligasure™) were studied. We evaluated the temperature of these devices, the activation time required, and the thermal spread on porcine muscle when the devices were used with different grasping ranges (thermal spread study). In addition, we evaluated the influence of thermal spread by short grasping use of the energy devices on the viability of RLN in a live porcine model (NIM study).

RESULTS

In the thermal spread study, the temperature of the ultrasonic devices lowered as grasping range increased, whereas the highest temperature of Ligasure was observed when used with two-thirds grasping. The activation time of ultrasonic devices became longer as grasping range increased, whereas the grasping range did not influence the activation time of Ligasure. Thermal spreads 1 mm from the energy devices were unaffected by the grasping ranges. Although the temperature of the Ligasure was lower than that of the ultrasonic devices, thermal spread by Ligasure was significantly greater than that induced by the ultrasonic devices. In the NIM study, the activation of the Sonicision with one-third grasping range did not cause EMG changes at distances of up to 1 mm from the RLN, whereas applying Ligasure with a one-third grasping range 1 mm away from the RLN led to a critical result.

CONCLUSIONS

The grasping range did not influence the thermal spread induced by the energy devices. Ultrasonic devices may be safer in terms of lateral thermal spread to the RLN than Ligasure.

Laparoscopic ultrasonic dissectors: technology update by a review of literature

The evolution of minimally invasive surgery has brought forward the appearance of new advances in the course of the most recent couple of years and has introduced energy-based devices. The newest among them today are the ultrasonically activated devices, which are utilized with a great deal of components in-play, including ergonomics and financial aspects amid surgery. The methodology embraced was finding significant investigations through studies from PubMed, Medline and Google Scholar on current ultrasonic dissectors, which are Ethicon’s Harmonic Scalpel (ACE^®), Covidien’s Sonicision™ (SNC), Conmed’s SonoSurg^® (SS) and Olympus’s Thunderbeat^®, to describe their efficacy in terms of vessel sealing speed, vessel burst pressure, visibility, operation time and thermal speed. We found postmarketing evidence to determine which device exhibits the better performance. Animal studies showed that emissivity values and maximum temperatures for coagulation are similar among devices but maximum cutting temperatures are significantly different: ACE = 191.1°C, SNC = 227.1°C, SS = 184.8°C (p < 0.001). Cooling times are significantly different among devices: 35.7 s for ACE, 38.7 s for SNC and 27.4 s for SS (p < 0.001). Cooling times of passive jaws to reach 60°C after activation were also significantly different: 25.4 s for ACE, 5.7 s for SNC, and 15.4 s for SS (p < 0.001). The perfect device would unify brilliant hemostatic outcomes with visual sharpness while permitting none or insignificant thermal damage at the place of use.

Lateral thermal spread and recurrent laryngeal nerve paralysis after minimally invasive esophagectomy in bipolar vessel sealing and ultrasonic energy devices: a comparative study

BACKGROUND

This study aimed to compare the extent of lateral thermal spread of surrounding tissues after the use of advanced bipolar and ultrasonic coagulation and shearing devices. Association between recurrent laryngeal nerve paralysis (RLNP) and such devices was assessed in patients who underwent minimally invasive esophagectomy (MIE).

METHODS

LigaSure^™ (LS) and Sonicision^™ (SONIC) were used. In ex vivo experiments using the porcine muscle, blade temperature and tissue temperature were measured using a thermometer after the activation of both devices. For the clinical assessment, 46 consecutive patients who received MIE were retrospectively assessed.

RESULTS

The temperature generated at the blade of both devices increased with the activation time. The blade temperature of LS was significantly lower than that of SONIC (P < 0.001). The blade temperature of SONIC exceeded 100 °C after 3-s activation. The temperature of surrounding tissues after a single activation of the devices decreased with the tissue distance from activation blade. The temperatures of tissues at 1 and 2 mm away from the blade side of LS were significantly lower than those of SONIC (P = 0.001 and P < 0.001, respectively). The temperature of tissue 2 mm away from the blade side of LS increased 6.4 °C from the baseline temperature. Furthermore, the incidence of RLNP in the LS group was lower than that in the SONIC group (P = 0.044).

CONCLUSION

This study highlights the necessity of spatial and temporal recognition of the thermal spread of coagulation and shearing devices to reduce the thermal injuries following MIE.

Comparison of the Thermal Spread of Three Different Electrosurgical Generators on Rat Uterus: A Preliminary Experimental Study

BACKGROUND/AIMS

The objective of this study was to compare the depth and width of thermal spread caused on rat uterine tissue after application of 3 different electrosurgical generators.

METHODS

Alsa Excell 350 MCDSe (Unit A), Meditom DT-400P (Unit M), and ERBE Erbotom VIO 300 D (Unit E) electrosurgical units (ESUs) were used. The number of Wistar Hannover rats required to obtain valid results was 10. The primary objective of the study was to compare the 3 ESUs using the same instrument and the same waveform. The secondary objective of the study was to compare the differences between monopolar and bipolar systems of each ESU separately using the same waveform.

RESULTS

The thermal spread caused by each ESU using monopolar instruments with continuous and interrupted waveforms was significantly different. Among the 3 devices, Unit A caused the largest thermal uterine tissue spread. On the other hand, Unit E caused the most superficial thermal tissue spread, and the smallest thermal spread among all ESUs.

CONCLUSIONS

Surgeons should note that different ESUs used with the same power output might create different thermal effects especially in the monopolar configuration within the same waveform, for the same duration, and with the same instrument.

Vessel sealer and divider instrument temperature during laparoscopic ovariectomy in horses

OBJECTIVE

To determine the temperature of a vessel sealer and divider device during unilateral paralumbar laparoscopic ovariectomy in standing, sedated mares.

STUDY DESIGN

Prospective study.

ANIMALS

Fifteen healthy research mares.

METHODS

Healthy mares with normal ovarian palpation and ultrasonographic appearance were enrolled. Horses were restrained in standing stocks and sedated. A right or left paralumbar ovariectomy was performed with a laparoscopic portal and 2 instrument portals. Ovaries were excised with traumatic forceps and a blunt tip vessel sealer and divider. Temperatures of the vessel sealer and divider were recorded with a thermocouple device adhered to the tip of the instrument. Variables were reported as median and interquartile range (IQR).

RESULTS

Surgical time was 30 minutes (IQR, 25-32) including use of the vessel sealer and the divider for 4.1 minutes (IQR, 3.2-5.8). The tip of the instrument reached temperatures of 77°C (IQR, 72-85) during activation and 64°C (IQR, 61-67) at end cycle. The median increase in end-cycle instrument tip temperature per activation cycle was 2°C (IQR, -1-6). All mares returned to their intended use.

CONCLUSION

Despite the instrument temperatures observed during unilateral laparoscopic ovariectomy, surgical complications were minimal. The clinical relevance of the increase in instrument tip temperature of the vessel sealer and divider is presently unclear, but surgeons should use the instrument with caution, especially in close proximity to viscera. The increase in temperature observed at the tip of the vessel sealer and divider during unilateral ovariectomy could be associated with morbidity. The clinical relevance of instrument tip heating during other procedures, such as adhesiolysis and intestinal resection, is unknown and should be evaluated.

Phase 1 Trial Evaluating Safety of Pulmonary Artery Sealing With Ultrasonic Energy in VATS Lobectomy

BACKGROUND

Energy-sealing devices may be useful to divide small pulmonary arteries (PAs) during video-assisted thoracoscopic surgery (VATS) lobectomy. We evaluated the safety of PA branch sealing with an ultrasonic energy vessel-sealing device during VATS lobectomy.

METHODS

The study consisted of a phase 1 trial. Patients planned to undergo VATS lobectomy were prospectively enrolled. Target sample size was 20 patients. Branches of 7 mm or less were sealed and cut with an ultrasonic energy vessel-sealing device. The remainder of the lobectomy was performed in a standard fashion. Intraoperative, in-hospital, and 30-day postoperative bleeding were prospectively recorded.

RESULTS

Thirty-three patients were prospectively enrolled. Thirteen patients were not amenable to PA sealing with the vessel-sealing device because all PA branch diameters exceeded 7 mm (n = 10), conversion to thoracotomy (n = 2), and lobectomy not performed (n = 1). A minimum of one PA branch was sealed with the device in 20 patients. Fifty-eight PA branches were divided in 20 patients: 31 with ultrasonic device, 24 with endostaplers, 2 with clips, and 1 with sutures. The mean vessel diameter sealed with the device was 4 mm. Two patients were converted to thoracotomy (1 with PA injury during dissection, 1 with PA tumor invasion). No intraoperative or postoperative bleeding was related to ultrasonic PA branch sealing. No postoperative deaths occurred.

CONCLUSIONS

PA branch sealing for vessels 7 mm or less was safely achieved using an ultrasonic energy vessel-sealing device in VATS lobectomy. Large-scale, prospective, multi-institutional studies are necessary before widespread clinical application of energy for PA branch sealing in VATS lobectomy.

"Energy devices in gynecological laparoscopy - Archaic to modern era"

The introduction of newer vessel sealing systems has revolutionized techniques of hemostasis during laparoscopic surgery. These devices allow for rapid sequential tissue and vessel sealing, coagulation, and transection. Despite of widespread use of newer advanced bipolar and ultrasonic devices, monopolar and conventional bipolar electro-surgery still carry weightage due to wider range of tissue effect, dissection capabilities, cost effectiveness, and ease of availability. Here in we discussed different types of commonly available energy sources in terms of mechanism, efficacy and safety as thorough knowledge is utmost important for surgeon to choose appropriate instrument for surgical procedure.

Significance of a soft-coagulation system with monopolar electrode for hepatectomy: A retrospective two-institution study by propensity analysis

BACKGROUND

The VIO soft-coagulation system (VIO) with a monopolar electrode is a novel hemostatic device that provides hemostasis by superficial contact at the bleeding site without carbonization. Because heat injury remains a concern, surgical records and postoperative liver dysfunction were retrospectively evaluated in a cohort study.

METHODS

Between September 2010 and March 2016, 322 patients underwent hepatectomy in which hemostatic devices were used at two institutions. Surgical results with use of VIO at one institute (VIO group) were compared with those without use of VIO at a second institute (control group), and propensity analysis was performed.

RESULTS

In limited resection and segmentectomy or sectionectomy performed in the VIO group, the prevalence of liver cirrhosis was significantly higher and the operation time was significantly longer in comparison with the control group (p < 0.05). In all hepatectomies, postoperative levels of total bilirubin and aspartate or alanine transaminase tended to be increased and prothrombin activity tended to be lower in the VIO group in comparison with the control group (p < 0.05). The prevalence of hepatic failure in the VIO group was significantly higher in comparison with that in the control group (p < 0.05). In cases of segmentectomy or sectionectomy, blood loss was significantly increased in the VIO group in comparison with that in the control group (p < 0.05) Propensity score matching showed that although the surgical records and outcomes were not significantly different between the groups, postoperative liver dysfunction was significant in the VIO group in comparison with the control group (p < 0.05).

CONCLUSIONS

Mild postoperative hepatic thermal injury with VIO was confirmed, and therefore, surgeons should take care when using the VIO system to make frequent wide resected cuts on the surface of the liver.

Rapid sealing of porcine renal blood vessels, ex vivo, using a high power, 1470-nm laser, and laparoscopic prototype

Energy-based, radiofrequency (RF) and ultrasonic (US) devices currently provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternate energy modality for vessel sealing, capable of generating less collateral thermal damage. Previous studies demonstrated feasibility of sealing vessels in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for testing in open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices currently in surgical use was developed, and performance tests were conducted on porcine renal blood vessels, ex vivo. The 5-mm outer-diameter laparoscopic prototype featured a traditional Maryland jaw configuration that enables tissue manipulation and blunt dissection. Laser energy was delivered through a 550 - ? m -core-diameter optical fiber with side-delivery from the lower jaw and beam dimensions of 18 - mm ? length × 1.2 - mm ? width . The 1470-nm diode laser delivered 68 W with 3-s activation time, consistent with vessel seal times associated with RF and US-based devices. A total of 69 fresh porcine renal vessels with mean diameter of 3.3 ± 1.7 ?? mm were tested, ex vivo. Vessels smaller than 5-mm diameter were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038 ± 474 ?? mmHg . Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174 ± 221 ?? mmHg . Seal width, thermal damage zone, and thermal spread averaged 1.7 ± 0.8 , 3.4 ± 0.7 , and 1.0 ±

Comparison of the safety of electrotome, Harmonic scalpel, and LigaSure for management of thyroid surgery

BACKGROUND

Energy-based surgical devices, including electrotome, the Harmonic scalpel, and LigaSure, have been widely applied in thyroid surgery, although a comparison of their safety and efficacy has not been reported yet. In this study, we investigated the feasibility of using hemostatic energy-based surgical devices during thyroid surgery in a canine model.

METHODS

Twenty-four beagle dogs were randomly divided into the following groups: electrotome (30 kW), electrotome (15 kW), the Harmonic scalpel (output level 3), and LigaSure (middle gear). The hemostatic devices were applied on the thyroid surface for 3 seconds and then near the recurrent laryngeal nerve (RLN; distance of 5 mm, 3 mm, or 1 mm) for 3 seconds. Evoked electromyography (EMG) amplitudes were recorded by intraoperative neuromonitoring (IONM). Acute microstructural morphological damage to thyroid tissues and the RLN were evaluated immediately after the procedure by light and electron microscopy.

RESULTS

Electrotome caused a significant decrease in evoked EMG amplitudes when applied at a vertical distance of 1 mm from the RLN, both at 30 kW (1046 ± 404.3 μV vs 153 ± 245.5 μV; p < .001) and 15 kW (1197 ± 589.2 μV vs 986.3 ± 797.3 μV; p = .037), compared with those evoked under normal conditions. Furthermore, distinct acute microstructural morphological changes of the RLNs were observed by light and electron microscopy. However, no significant functional or histological changes were induced by the electrotome at a vertical distance of 5 mm or 3 mm from the RLN. The Harmonic scalpel and LigaSure induced neither marked changes in evoked EMG amplitudes when applied at vertical distances of 5 mm, 3 mm, or 1 mm (all p > .05) nor microstructural morphological changes in the RLNs. The electrotome (15 kW) caused more serious thermal damage to thyroid tissues than that caused by either the Harmonic scalpel or LigaSure (thermal damaged depth: 0.951 ± 0.061 vs 0.756 ± 0.074, p < .001; 0.951 ± 0.061 vs 0.724 ± 0.116, p < .001). Nevertheless, there were no differences between the Harmonic scalpel and LigaSure groups (p = .435).

CONCLUSION

LigaSure and the Harmonic scalpel might be safer than electrotome when used in thyroid operations. LigaSure generates less heat than the Harmonic scalpel and electrotome. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1078-1085, 2017.

A multi-physics model for ultrasonically activated soft tissue

A multi-physics model has been developed to investigate the effects of cellular level mechanisms on the thermomechanical response of ultrasonically activated soft tissue. Cellular level cavitation effects have been incorporated in the tissue level continuum model to accurately determine the thermodynamic states such as temperature and pressure. A viscoelastic material model is assumed for the macromechanical response of the tissue. The cavitation model based equation-of-state provides the additional pressure arising from evaporation of intracellular and cellular water by absorbing heat due to structural and viscoelastic heating in the tissue, and temperature to the continuum level thermomechanical model. The thermomechanical response of soft tissue is studied for the operational range of frequencies of oscillations and applied loads for typical ultrasonically activated surgical instruments. The model is shown to capture characteristics of ultrasonically activated soft tissue deformation and temperature evolution. At the cellular level, evaporation of water below the boiling temperature under ambient conditions is indicative of protein denaturation around the temperature threshold for coagulation of tissues. Further, with increasing operating frequency (or loading), the temperature rises faster leading to rapid evaporation of tissue cavity water, which may lead to accelerated protein denaturation and coagulation.

Infrared laser sealing of porcine vascular tissues using a 1,470 nm diode laser: Preliminary in vivo studies

INTRODUCTION

Infrared (IR) lasers are being explored as an alternative to radiofrequency (RF) and ultrasonic (US) devices for rapid hemostasis with minimal collateral zones of thermal damage and tissue necrosis. Previously, a 1,470 nm IR laser sealed and cut ex vivo porcine renal arteries of 1-8 mm diameter in 2 seconds, yielding burst pressures greater than 1,200 mmHg and thermal coagulation zones less than 3 mm. This preliminary study describes in vivo testing of a handheld laser probe in a porcine model.

METHODS

A handheld prototype with vessel/tissue clasping mechanism was tested on 73 blood vessels less than 6 mm diameter using 1,470 nm laser power of 35 W for 1-5 seconds. Device power settings, irradiation time, tissue type, vessel diameter, and histology sample number were recorded for each procedure. The probe was evaluated for hemostasis after sealing isolated and bundled arteriole/venous (A/V) vasculature of porcine abdomen and hind leg. Sealed vessel samples were collected for histological analysis of lateral thermal damage.

RESULTS

Hemostasis was achieved in 57 of 73 seals (78%). The probe consistently sealed vasculature in small bowel mesentery, mesometrium, and gastrosplenic and epiploic regions. Seal performance was less consistent on hind leg vasculature including saphenous arteries/bundles and femoral and iliac arteries. Collagen denaturation averaged 1.6 ± 0.9 mm in eight samples excised for histologic examination.

CONCLUSIONS

A handheld laser probe sealed porcine vessels, in vivo. Further probe development and laser parameter optimization is necessary before infrared lasers may be evaluated as an alternative to RF and US vessel sealing devices. Lasers Surg. Med. 49:366-371, 2017. © 2016 Wiley Periodicals, Inc.

Ultrasonically Activated Shears Reduce Blood Loss without Increasing Inflammatory Reactions in Open Distal Gastrectomy for Cancer: A Randomized Controlled Study

BACKGROUND

Previous studies regarding ultrasonically activated shears (UAS) were performed without controlled surgical procedures or consideration of potential thermal injury due to high temperature of active blade of UAS. The purpose of this study was to evaluate the efficacy and safety of UAS through a comparison with conventional monopolar electrocautery (CME) in open distal gastrectomy for gastric cancer.

METHODS

From October 2011 to November 2012, 56 gastric cancer patients eligible for open distal gastrectomy were randomized into UAS or CME groups. Primary endpoints were estimated blood loss (EBL) during surgery and amount of drainage through the fifth postoperative day. Secondary endpoints were operation time, length of hospital stay, postoperative morbidity, changes in cytokine levels in serum, peritoneal irrigation saline, and peritoneal drainage, and inflammatory markers of serum. (Registration-number of ClinicalTrials.gov: NCT01971775).

RESULTS

EBL was lower in the UAS group than that in the CME group (339.8 ± 201.2 vs. 428.6 ± 165.8 mL, p = 0.021). However, the amount of postoperative drainage was not significantly different between the two groups. Although the complication rate was not different between the two groups, there were three cases of intra-abdominal bleeding requiring transfusion only in the CME group. Inflammatory markers from the cytokine assays and serum laboratory tests showed no significant differences between the two groups.

CONCLUSIONS

UAS reduced EBL without increasing inflammatory reactions.

Safety of LigaSure in recurrent laryngeal nerve dissection-porcine model using continuous monitoring

OBJECTIVES/HYPOTHESIS

This study investigated recurrent laryngeal nerve (RLN) real-time electromyography (EMG) data to define optimal safety parameters of the LigaSure Small Jaw (LSJ) instrument during thyroidectomy.

STUDY DESIGN

Prospective animal model.

METHODS

Dynamic EMG tracings were recorded from 32 RLNs (16 piglets) during various applications of LSJ around using continuous electrophysiologic monitoring. At varying distances from the RLN, the LSJ was activated (activation study). The LSJ was also applied to the RLN at timed intervals after activation and after a cooling maneuver through placement on the sternocleidomastoid muscle (cooling study).

RESULTS

In the activation study, there was no adverse EMG event at 2 to 5 mm distance (16 RLNs, 96 tests). In the cooling study, there was no adverse EMG event after 2-second cooling time (16 RLNs, 96 tests) or after the LSJ cooling maneuver on the surrounding muscle before reaching the RLNs (8 RLNs, 24 tests).

CONCLUSION

Based on EMG functional assessment, the safe distance for LSJ activation was 2 mm. Further LSJ-RLN contact was safe if the LSJ was cooled for more than 2 seconds or cooled by touch muscle maneuver. The LSJ should be used with these distance and time parameters in mind to avoid RLN injury.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 127:1724-1729, 2017.

A comparison of laparoscopic energy devices on charges in thermal power after application to porcine mesentery

INTRODUCTION

Advances in energy devices have played a major role in the rapid expansion of laparoscopic surgery. However, complications due to these energy devices are occasionally reported, and if the characteristics of these devices are not well understood, serious complications may occur. This study evaluated various typical energy devices and measured temperature rises in the adjacent tissue and in the devices themselves.

EQUIPMENT AND METHODS

We used the following 7 types of energy devices: AutoSonix (AU), SonoSurg (SS), Harmonic Scalpel (HS), LigaSure Atlas (LA), LigaSure Dolphin Tip (LD), monopolar diathermy (Mono), and bipolar scissors (Bi). Laparoscopy was performed under general anesthesia in pigs, and the mesentery was dissected using each energy device. Tissue temperature at a distance of 1 mm from the energy device blade before and after dissection was measured. Temperature of the device blade both before and after dissection, time required for dissection, and interval until the temperature fell to 100°C, 75°C, and 50°C were documented.

RESULTS

Temperature of the surrounding tissue using each device rose the most with the Mono (50.5±8.0°C) and the least with the HS in full mode (6.2±0.7°C). Device temperature itself rose the highest with the AU in full mode (318.2±49.6°C), and the least with the Bi (61.9±4.8°C). All ultrasonic coagulation and cutting devices (AU, SS, and HS) had device temperatures increase up to ≥100°C, and even at 8 seconds after completing dissection, temperatures remained at ≥100°C.

CONCLUSIONS

Because the adjacent tissue temperature peaked with the Mono, cautious use near the intestine and blood vessels is necessary. In addition, the active blades of all ultrasonic coagulation and cutting devices, regardless of model, developed high temperatures exceeding 100°C. Therefore, an adequate cooling period after using these devices is therefore necessary between applications.

Surgical Efficacy Among Laparoscopic Ultrasonic Dissectors: Are We Advancing Safely? A Review of Literature

The specialty of laparoscopy has evolved with the advent of new technologies over the last few years. Energy-based devices and Ultrasonic dissectors are used with a lot of factors in play-including ergonomics and economics during surgery. Here an attempt is based to review the surgical efficacy and safety of these dissectors with importance to plume production and lateral thermal damage. The factors contributing to adversities to the dissectors are also to be noted. The strategy adopted was aimed at finding relevant studies from PubMed from 1995 to 2014. The basic principle of plume production and thermal damage are studied in this review. Factors contributing to the same that can lead to adversities during laparoscopic surgeries are identified. Summarizing key points that increase lateral thermal damage and plume production amongst different ultrasonic shears and suggesting a technique to identify the right balance between the existing dissectors was possible. The RF Device and USS are both useful and widely used and are more safer than monopolar devices. RF Device is considerably slower than USS, as it cannot achieve coagulation and cutting at the same time. Although USS definitely improvises dissection and has less thermal injury than RF Device, the clinical implications in balancing dissection efficacy with hemostasis need to be investigated further. The ideal haemostatic energy-based shear device would be one with excellent hemostatic results and visual acuity while allowing none or minimal thermal energy escape at the point of application. In our current setting, a combined use of both RF and USS device usage as applied in the particular situations has potential.

Efficacy of a half-grip technique using a fine tip LigaSure™, Dolphin Tip Sealer/Divider, on liver dissection in swine model

BACKGROUND

Recently, a lot of energy devices in the surgical field, especially in the liver surgery, have been developed, and a fine tip LigaSure™, Dolphin Tip Sealer/Divider (DT-SD) also has been used frequently to dissect liver parenchyma as well as ultrasonically activated device (USAD). However, the utility of this instrument for liver dissection (LD) is still unknown. Moreover, to reduce bleeding during LD, a half-grip technique (HGT) was contrived. We herein report an experimental study in swine model to evaluate the feasibility and effectiveness of HGT using DT-SD for LD.

METHODS

The swine model experiment was carried out under general anesthesia by veterinarians. LD was performed repeatedly by DT-SD with the HGT (Group A, n = 6), or the conventional clamp-crush technique (CCT) (Group B, n = 6), and by variable mode USAD (Group C, n = 6). The dissection length and depth (cm) as well as bleeding volume (g) were measured carefully, and the dissection area (cm(2)) and speed (cm(2)/min) were calculated precisely. Histological examinations of the dissection surfaces were also executed. Mann-Whitney's U test was used for Statistical analyses with variance at a significance level of 0.05.

RESULTS

Among the three groups, the three averages of dissection lengths were unexpectedly equalized to 8.3 cm. The dissection area (cm(2)) was 9.9 ± 5.1 in Group A, 9.8 ± 4.7 in Group B, and 9.9 ± 4.5 in Group C. The mean blood loss during LD was 10.6 ± 14.8 g in Group A, 41.4 ± 39.2 g in Group B, and 34.3 ± 39.2 g in Group C. For Group A, the bleeding rate was the least, 0.9 ± 1.0 g/cm(2), and the average depth of coagulation was the thickest, 1.47 ± 0.29 mm, among the three groups (p < 0.05). The dissection speed in Group A (1.3 ± 0.3 cm(2)/min) was slower, than that in Group C (p < 0.05).

CONCLUSIONS

This report indicates firstly that the HGT using DT-SD bring the least blood loss when compared with CCT or USAD. Although the HGT is feasible and useful for LD, to popularize the HGT, further clinical studies will be needed.

Comparison of a New High-Frequency Electric Welding System for Intestinal Closure with Hand-Sewn In Vivo Pig Model

BACKGROUND

Various surgical small intestinal anastomosis methods are in current use, but improvements are always desired. Thus, we compared the feasibility, effectiveness, and safety of a new high-frequency electric welding (HFEW) system for sealing the small bowel versus a hand-sewn in vivo pig model.

MATERIALS AND METHODS

The 96 bowel segments of three pigs were randomized to be sutured either by the HFEW-300 PATONMED device (E.O. Paton Electric Welding Institute of the National Academy of Sciences of Ukraine, Kiev, Ukraine) or hand-sewn, and mucosa-to-mucosa fusions were subjected in vivo testing in the pigs. Bursting pressures, suture time, thermal damage, and the temperature of sealed ends were measured.

RESULTS

Segments that had been treated with a hand-sutured ligature or double-sealed with HFEW were compared. Burst pressure was significantly higher in the hand-sutured group than in the HFEW group (136.2 mm Hg versus 75.8 mm Hg, P<.01). All 48 pig small bowels closed by the HFEW-300 generator showed a success rate of 100.0%. The closing time in the HFEW group was significantly shorter (P<.01). The pathological changes of the closed ends were mainly presented as acute thermal- and pressure-induced injuries.

CONCLUSIONS

Outcomes of the current in vivo study suggest that HFEW is an effective and safe method for ligation of the small bowel in pigs.

Clinical use of a cordless laparoscopic ultrasonic device

OBJECTIVE

On April 25, 2012, the first laparoscopic cordless ultrasonic device (Sonicision, Covidien, Mansfield, Massachusetts) was used in a clinical setting. We describe our initial experience.

METHODS

The cordless device is assembled with a reusable battery and generator on a base hand-piece. It has a minimum and maximum power setting controlled by a single trigger for both coagulation and cutting. A laparoscopic radical nephrectomy was performed on a 56-year-old man with a 7-cm right renal mass. A laparoscopic pelvic lymphadenectomy was performed in a 51-year-old man with high-risk prostate cancer. Data on surgical team satisfaction, operative time, number of activations, and times the laparoscope was removed as a result of plume were collected.

RESULTS

The surgical technician successfully assembled the device at the beginning of the cases with verbal instructions from the surgeon. Operative time for nephrectomy was 77 minutes, with 143 total activations (minimum = 86, maximum = 57). The operative time for the pelvic lymphadenectomy was 27 minutes, with 38 total activations (minimum = 27, maximum = 11). One battery was used in each case. The laparoscope was removed twice during the nephrectomy and once during the lymphadenectomy. Surgical staff satisfaction survey results revealed easier and faster assembly, more space in the operating room, ergonomic handle, and comparable cutting/coagulation, weight, and plume generation with other devices (Table 1). [Table: see text].

CONCLUSION

The first clinical application of the pioneering cordless dissector was successfully performed, resulting in surgeons' perceptions of comparable results with other devices of easier and safer use and faster assembly.

Clinical use of a cordless laparoscopic ultrasonic device

Objective:

On April 25, 2012, the first laparoscopic cordless ultrasonic device (Sonicision, Covidien, Mansfield, Massachusetts) was used in a clinical setting. We describe our initial experience.

Methods:

The cordless device is assembled with a reusable battery and generator on a base hand-piece. It has a minimum and maximum power setting controlled by a single trigger for both coagulation and cutting. A laparoscopic radical nephrectomy was performed on a 56-year-old man with a 7-cm right renal mass. A laparoscopic pelvic lymphadenectomy was performed in a 51-year-old man with high-risk prostate cancer. Data on surgical team satisfaction, operative time, number of activations, and times the laparoscope was removed as a result of plume were collected.

Results:

The surgical technician successfully assembled the device at the beginning of the cases with verbal instructions from the surgeon. Operative time for nephrectomy was 77 minutes, with 143 total activations (minimum = 86, maximum = 57). The operative time for the pelvic lymphadenectomy was 27 minutes, with 38 total activations (minimum = 27, maximum = 11). One battery was used in each case. The laparoscope was removed twice during the nephrectomy and once during the lymphadenectomy. Surgical staff satisfaction survey results revealed easier and faster assembly, more space in the operating room, ergonomic handle, and comparable cutting/coagulation, weight, and plume generation with other devices (Table 1).

Conclusion:

The first clinical application of the pioneering cordless dissector was successfully performed, resulting in surgeons' perceptions of comparable results with other devices of easier and safer use and faster assembly.