Comparison of blood vessel sealing among new electrosurgical and ultrasonic devices

Microwave Scissors-Based Sutureless Laparoscopic Partial Nephrectomy Versus Conventional Open Partial Nephrectomy in a Porcine Model: Usefulness and Complications

BACKGROUND

This study aimed to compare the benefits and safety of microwave scissors-based sutureless laparoscopic partial nephrectomy (MSLPN) with those of conventional open partial nephrectomy (cOPN).

METHODS

Each kidney in nine pigs underwent MSLPN using microwave scissors (MWS) via transperitoneal laparoscopy or cOPN via retroperitoneal open laparotomy. The kidney's lower and upper poles were resected under temporary hilar-clamping. The renal calyces exposed during renal resections were sealed and transected using MWS in MSLPN and were sutured in cOPN. For MWS, the generator's power output was 60 W. Data on procedure time (PT), ischemic time (IT), blood loss (BL), normal nephron loss (NNL), and extravasation during retrograde pyelogram were compared between the two techniques.

RESULTS

The authors successfully performed 22 MSLPNs and 10 cOPNs. Compared with cOPN, MSLPN was associated with significantly lower PT (median, 9.2 vs 13.0 min; p = 0.026), IT (median, 5.9 vs 9.0 min; p < 0.001), BL (median, 14.4 vs 38.3 mL; p = 0.043), and NNL (median, 7.6 vs 9.4 mm; p = 0.004). However, the extravasation rate was higher in the MSLPN group than in the cOPN group (54.5 % [n = 12] vs 30.0 % [n = 3]), albeit without a significant difference (p = 0.265). Pelvic stenosis occurred in one MSLPN procedure that involved deep lower pole resection near the kidney hilum.

CONCLUSIONS

The study data show that MSLPN can improve intraoperative outcomes while reducing technical demands for selected patients with non-hilar-localized renal tumors. However, renal calyces, if violated, should be additionally sutured to prevent urine leakage.

Assessing the influence of parameters on tissue welding in small bowel end-to-end anastomosis in vitro and in vivo

BACKGROUND

The use of high-frequency electric welding technology for intestinal end-to-end anastomosis holds significant promise. Past studies have focused on in vitro, and the safety and efficacy of this technology is uncertain, severely limiting the clinical application of this technology. This study investigates the impact of compression pressure, energy dosage, and duration on anastomotic quality using a homemade anastomosis device in both in vitro and in vivo settings.

METHODS

Two hundred eighty intestines and 5 experimental pigs were used for in vitro and in vivo experiments, respectively. The in vitro experiments were conducted to study the effects of initial pressure (50-400 kpa), voltage (40-60 V), and time (10-20 s) on burst pressure, breaking strength, thermal damage, and histopathological microstructure of the anastomosis. Optimal parameters were then inlaid into a homemade anastomosis and used for in vivo experiments to study the postoperative porcine survival rate and the pathological structure of the tissues at the anastomosis and the characteristics of the collagen fibers.

RESULTS

The anastomotic strength was highest when the compression pressure was 250 kPa, the voltage was 60 V, and the time was 15 s. The degree of thermal damage to the surrounding tissues was the lowest. The experimental pigs had no adverse reactions after the operation, and the survival rate was 100%. 30 days after the operation, the surgical site healed well, and the tissues at the anastomosis changed from immediate adhesions to permanent connections.

CONCLUSION

High-frequency electric welding technology has a certain degree of safety and effectiveness. It has the potential to replace the stapler anastomosis in future and become the next generation of new anastomosis device.

Advanced bipolar vessel sealing devices vs conventional bipolar energy in minimally invasive hysterectomy: a systematic review and meta-analysis

PURPOSE

To compare conventional bipolar electrosurgery with advanced bipolar vessel sealing (ABVS) devices for total laparoscopic hysterectomy (TLH).

METHODS

A systematic review was conducted by searching Scopus, PubMed/MEDLINE, ScienceDirect, and Cochrane Library from January 1989 to November 2021. We identified all studies comparing ABVS devices with conventional bipolar electrosurgery in TLH and reporting at least one of the following outcomes: total blood loss, total operative time, hospital stay, perioperative complications, or costs. Meta-analysis was conducted with a random effect model reporting pooled mean differences and odds ratios (ORs) with related 95% confidence intervals (CIs).

RESULTS

Two randomized controlled trials and two retrospective studies encompassing 314 patients were included out of 615 manuscripts. The pooled estimated total blood loss in the ABVS devices group was lower than conventional bipolar electrosurgery of 39 mL (95% CI - 65.8 to - 12.6 mL; p = .004). The use of ABVS devices significantly reduced the total operative time by 8 min (95% CI - 16.7 to - 0.8 min; p = .033). Hospital stay length did not differ between the two groups, and a comparable overall surgical complication rate was observed [OR of 0.9 (95% CI 0.256 - 3.200; p = .878].

CONCLUSIONS

High-quality evidence comparing ABVS devices with conventional bipolar electrosurgery for TLH is lacking. ABVS devices were associated with reduced total blood loss and operative time; however, observed differences seem clinically irrelevant. Further research is required to clarify the advantages of ABVS devices over conventional bipolar electrosurgery and to identify cases that may benefit more from their use.

Harmonic Scalpel Versus Monopolar Electrotome in Endoscopic-Assisted Transaxillary Dual-Plane Augmentation Mammaplasty: A Retrospective Study in 122 Patients

BACKGROUND

The transaxillary approach of breast augmentation is the most popular method in Asia, but longer period of recovery was observed in spite of the assistance of endoscope.

OBJECTIVES

Introducing the ultrasonic dissection devices might be a solution to minimizing tisue damage thus relieving pain and shortening the period of recovery.

METHOD

Between March 2020 and September 2022, we retrospectively reviewed the cases of 122 patients underwent endoscopic augmentation mammoplasty via the transaxillary approach using either the monopolar electrotome (ME) alone or assisted with Harmonic Scalpel (HS) in defining the retropectoral pocket and severing the pectoralis major muscle.

RESULT

The total drainage volume was significantly lower in the HS group than ME group (74.33 ± 48.81 vs. 180.30 ± 125.10 mL; p < 0.0001). VAS score of the first 24 hour after surgery of the ME group was significantly higher than that of the HS group (6.10 ± 1.27 vs. 2.88 ± 1.29, p < 0.0001). Operation time in HS group was reduced compared to ME group (113.1 ± 14.46 mins vs. 131.3 ± 35.51 mins, p < 0.001). The duration of drainage placement (1.08 ± 0.27 vs. 2.72 ± 1.18 days) and hospital stay after surgery (3.08 ± 0.42 vs. 5.64 ± 2.78 days; p < 0.0001) were largely reduced in HS group.

CONCLUSION

The assistance of Harmonic Scalpel significantly reduced total postoperative drainage, relieved pain and shortened operation time, length of drainage placement and hospital stay compared to using monopolar electrotome alone in endoscopic-assisted transaxillary dual-plane augmentation mammaplasty.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of two advanced bipolar tissue sealer/dividers for laparoscopic ovariectomy in dogs: articulating enseal G2 versus Ligasure Maryland device

BACKGROUND

Advanced bipolar tissue sealer/dividers provide the most reliable and efficient means of tissue dissection and blood vessel sealing in laparoscopic surgery and the techniques are continuously improved. In veterinary practice, cost-effectiveness is of major impact, leading to re-use of instruments designed and sold for single use. Two high-end devices were evaluated and compared in a highly standardized laparoscopic ovariectomy procedure in dogs: The new generation Ligasure Maryland Sealer/Divider (LMSD) with improved atraumatic curved jaw shape for delicate tissue handling and dissection and non-stick nanocoating, and the new-generation Articulating Enseal G2 (AENG2) with several proclaimed features improving surgical performance, including articulation of the forceps tip; improved tissue compression during sealing; unique offset electrode configuration; and specific nanoparticle coating minimizing thermal spread and tissue sticking. Twenty-one client-owned dogs admitted for elective laparoscopic ovariectomy were randomly assigned to one of two groups: ovariectomy using AENG2 on the left ovary and LMSD in the right ovary or vice-versa. Procedural video recordings were used to assess ovarian ligament fat score, smoke formation, occurrence of bleeding, and excision duration. Excised tissues were examined histopathologically and collateral thermal damage was scored in three anatomic zones: suspensory ligament, vascular pedicle, and uterine junction. Tissue sealers were used repeatedly following standardized cleaning protocol with instrument washing machine and ethylene oxide gas sterilization and the number of uses until device failure was recorded.

RESULTS

Excision times were significantly increased for AENG2 (median 01:35 min) compared to LMSD (median 01:00 min). Minor hemorrhage from incomplete sealing occurred in 3 sites in 2 patients (2x AENG2, 1x LMSD) and was not significantly different between groups. Smoke production as scored on videos and thermal tissue damage scores on histopathology also did not differ between AENG2 and LMSD. Both vessel sealers could be re-used repeatedly.

CONCLUSION

AENG2 provides a good alternative to LMSD in laparoscopic ovariectomy, with only minor differences in measured variables. Subjectively, the articulating feature of AENG2 did not improve surgical performance in laparoscopic ovariectomy and the use of LMSD appeared more straight-forward for this specific procedure. However, differences in operating these devices may be subject to personal preference.

A new bipolar device for sealing and cutting: ex and in vivo studies for performance evaluation

INTRODUCTION

A novel multipurpose bipolar radiofrequency instrument, the Erbe Dissector (EDS), which simultaneously seals and cuts tissue, was developed. Ex vivo sealing rate and time, burst pressure, jaw temperature and thermal spread were studied in porcine renal arteries.

MATERIAL AND METHODS

In vivo, 13 surgical tasks were performed in two pigs: beside sealing rate and time, overall performance in sharp and blunt dissection, tissue sticking, hemostasis, precision, etc., were evaluated by four surgeons compared with ENSEAL G2 (EG2) using surveys on a Likert scale (1 = very poor; 5 = very good).

RESULTS

Ex vivo, the EDS sealing rate was 91.7% (33/36 arteries) at an average sealing time of 2.1 s (range 1.7-2.8) and a burst pressure of 1040 ± 350 mmHg. The maximum jaw temperature was 87 ± 4 °C and the mean lateral thermal spread was 0.8 ± 0.2 mm. In vivo, the sealing rate for arteries and veins was 92.6% (50/54) and the median seal and cut time was 1.6 s (range: 1.3-2.9). The average EDS performance score across all tasks was 4.4 ± 0.6 Likert points. For five shared tasks, EDS was better than EG2 (4.4 ± 0.5 versus 3.4 ± 0.6 Likert points; p = 0.016).

CONCLUSIONS

EDS seals and cuts arteries and veins rapidly with good safety and user-friendliness.

Characteristics of Collagen Changes in Small Intestine Anastomoses Induced by High-Frequency Electric Field Welding

High-frequency electric field welding-induced tissue fusion has been explored as an advanced surgical method for intestinal anastomoses; however, intrinsic mechanisms remain unclear. The aim of this study was to investigate microcosmic changes of collagen within the fusion area, with various parameters. Ex vivo small intestine was fused with mucosa-mucosa. Four levels of compressive pressure (100 kPa, 150 kPa, 200 kPa, 250 kPa) were applied for 10 s in order to fuse the colons under a power level of 140 W. Then, collagen fibers of the fusion area were examined by fibrillar collagen alignment and TEM. Three levels of power (90 W, 110 W, 140 W) and three levels of time (5 s, 10 s, 20 s) were applied in order to fuse colons at 250 kPa, and then collagen within the fusion area was examined by Raman spectroscopy. Fibrillar collagen alignment analysis showed that with the increase in compression pressure, alignment of the collagen in the fusion area gradually increased, and the arrangement of collagen fibers tended to be consistent, which was conducive to the adhesion of collagen fibers. TEM showed that pressure changed the distribution and morphology of collagen fibers. Raman spectroscopy showed that increased power and time within a certain range contributed to collagen cross linking. Peak positions of amide I band and amide III band changed. These results suggested that higher power and a longer amount of time resulted in a decrease in non-reducible cross links and an increase in reducible cross links. Compression pressure, power, and time can affect the state of collagen, but the mechanisms are different. Compressive pressure affected the state of collagen by changing its orientation; power and time denatured collagen by increasing temperature and improved the reducible cross linking of collagen to promote tissue fusion.

Advances and safe use of energy devices in lung cancer surgery

Objectives

A clear understanding of energy devices would help achieve high effectiveness and safety and guide the selection of devices. The present review aimed to elucidate the efficacy and adverse events of energy devices in lung cancer to guide the selection of appropriate devices depending on the situation.

Methods

Four major databases were searched electronically for relevant articles published until 16 April 2021. The reference lists of the identified papers were examined. We excluded (1) irrelevant studies, (2) manuscripts published in languages other than English and Japanese, (3) duplicates, and (4) studies for which the full text was not available in the databases. The results and key information obtained were summarized by means of a narrative approach.

Results

A total of 78 papers were included in the review and these were categorized according to the main topic of investigation as follows: (1) electrosurgery-related injuries, (2) fundamentals of electrosurgery, (3) monopolar devices, (4) bipolar electrosurgical devices, (5) ultrasonic energy devices, (6) energy devices in lung cancer surgery, (7) operating room fire risks, and (8) basic principles of surgery.

Conclusions

Understanding energy devices could help us use them in a more effective and safer manner. Knowledge of their selection criteria (suitability), merits, risks, and safety precautions relevant to each process of lung cancer surgery could guide appropriate selection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11748-022-01775-w.

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.

Theoretical and Empirical Verification of Electrical Impedance Matching Method for High-Power Transducers

In our prior study, a systematic approach was used to devise Langevin transducers for high-power applications where the energy efficiency was not considered in the design criteria. In this paper, the impedance matching methods are thus proposed to evaluate what matching topology is appropriate for their use. Both the series inductor scheme and low pass filter composed of a series inductor and shunt capacitor are examined as matching circuits. According to MATLAB simulation, the resonance frequency is seen at 36.79 kHz due to a series L circuit, and its associated impedance is reduced by 70.45% from that of its non-matching condition. The measured resonance frequency is 36.77 kHz and the corresponding impedance is decreased by 59.52%. Furthermore, the acoustic pressure is measured to determine the effect of the matching circuit on the transducer’s actual behavior. The transducer with a series L circuit shows more efficient matching results, 2.28 kPa of positive acoustic pressure is emitted without matching and 3.35 kPa is emitted with a series L element, respectively. As a result, this study demonstrates how to evaluate the influence of matching circuits by using our customized approach rather than commercial SPICE programs, as well as how to experimentally verify the acoustic behavior of high-power Langevin transducers.

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.

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.

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.

Comparison of surgical outcomes using Gyrus PKS™ vs LigaSure™ in total laparoscopic hysterectomy: A randomised controlled trial

BACKGROUND

Advanced vessel sealing devices are widely used in laparoscopic surgery. However, there remains a lack of adequately powered trials comparing laparoscopic advanced vessel sealing devices in the clinical setting, especially in gynaecology.

AIMS

This single-blinded randomised controlled trial aims to compare the surgical outcomes of total laparoscopic hysterectomy (TLH) using either the Gyrus PKS™ LYONS dissecting forceps or the LigaSure™ Maryland jaw vessel sealer/divider.

MATERIALS AND METHODS

Women who required TLHs for benign indications were randomised to having their surgeries performed using either Gyrus PKS™ or LigaSure™. Time to haemostasis (from initial skin incision to detachment of the uterus with secured haemostasis) was the primary outcome; a 20% difference in time was considered clinically significant. Secondary outcomes measured were intra-operative blood loss, complications, conversions, post-operative analgesia use, and length of stay. This study was registered with the Australia New Zealand Clinical Trials Registry ACTRN12615000639516.

RESULTS

Sixty-four women were included in the study - 33 and 31 in the Gyrus PKS™ and LigaSure™ arms, respectively. TLHs performed by LigaSure™ had statistically significantly shorter time to haemostasis compared to Gyrus PKS™ by 10.6 min (95% CI 1.3-2.0, P = 0.03). There were no differences in any of the other secondary outcomes measured.

CONCLUSIONS

This trial suggests there is no difference between using either device. TLHs performed using LigaSure™ have statistically significantly shorter time to haemostasis than those using Gyrus PKS™; however, the difference is not considered clinically significant as it was only 14.2%. No other differences in surgical outcomes were detected.

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.

Safety and effectiveness of a novel generator algorithm for bipolar vessel sealing: a randomised controlled chronic animal study

BACKGROUND

Electrosurgical vessel sealers are gradually replacing conventional techniques such as ligation and clipping. Algorithms that control electrosurgical units (ESU), known as modes, are important for applications in different surgical disciplines. This chronic porcine animal study aimed to evaluate the safety and effectiveness of the novel thermoSEAL electrosurgical vessel sealing mode (TSM). The BiClamp® mode (BCM) of the renowned VIO® 300 D ESU served as control. BCM has been widely available since 2002 and has since been successfully used in many surgical disciplines. The TSM, for the novel VIO® 3 ESU, was developed to reduce sealing time and/or thermal lateral spread adjacent to the seal while maintaining clinical success rates. The primary aim of this study was to investigate the long-term and intraoperative seal quality of TSM.

METHODS

The BiCision® device was used for vessel sealing with TSM and BCM in ten German Landrace pigs which underwent splenectomy and unilateral nephrectomy during the first intervention of the study. The seals were cut with the BiCision® knife. Ninety-nine arteries, veins and vascular bundles were chronically sealed for 5 or 21 days. Thereafter, during the second and terminal intervention of the study, 97 additional arteries and veins were sealed. The carotid arteries were used for histological evaluation of thermal spread.

RESULTS

After each survival period, no long-term complications occurred with either mode. The intraoperative seal failure rates, i.e. vessel leaking or residual blood flow after the first sealing activation, were 2% with TSM versus 6% with BCM (p = 0.28). The sealing time was significantly shorter with TSM (3.5 ± 0.69 s vs. 7.3 ± 1.3 s, p < 0.0001). The thermal spread and burst pressure of arteries sealed with both modes were similar (p = 0.18 and p = 0.61) and corresponded to the histological evaluation. The measured tissue sticking parameter was rare with both modes (p = 0.33). Tissue charring did not occur. Regarding the cut quality, 97% of the seals were severed in the first and 3% in the second attempt (both with TSM and BCM).

CONCLUSIONS

The novel TSM seals blood vessels twice as fast as the BCM while maintaining excellent tissue effect and clinical success rates.

TRIAL REGISTRATION

Not applicable.

Enhanced photothermal hemostasis using dual wavelengths in an in vivo leporine kidney model

The current study investigated the hemostatic effect of dual wavelengths on in vivo leporine kidney tissue using 532-nm and 980-nm laser systems. Three irradiation modes, 532 nm, 980 nm, and dual (532 and 980 nm) modes, were compared to test non-contact photothermal hemostasis on 36 bleeders in the kidney models. Each bleeder was flushed with saline during the irradiation. The dual mode achieved complete hemostasis more rapidly than the single modes (4.0 ± 1.4 s for dual vs. no hemostasis for 532 nm and 10.0 ± 1.3 s for 980 nm; p < 0.001). Application of 60 W from the dual wavelengths expanded the surface area of the thermal lesion (up to 60%). In vivo dual-wavelength irradiation achieved more rapid and complete hemostasis with ∼2 mm coagulation depth than the single-wavelength irradiation.

Less Pain and Reduced Risk of Early Postoperative Ileus After Clipless Versus Conventional Laparoscopic Appendectomy

Laparoscopic appendectomy (LA) is perceived as a procedure requiring a short hospital stay; however, some patients require prolonged hospitalization because of postoperative ileus and pain; therefore, we introduced clipless LA, using only an ultrasonic energy device only for coagulation. A total of 1013 patients (clipless LA; n=290 and conventional LA; n=723) who underwent LA at our hospital between January 2015 and February 2018 were analyzed. The mean operative time was shorter (P<0.001), and postoperative pain score at 24 hours was lower (P<0.001) for clipless than for conventional LA. There were no significant differences in postoperative complications, except with regard to early postoperative ileus (clipless LA; 18.1% vs. conventional LA; 31.6%, P=0.025), and the operative method had significantly influenced early postoperative ileus (relative risk, 0.505; 95% confidence interval, 0.257-0.994; P=0.048). Clipless LA is comparable to conventional LA with regard to operative safety but results in significantly less pain and postoperative ileus.

Comparison of the efficacy and safety of two advanced vessel sealing technologies in total laparoscopic hysterectomy

AIM

Adequately powered, randomized controlled studies evaluating efficacy and safety of advanced bipolar energy devices in gynecologic laparoscopic surgery are very few. We aimed to compare the two most commonly used devices in total laparoscopic hysterectomy.

METHODS

This randomized controlled trial was carried out in the department of obstetrics and gynecology in an education and research hospital. One hundred thirty-two women who underwent total laparoscopic hysterectomy for benign indications were included. Women with age younger than 18 years, suspected malignancy, stage 3-4 endometriosis and cervical/intraligamentary leiomyoma were excluded. Patients were randomized preoperatively to LigaSure or Articulating Enseal. One experienced surgeon performed all operations.

RESULTS

LigaSure was used in 67 patients and Enseal was used in 65 patients. Primary outcomes of the study were operative time (time from start of sealing and transection of the round ligament until completion of colpotomy) and total operative time (time from skin incision to skin closure). Secondary outcomes were intraoperative blood loss (blood lost during operative time period) and perioperative complications. Operative time was significantly shorter in LigaSure group (P = 0.001). Total operative time, intraoperative blood loss and perioperative complications were similar. When two groups were further classified according to uterine weight taking 300 g as cut-off value, operative time was significantly shorter in LigaSure group in both subgroups (P = 0.003 and P = 0.007).

CONCLUSION

LigaSure use in total laparoscopic hysterectomy shortens operative time when compared with Enseal; without an apparent increase in intraoperative blood loss and perioperative complications. On the other side, total operative time remains unaffected.

Energy-Based Tissue Fusion for Sutureless Closure: Applications, Mechanisms, and Potential for Functional Recovery

As minimally invasive surgical techniques progress, the demand for efficient, reliable methods for vascular ligation and tissue closure becomes pronounced. The surgical advantages of energy-based vessel sealing exceed those of traditional, compression-based ligatures in procedures sensitive to duration, foreign bodies, and recovery time alike. Although the use of energy-based devices to seal or transect vasculature and connective tissue bundles is widespread, the breadth of heating strategies and energy dosimetry used across devices underscores an uncertainty as to the molecular nature of the sealing mechanism and induced tissue effect. Furthermore, energy-based techniques exhibit promise for the closure and functional repair of soft and connective tissues in the nervous, enteral, and dermal tissue domains. A constitutive theory of molecular bonding forces that arise in response to supraphysiological temperatures is required in order to optimize and progress the use of energy-based tissue fusion. While rapid tissue bonding has been suggested to arise from dehydration, dipole interactions, molecular cross-links, or the coagulation of cellular proteins, long-term functional tissue repair across fusion boundaries requires that the reaction to thermal damage be tailored to catalyze the onset of biological healing and remodeling. In this review, we compile and contrast findings from published thermal fusion research in an effort to encourage a molecular approach to characterization of the prevalent and promising energy-based tissue bond.

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.

Electrosurgery and clinical applications of electrosurgical devices in gynecologic procedures

Background: Electrosurgery is widely used in reproductive related surgeries and technological advancements to improve efficacy and reduce potential complications. However, some reports have indicated lack of sufficient knowledge and training about basic principles and technical aspects of electrosurgery among obstetricians and gynecologists.

Methods: In this paper we present a summary on basic concepts and principles of electrosurgery and review the recent evidence on the use of electrosurgical devices in gynecologic procedures including endometrial ablation, gynecologic malignancies, loop electrode excision procedure (LEEP), and infertility.

Result: Considering the extensive use of these technologies in reproductive related surgeries, procedures including laparoscopy, hysteroscopy, and loop procedures further highlights the importance of more detailed training in this field. Gynecologists must learn the basics in more detail and update their knowledge on the growing body of evidence regarding the advancements of these technologies to reduce potential complications and select the most cost-effective treatment options for each patient.

Conclusion: Try to understanding the underlying biophysical principles and more in-depth familiarity with various electrosurgical devices could lead to less complications and optimize evidence-based gynecological practice.

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.

A continuum thermomechanical model of in vivo electrosurgical heating of hydrated soft biological tissues

Radio-frequency (RF) heating of soft biological tissues during electrosurgical procedures is a fast process that involves phase change through evaporation and transport of intra- and extra-cellular water, and where variations in physical properties with temperature and water content play significant role. Accurately predicting and capturing these effects would improve the modeling of temperature change in the tissue allowing the development of improved instrument design and better understanding of tissue damage and necrosis. Previous models based on the Pennes' bioheat model neglect both evaporation and transport or consider evaporation through numerical correlations, however, do not account for changes in physical properties due to mass transport or phase change, nor capture the pressure increase due to evaporation within the tissue. While a porous media approach can capture the effects of evaporation, transport, pressure and changes in physical properties, the model assumes free diffusion of liquid and gas without a careful examination of assumptions on transport parameters in intact tissue resulting in significant under prediction of temperature. These different approaches have therefore been associated with errors in temperature prediction exceeding 20% when compared to experiments due to inaccuracies in capturing the effects of evaporation losses and transport. Here, we present a model of RF heating of hydrated soft tissue based on mixture theory where the multiphase nature of tissue is captured within a continuum thermomechanics framework, simultaneously considering the transport, deformation and phase change losses due to evaporation that occur during electrosurgical heating. The model predictions are validated against data obtained for in vivo ablation of porcine liver tissue at various power settings of the electrosurgical unit. The model is able to match the mean experimental temperature data with sharp gradients in the vicinity of the electrode during rapid low and high power ablation procedures with errors less than 7.9%. Additionally, the model is able to capture fast vaporization losses and the corresponding increase in pressure due to vapor buildup which have a significant effect on temperature prediction beyond 100 °C.

The invention of microwave surgical scissors for seamless coagulation and cutting

PURPOSE

We developed a microwave energy-based scissors device (MWCX) that is capable of performing cutting and coagulation using 2.45 GHz microwave energy. This paper aims to present the concept of the device and assess the basic functions including the hemostasis, cutting, and sealing abilities.

METHODS

Seven beagle dogs were used in our experiments. In six dogs, we measured the coagulation time (CT), lateral thermal injury (LTI), bursting pressure (BP). The dogs were then subjected to re-laparotomy 1 week later to allow us to investigate the results. In one dog, the same factors and the quantities of smoke and mist emitted were compared to those observed when using a Harmonic Focus (HF) device.

RESULTS

At 60 W, the MWCX could cut and seal small (5 s, diameter 1-2 mm) and medium-sized (10 s, 3-4 mm) vessels with complete hemostasis. The liver (length 2 cm) was cut for 30 s. Harvested vessels were sealed for 10 s (artery, 17 times; vein, six times). The mean BP was 887. 8 ± 41.5 mmHg in the medium arteries and 457.2 ± 118.0 mmHg in veins, with a mean diameter of 4.5 ± 1.3 mm. In a comparative study, the MWCX showed similar results to the HF with regard to the CT, BP and LTI, and emitted less smoke and mist.

CONCLUSION

The MWCX showed similar levels of functionality and safety to HF, as well as the advantages offered by the use of microwave energy. Microwave devices might be used in the majority of applications for which traditional energy devices are used.

A preclinical animal study of a novel, simple, and secure duct and vessel occluder for laparoscopic surgery

BACKGROUND

Secure occlusion of large blood vessels and ductal structures is critical to all surgeries and remains a challenge in many minimally invasive procedures. This study compares in vivo use of the Amsel Occluder (AO) for secure laparoscopic blood vessel and duct closure, with one of the many commercially available hemoclips (Ligaclip®), in the porcine model.

METHODS

Laparoscopic closure of vessels and ducts was performed on 12 swine to compare the ease of use, safety and efficacy of the AO with a hemoclip, as well as the tissue response at > 30 days (10 swine). All vessels and ducts were occluded and then transected between the occluding clips. Any bleeding or leakage was noted. In the chronic study, confirmation of satisfactory vessel occlusion post nephrectomy was determined by laparotomy as well as by contrast angiography and venography. The tissue response and healing was evaluated by a histopathological study for the effects of any biological incompatibilities.

RESULTS

In the acute laparoscopic study, a total of 24 occlusions between 2 and 10 mm were performed with the AO (n = 19) and hemoclip (n = 5). In the chronic study, 5 nephrectomies (AO n = 3, hemoclip N = 2) and 5 cholecystectomies (AO n = 3, hemoclip n = 2) were performed with survival ranging from 42 to 72 days. One pig who sustained a splenic injury at trocar insertion and suffered a delayed ruptured spleen with massive hemorrhage on postoperative day 22. Unlike occlusion with the AO, multiple hemoclips were used for each vessel occlusion. Histopathological examination showed no difference in the tissue response and healing of the AO and hemoclip.

CONCLUSIONS

The Amsel Vessel occluder delivered laparoscopically provides an occlusion similar to a hand-sewn transfixion suture, is simple to use, and creates an occlusion which is not only more secure, but also as safe with respect to the health of the surrounding tissues, as that of the widely used hemoclip (Ligaclip®).

Comparison of Industry-Leading Energy Devices for Use in Gynecologic Laparoscopy: Articulating ENSEAL versus LigaSure Energy Devices

STUDY OBJECTIVE

To compare 2 laparoscopic bipolar electrosurgical devices used in total laparoscopic hysterectomy (TLH). An articulating advanced bipolar device (ENSEAL G2; Ethicon Endo-Surgery, Cincinnati, OH) and an electrothermal bipolar vessel sealer (LigaSure; Medtronic, Minneapolis, MN) were analyzed for differences in surgeon perception of ease of instrument use and workload using the NASA Raw Task Load Index (RTLX) scale. A second objective was to examine differences in operative time, estimated blood loss (EBL), and perioperative complication rates between the 2 devices.

DESIGN

Single-institution, single-blinded, randomized controlled trial (Canadian Task Force classification I).

SETTING

Division of Minimally Invasive Gynecologic Surgery in a university hospital.

PATIENTS

Eligibility required planned TLH, over age 18 years, and able to give informed consent; exclusions were stage III or IV endometriosis, known gynecologic malignancy, and early decision for conversion to laparotomy. One hundred seventy-eight patients screened, 142 enrolled, 2 withdrew, and 140 completed the study. Patients were followed 1 month postoperatively.

INTERVENTIONS

Preoperative randomization to articulating advanced bipolar device or electrothermal bipolar vessel sealer to be used during TLH.

MEASUREMENTS AND MAIN RESULTS

At the end of each hysterectomy the primary surgeon completed an ergonomic assessment tool, the RTLX. Results were analyzed to detect differences in workload between the 2 devices. For each case the time to ligation of the bilateral uterine arteries, EBL, and complications (including device failure, blood transfusion, or other injury) were recorded. Statistical analysis was performed using the t test for normally distributed data, χ² test for categorical data, and Mann-Whitney U-test for nonparametric data. There were no differences in age, body mass index, parity, prior surgery, uterine weight, race, indication, pathology, and comorbidities between the 2 groups. A statistically significant increase in RTLX scores (p < .0001), device failures (p = .0031), and time to ligation of bilateral uterine arteries (p = .0281) was noted in the articulating device group. No significant differences in EBL or complication rates were noted between the groups.

CONCLUSIONS

The articulating advanced bipolar device was shown to have a statistically significant increase in surgeon-perceived workload and rate of device failure when used in TLH; however, clinical and surgical outcomes were equivalent.

"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.

Validation of a Laparoscopic Ferromagnetic Technology-based Vessel Sealing Device and Comparative Study to Ultrasonic and Bipolar Laparoscopic Devices

Introduction:

Ferromagnetic heating is a new electrosurgery energy modality that has proven effective in hemostatic tissue dissection as well as sealing and dividing blood vessels and vascularized tissue. The purpose of this study was to evaluate a ferromagnetic-based laparoscopic vessel sealing device with respect to sealing and dividing vessels and vascularized tissue and to compare performance against current vessel sealing technologies.

Materials and Methods:

A laparoscopic vessel sealing device, Laparoscopic FMsealer (LFM), was studied for efficacy in sealing and dividing blood vessels and comparative studies against predicate ultrasonic, Harmonic Ace+(US), and/or bipolar, LigaSure 5 mm Blunt Tip and/or Maryland (BP), devices in vivo using a swine model and in vitro for comparison of seal burst pressure and reliability. Mann-Whitney and Student t test were used for statistical comparisons.

Results:

In division of 10 cm swine small bowel mesentery in vivo, the laparoscopic FMsealer [12.4±1.8 sec (mean±SD)], was faster compared with US (26.8±2.5 s) and BP (30.0±2.7 s), P<0.05 LFM versus US and BP. Blinded histologic evaluation of 5 mm vessel seals in vivo showed seal lateral thermal spread to be superior in LFM (1678±433 μm) and BP (1796±337 μm) versus US (2032±387 μm), P<0.001. In vitro, seal burst strength and success of sealing 2 to 4 mm arteries were as follows (mean±SD mm Hg, % success burst strength >240 mm Hg): LFM (1079±494 mm Hg, 98.1% success) versus BP (1012±463, 99.0%), P=NS. For 5 to 7 mm arteries: LFM (1098±502 mm Hg, 95.3% success) versus BP (715±440, 91.8%), P<0.001 in burst strength and P=NS in % success. Five 60 kg female swine underwent 21-day survival studies following ligation of vessels ranging from 1 to 7 mm in diameter (n=186 total vessels). Primary seal was successful in 97%, 99% including salvage seals. There was no evidence of postoperative bleeding at sealed vessels at 21-day necropsy.

Conclusion:

The Laparoscopic FMsealer is an effective tool for sealing and dividing blood vessels and vascularized tissue and compares favorably to current technologies in clinically relevant end points.

Is the bipolar vessel sealer device an effective tool in robotic surgery? A retrospective analysis of our experience and a meta-analysis of the literature about different robotic procedures by investigating operative data and post-operative course

BACKGROUND

The latest robotic bipolar vessel sealing tools have been described to be effective allowing to perform procedures with reduced blood loss and shorter operative times. The aim of this study was to assess the efficacy and reliability of these devices applied in different robotic procedures.

MATERIAL AND METHODS

All robotic operations, between 2014 and 2016, were performed using the EndoWrist One VesselSealer (EWO, Intuitive Surgical, Sunnyvale, CA), a bipolar fully wristed device. Data, including age, gender, body mass index (BMI), were collected. Robot docking time, intraoperative blood loss, robot malfunctioning and overall operative time were analyzed. A meta-analysis of the literature was carried out to point the attention to three different parameters (mean blood loss, operating time and hospital stay) trying to identify how different coagulation devices may affect them.

RESULTS

In 73 robotic procedures, the mean operative time was 118.2 minutes (75-125 minutes). Mean hospital stay was four days (2-10 days). There were two post-operative complications (2.74%).

CONCLUSIONS

The bipolar vessel sealer offers the efficacy of bipolar diathermy and the advantages of a fully wristed instrument. It does not require any change of instruments for coagulation or involvement of the bedside assistant surgeon. These characteristics lead to a reduction in operative time.

Prevention, Recognition, and Management of Urologic Injuries During Gynecologic Surgery

The urethra, bladder, and ureters are particularly susceptible to injury during gynecologic surgery. When preventive measures fail, prompt recognition and management of injury can avoid long-term sequelae such as fistula formation and loss of renal function. Intraoperative identification should be the primary goal when an injury occurs, although this is not always possible. Postoperative injury recognition requires a high level of suspicion and vigilance. In addition to history and physical examination, appropriate radiologic studies can be useful in localizing injury and planning management strategies. Some injuries may require Foley catheter drainage or ureteral stenting alone, whereas others will require operative intervention with ureteral resection and reanastomosis or reimplantation. Prompt restoration of urinary drainage or diversion will avoid further renal compromise.

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 ±

Prospective analysis of the sealing ability of the ENSEAL® G2 Articulating Tissue Sealer and transector on human mesenteric vessels in colorectal surgery

BACKGROUND

The sealing and transection of mesenteric vessels is a crucial step in minimally invasive colorectal surgery. We examined the sealing quality of the ENSEAL^® G2 Articulating Tissue Sealer in three different articulations in mesenteric vessels.

METHODS

This was a prospective experimental study within a tertiary healthcare center, and 30 patients were recruited. Burst pressures for each specimen were measured as the primary outcome. Ten specimens at each of the three articulations were also histologically assessed for the quality of seal.

RESULTS

We evaluated 54 sets of specimens from 30 patients for bursting pressure, all of which were harvested and sealed in the operating room. No statistical difference was seen in burst pressures from seals recorded at no angulation, half-maximal angulation, or maximal angulation (1604, 1507, 1478 mmHg; p = 0.07). Histological analysis showed no statistical differences in the average vessel diameter (p = 0.57), lateral extent of thermal injury (p = 0.48), degree of vascular sclerosis, or the integrity of seal at the three articulations. No cases of intraoperative or postoperative bleeding were observed in any of the patients. Five (16.7%) of the ENSEAL^® devices developed breaks in the black, heat-shrink, polyethylene covering as a result of repeated articulation and disarticulation. Electrical arcing did not appear to have occurred as a result of the break, although this was not formally examined.

CONCLUSIONS

The maximum sustainable pressure in mesenteric vessels sealed with a bipolar electrothermal device is supraphysiological, and consequently, the device can be safely used at various articulations to seal vessels during colorectal surgery.

Lateral thermal damage of mesoappendix and appendiceal base during laparoscopic appendectomy in children: comparison of the harmonic scalpel (Ultracision), bipolar coagulation (LigaSure), and thermal fusion technology (MiSeal)

BACKGROUND

The aim of this study was to compare lateral thermal damage of mesoappendix and appendiceal base using three different instruments for sealing and cutting of mesoappendix.

MATERIALS AND METHODS

A total number of 99 patients (54 males and 45 females) who underwent laparoscopic appendectomy because of suspected appendicitis between December 2013 and May 2015 were enrolled in the study. The patients were divided in three groups based on instrument used for sealing of mesoappendix: group 1 (Ultracision; n = 36), group 2 (LigaSure; n = 32), and group 3 (MiSeal; n = 31). Lateral thermal damage, intraoperative and postoperative complications, duration of surgery, hospital stay, and economic value were compared within groups.

RESULTS

The median age of patients was 14 y (range 3-17). A histopathologic analysis revealed a positive diagnosis of appendicitis in 84 patients (85%). The median lateral thermal damage on appendiceal base using Ultracision, LigaSure, and MiSeal was 0.10 mm, 0.16 mm, and 0.10 mm respectively, and on mesoappendix, 0.08 mm, 0.13 mm, and 0.08 mm, respectively. Significantly higher thermal damage was found on mesoappendix (P = 0.015) and appendiceal base (P = 0.012) in patients treated with LigaSure than in patients from other groups. There were no statistical differences among the groups regarding intraoperative and postoperative complications (P = 0.098). No significant difference in thermal damage between appendicitis and nonappendicitis group was found (P = 0.266).

CONCLUSIONS

Using of Ultracision, LigaSure, and MiSeal for sealing of mesoappendix in laparoscopic appendectomy in children is safe and useful. LigaSure produces significantly greater lateral thermal damage compared with other instruments.

Strength and Persistence of Energy-Based Vessel Seals Rely on Tissue Water and Glycosaminoglycan Content

Vessel ligation using energy-based surgical devices is steadily replacing conventional closure methods during minimally invasive and open procedures. In exploring the molecular nature of thermally-induced tissue bonds, novel applications for surgical resection and repair may be revealed. This work presents an analysis of the influence of unbound water and hydrophilic glycosaminoglycans on the formation and resilience of vascular seals via: (a) changes in pre-fusion tissue hydration, (b) the enzymatic digestion of glycosaminoglycans (GAGs) prior to fusion and (c) the rehydration of vascular seals following fusion. An 11% increase in pre-fusion unbound water led to an 84% rise in vascular seal strength. The digestion of GAGs prior to fusion led to increases of up to 82% in seal strength, while the rehydration of native and GAG-digested vascular seals decreased strengths by 41 and 44%, respectively. The effects of increased unbound water content prior to fusion combined with the effects of seal rehydration after fusion suggest that the heat-induced displacement of tissue water is a major contributor to tissue adhesion during energy-based vessel sealing. The effects of pre-fusion GAG-digestion on seal integrity indicate that GAGs are inhibitory to the bond formation process during thermal ligation. GAG digestion may allow for increased water transport and protein interaction during the fusion process, leading to the formation of stronger bonds. These findings provide insight into the physiochemical nature of the fusion bond, its potential for optimization in vascular closure and its application to novel strategies for vascular resection and repair.

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.

A novel secure transfixing blood vessel occluder: comparison with the hemoclip in the porcine model

BACKGROUND

Secure vessel occlusion is critical to the success of all surgical and interventional procedures. The purpose of this study was to compare in vivo the use of the Amsel Vessel Occluder (AVO), a novel occlusion clip device for secure blood vessel closure, with one of the many commercially available hemoclips, the Ligaclip, in the porcine model.

METHODS

Vessel closure of arteries and veins was performed on 10 swine to compare the ease of use, safety, and efficacy of the AVO with the Ligaclip as well as the tissue response at 7 and 30 d. After heparinization, the targeted vessels (carotid/femoral/brachial arteries and jugular/femoral/brachial veins) were occluded with two clips, either two AVO's or two Ligaclip's, and the vessels transected between the two clips. Any bleeding was recorded. At sacrifice, gross and histopathologic findings were examined for evidence of bleeding or injury to adjacent structures. The tissue response and healing were evaluated by a prospective randomized histopathologic study for the effects of any biological incompatibilities. At time of sacrifice, occluded vessel segments were subjected to nonphysiological pressures ("holding" pressures) to compare efficacy of occlusion in fresh, nonoccluded vessels, and the ability to dislodge the clips once applied.

RESULTS

Twenty veins and 20 arteries between 2-mm and 7-mm outer diameter were occluded in 10 pigs. Each vessel was occluded with either AVO or Ligaclip. Our study confirmed easy and safe AVO application with no dislodgment of any AVO clips once deployed. The AVO showed no intraoperative or postoperative bleeding (AVO = 0/40), while one Ligaclip dislodged resulting in a fatal hemorrhage 16 h after surgery (Ligaclip = 1/40), and on two occasions where, with obvious slippage of the Ligaclip, immediately after deployment, additional clips were placed. The holding pressures for the two clips were similar but unlike the AVO, the Ligaclip was easily dislodged. Histopathologic examination showed no difference in the tissue response and healing of the two clips.

CONCLUSIONS

The AVO is simple to deploy and securely maintains occlusion by transfixing the targeted vessel, unlike the widely used, nontransfixing Ligaclip, that has a tendency to dislodge. As such, the Amsel secure vessel occluder opens up numerous treatment opportunities in both the venous and arterial systems to minimize open, laparoscopic, robotic surgical and interventional procedures, and reduce patient morbidity and its associated health care costs.

Comparative analysis between a bipolar vessel sealing and cutting device and the tie and suture technique in thyroidectomy: A randomized clinical trial

BACKGROUND

Advanced bipolar and ultrasonic devices have shown significant reduction in the surgical time of thyroid operations. This randomized, controlled trial assessed if operative time and other relevant outcomes are different for thyroidectomies performed either with a second-generation advanced bipolar device or traditional tie and suture technique.

METHODS

Forty-one patients were randomized into 2 groups (advanced bipolar device and traditional tie and suture). Secondary end points included estimated blood loss, postoperative hemorrhage or hematoma requiring operative reintervention, recurrent laryngeal nerve injury, hypoparathyroidism, pain intensity, number of ligatures, analgesia usage, and loss of signal during recurrent laryngeal nerve monitoring.

RESULTS

Preoperative characteristics were similar between both groups. Mean operative time in the advanced bipolar device group was reduced by 32.5 minutes compared with the traditional tie and suture group (P = .006). Intraoperative blood loss was similar in both groups. Four patients presented postoperative vocal cord dysmotility, 3 in the traditional tie and suture group and 1 in the advanced bipolar device group (P = ns). Two of these 4 patients also had a >50% amplitude decrease during continuous intraoperative neuromonitoring, 1 in each group. Pain intensity, 12 hours after operation, was significantly greater in the traditional tie and suture group (P = .015), even though pain medication requirements during the initial 24 hours after operation were similar between groups (P = .97). There were no cases of postoperative hemorrhage or hematoma requiring reintervention. Postoperative, symptomatic hypocalcemia occurred in 6 patients, 4 in the traditional tie and suture, and 2 in the advanced bipolar device group. One of them developed permanent hypocalcemia.

CONCLUSION

The use of an advanced bipolar device in thyroid operation reduces operative time by >30 minutes, with a similar postoperative outcome profile when compared with the traditional tie and suture technique.

Large-Vessel Sealing in Laparoscopic Colectomy with an Ultrasonic Device

BACKGROUND AND OBJECTIVE

The Harmonic ACE+7 Shears with Advanced Hemostasis Mode (Ethicon, Somerville, NJ, USA) is an ultrasonic device designed to transect and seal vessels up to 7 mm in diameter. The device applies an algorithm that optimizes ultrasonic energy delivery combined with a longer sealing cycle. The purpose of this study was to assess the initial clinical experience with the Harmonic device by evaluating large-vessel sealing during laparoscopic colectomy in consecutive cases.

METHODS

This prospective, multicenter, observational series involved 40 adult patients who were to undergo elective laparoscopic colectomy where dissection and transection of the inferior mesenteric artery was indicated. The primary study endpoint was first-pass hemostasis, defined as a single activation of the Advanced Hemostasis Mode to transect and seal the inferior mesenteric artery. The use of any additional energy device or hemostatic product to establish or maintain hemostasis was noted. Patients were observed after surgery for ∼4 weeks for adverse events that were considered to be related to the study procedure or study device. Descriptive statistical analyses were performed for study endpoints.

RESULTS

Forty patients underwent the laparoscopic colectomy procedure. First-pass hemostasis of the inferior mesenteric artery was achieved and maintained in all 40 patients, with no required additional hemostatic measures. Exposure of the vessel was reported as skeletonized in 22 of 40 (55%) patients. Mean transection time was 21.9 ± 7.4 s. One adverse event (postoperative anemia) was considered possibly related to the study device.

CONCLUSION

In this initial clinical consecutive series, the device demonstrated successful transection and sealing of the large mesenteric vessels during laparoscopic colorectal surgery.

Clinical utility of a novel ultrasonic vessel sealing device in transecting and sealing large vessels during laparoscopic hysterectomy using advanced hemostasis mode

OBJECTIVE(S)

The ultrasonic advanced energy study device (AH device) is the first surgical device indicated to seal vessels up to and including 7mm using ultrasonic technology alone. This study assesses clinical experience during total laparoscopic hysterectomy (TLH) using advanced hemostasis mode (AHM).

STUDY DESIGN

This was a prospective, non-randomized, single arm, multicenter, observational study which did not modify or influence current surgeon technique for elective TLH for benign disease. Each surgeon assessed hemostasis, defined as the hemostatic transection of the uterine vasculature (left/right) with at least one use of the AH device in AHM without the use of additional hemostatic measures other than the AH device. Patients were followed for 4-6 weeks after surgery. Vessel sealing performance was quantitatively assessed for transection and sealing of the uterine artery (UA), the uterine pedicle (UP; defined as cases where the UA could not be 'isolated') and the ovarian pedicle (OP) (when indicated). Adverse events (AEs) related to the AH device or procedures were collected.

RESULTS

Forty patients underwent the procedure. Mean age was 49 years and mean body mass index was 28kg/m(2). Mean surgical duration was 88min. None required conversion to open procedure. Using only the AH device, hemostasis was achieved and maintained in 119 (94.4%) transections (both left and right sides of the UA/UP and OP). Additional hemostasis was achieved in 5 patients using conventional bipolar (4) or monopolar (1) energy. No patient required a blood transfusion postoperatively. Only one adverse event of pain was considered to be related to the use of the ultrasonic AH device during this study.

CONCLUSION

These results support that the AH device with its AHM has clinical utility in sealing named vessels in TLH. The new algorithm to deliver energy in the AHM has the potential to reduce the need for additional hemostatic devices or products as well as the potential to reduce the need for multiple instrument changes during surgery.

Sealing of vessels larger than 7 millimeters using Enseal in porcine aorta

Background:

The Enseal (Ethicon Endo-Surgery, Blue Ash, Ohio) tissue-sealing device has proven efficacy for ligation of vessels <7 mm in diameter, even with significant supraphysiologic bursting pressures. We aimed to evaluate the safety of Enseal in porcine vessels >7 mm.

Materials and Methods:

The lumbar aortas of pigs that were euthanized for unrelated procedures were harvested. A 5- to 6-cm segment of aorta was sealed using the Enseal device. The opposite end was attached to a pressure-testing device to measure pressures at leak or bursting. The bivariate Pearson correlation was used to determine the relationship between diameter and bursting pressure. One-way analysis of variance was used to determine differences between the groups of vessels on the basis of their diameter.

Results:

Ninety samples of 5-cm aorta segments were used to assess bursting pressure. The median diameter was 14 mm (range, 7–18) and bursting pressure was 85 mm Hg (range, 24–650). The Pearson test showed a negative correlation between vessel diameter and bursting pressure (P = .25). One-way analysis of variance did not show any significant difference between vessel diameters grouped by size (P = .517), and neither did the Scheffe post hoc test when comparing diameter with bursting pressure; 31% of specimens failed to seal.

Conclusions:

Bursting pressures are low and inconsistent after tissue sealing with the Enseal device in porcine vessels >7 mm. These vessels also demonstrated a higher rate of failure to seal. The histologic results of the aorta segments (ie, a low collagen-elastin ratio) may be the cause of the low bursting pressures.

Bond Strength of Thermally Fused Vascular Tissue Varies With Apposition Force

Surgical tissue fusion devices ligate blood vessels using thermal energy and coaptation pressure, while the molecular mechanisms underlying tissue fusion remain unclear. This study characterizes the influence of apposition force during fusion on bond strength, tissue temperature, and seal morphology. Porcine splenic arteries were thermally fused at varying apposition forces (10-500 N). Maximum bond strengths were attained at 40 N of apposition force. Bonds formed between 10 and 50 N contained laminated medial layers; those formed above 50 N contained only adventitia. These findings suggest that commercial fusion devices operate at greater than optimal apposition forces, and that constituents of the tunica media may alter the adhesive mechanics of the fusion mechanism.