Sealing of pulmonary arteries with LigaSure: In vivo and ex vivo examinations

"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.

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.

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.

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.

Experimental study in pulmonary artery sealing with a vessel-sealing device

Background

The development of vessel-sealing devices will facilitate safety in video-assisted thoracoscopic surgery. Our objective was to evaluate the feasibility and safety of sealing pulmonary arteries with the Enseal tissue-sealing device.

Methods

Pulmonary arteries from beagle dogs (mean body weight 13.1 kg, range 10.5–15.4 kg) were divided into 3 groups according to the in-vivo sealing method used (Enseal, ligation, and proximal ligation plus distal Enseal) and extracted to evaluate the pressure tolerance up to 75 mm Hg at the sealed end. A left lower lobectomy was performed to evaluate chronic-phase durability of the sealed stumps in a survival model. Two or three branches of the pulmonary arteries in each dog were allocated to each of the 3 groups. After the scheduled survival period, the pulmonary arteries were sampled.

Results

Pressure tolerance at the sealed end was evaluated in 91 pulmonary artery sections. All sealed ends showed pressure tolerance >75 mm Hg. A left lower lobectomy was performed in 13 dogs in which 35 pulmonary artery sections had been allocated into the 3 groups. No sealing failure was found, and pathological findings showed healing and persistent hemostasis at all sealed ends of the pulmonary arteries after 2 and 4 weeks of the survival period.

Conclusions

Pulmonary arteries sealed in vivo with the Enseal device showed pressure tolerance >75 mm Hg in the acute phase, and persistent hemostasis after 2 or 4 weeks. Pulmonary artery sealing with the Enseal device is feasible and safe in thoracic surgery settings.

More compression improves sealing effect on larger pulmonary arteries

BACKGROUND

Small arteries and veins up to 7 mm can be sealed safe and divided with a bipolar sealing instrument. The results for the safe sealing of larger vessels were unsatisfactory in the past. Using an ex vivo pulmonary artery model, we aimed to investigate, if a higher compression force and duration will improve the bursting pressures in case of vessels >7 mm.

MATERIAL AND METHODS

Heart-lung preparations (from 90 kg pigs) were removed en bloc at a slaughterhouse. The whole pulmonary artery was exposed from the pulmonary valve up to the periphery of the left lung. In the laboratory, a digital pressure sensor was implanted in the central end of the blood vessel to measure the bursting pressure (in mbar). The vessels examined were divided into three groups by diameter: 1-6 mm, 7-12 mm and >12 mm. After bipolar sealing, bursting pressures were determined by pneumatic testing. Seals were made using three equal MARSEAL instruments (Gebrüder Martin GmbH & CoKG, Tuttlingen, Germany) with a SealSafe G3 electric current and different jaw compression forces of each 35 N, 45 N, and 55 N. Bursting pressures were also measured for different compression durations (0 s, 5 s, 10 s, and 20 s) with 35 N compression. Mean bursting pressures were calculated for each group (n = 15). Groups were compared using a nonparametric test (Mann-Whitney U test). The significance level was P < 0.05.

RESULTS

Mean bursting pressures in the 1-6 mm blood vessels were 290.5 ± 77.1 mbar (35 N), 323.0 ± 76.0 mbar (45 N) and 301.6 ± 69.9 mbar (55 N). The groups did not differ significantly. Mean bursting pressures in the 7-12 mm vessels were 108.1 ± 19.1 mbar (35 N), 154.3 ± 28.5 mbar (45 N), and 212.4 ± 45.3 mbar (55 N). In blood vessels >12 mm in diameter, we found mean bursting pressures of 77.7 ± 11.7 mbar (35 N), 117.6 ± 27.1 mbar (45 N), and 166.3 ± 56.6 mbar (55 N). The results for the groups with 55 N compression were significantly higher than for the other groups. A compression duration of 5 s led to significantly higher mean bursting pressures than a duration of 0 s but a duration of >5 s did not bring a further significant increase in mean bursting pressure. Histologic staining of the seal zone and microscopic examination did not reveal any differences relating to compression force.

CONCLUSIONS

With a higher compression force, we reached satisfactory bursting pressures in case of pulmonary arteries >7 mm. An additional 5 s of compression before starting coagulation brings a further significant increase in bursting pressure. However, there is no advantage in a longer compression.

Electrocautery device does not provide adequate pulmonary vessel sealing in transumbilical anatomic pulmonary lobectomy

INTRODUCTION

Safe pulmonary vessel sealing device plays a crucial role in anatomic lung resection. In 2014, we reported high rates of massive bleeding complications during transumbilical lobectomy in a canine model due to difficulty in managing the pulmonary vessel with an endostapler. In this animal survival series, we aimed to evaluate the outcome of pulmonary vessel sealing with an electrocautery device to simplify the transumbilical thoracic surgery.

METHODS

Under general anesthesia, a 3-cm longitudinal incision was made over the umbilicus. Under video guidance, a bronchoscope was inserted through the incision for exploration. The diaphragmatic wound was created with an electrocautery knife and used as the entrance into the thoracic cavity. Using the transumbilical technique, anatomic lobectomy was performed with electrosurgical devices and endoscopic vascular staplers in 15 canines.

RESULTS

Transumbilical endoscopic anatomic lobectomy was successfully completed in 12 of the 15 animals. Intraoperative bleeding developed in three animals during pulmonary hilum dissection, where one animal was killed due to hemodynamic instability and the other two animals required thoracotomy to complete the operation. There were five delayed bleeding and surgical mortality cases caused by inadequate vessel sealing by electrosurgical devices. Postmortem examination confirmed correct transumbilical lobectomy in the twelve animals that survived the operations.

CONCLUSION

Transumbilical anatomic lobectomy is technically feasible in a canine model; however, the electrosurgical devices were not effective in sealing the pulmonary vessel in the current canine model.

A pilot prospective randomized, controlled trial comparing LigaSure™ tissue fusion technology with the ForceTriad™ energy platform to the electrosurgical pencil on rates of atrial fibrillation after pulmonary lobectomy and mediastinal lymphadenectomy

OBJECTIVES

The use of bipolar sealing devices during pulmonary resection is particularly useful in thoracoscopic surgery. Theoretically, a bipolar device, which contains the current in a smaller area and completes the current cycle only through the tissue between the electrodes, may reduce the proportion of patients experiencing atrial fibrillation compared with monopolar devices such as the electrosurgical pencil using which the current completes the cycle through the patient. We investigated the impact of the LigaSure™ (LS) tissue fusion technology with the ForceTriad™ energy platform device on the incidence of postoperative atrial fibrillation and on the reduction of postoperative chest tube output and hospital length of stay after open pulmonary lobectomy.

METHODS

A pilot prospective randomized, controlled trial comparing LS tissue fusion technology with the ForceTriad™ energy platform to the conventional electrosurgical pencil. Overall, 146 patients with resectable lung cancer were recruited at the Division of Thoracic Surgery of the Istituto Nazionale Tumori, Fondazione Pascale, IRCCS, between January 2011 and July 2013. Of these, 119 candidates to open lobectomy for non-small-cell lung cancer were randomized to either LS tissue fusion technology with the ForceTriad™ energy platform (LS: 57 patients) or standard haemostatic procedure (standard treatment, ST: 62 patients) for hilar and mediastinal nodal dissection. The primary end-point was to compare the incidence of postoperative atrial fibrillation of LS compared with ST. The secondary end-point was to compare the efficacy of LS compared with ST in terms of total chest tube drainage, daily chest tube drainage and chest tube duration.

RESULTS

There was no statistically significant difference between LS and ST in terms of postoperative atrial fibrillation (P=0.31). However, LS was associated to significant reduction of duration of both mediastinal nodal dissection (P=0.017) and the cumulative chest tube drainage (P=0.025).

CONCLUSIONS

The incidence of atrial fibrillation with LS tissue fusion technology with the ForceTriad™ energy platform is not reduced as compared with conventional electrosurgical pencil. However, the use of LS during mediastinal nodal dissection is associated to shorter duration of lymphadenectomy and duration of chest tube drainage.

Usefulness of vessel-sealing devices for ≤7 mm diameter vessels: a randomized controlled trial for human thoracoscopic lobectomy in primary lung cancer

OBJECTIVES

Vessel-sealing devices (VSDs) are widely used for various surgical procedures, including thoracoscopic surgery, but very few reports have compared their safety and usefulness with human thoracoscopic lobectomy procedures not employing VSDs.

METHODS

Primary lung cancer patients for whom a thoracoscopic lobectomy involving mediastinal lymph node dissection was planned in our department from April 2011 to March 2013 were recruited for the study. Patients were randomly allocated to a control group (n = 14) or a VSD group (n = 44), which comprised three sub-groups, namely EnSeal (n = 17), LigaSure (n = 15) and Harmonic (n = 12). The control group comprised patients undergoing surgery solely with ligation and conventional electrocautery. EnSeal, LigaSure and Harmonic were chosen because they are the three most popular disposable VSDs used in Japan. In the VSD groups, the proximal side of pulmonary artery stumps (≤7 mm diameter) were ligated and then treated with respective devices. Primary end-points were burst pressure of the pulmonary artery stump (measured using resected specimens), operative time, intraoperative blood loss, instances of endostapler use, intraoperative surgeon stress (assessed by visual analogue scale) and postoperative drainage volume and duration. As a secondary objective, the individual VSD groups were also compared with each other.

RESULTS

The burst pressure of ligation-treated pulmonary artery stumps was higher than that of VSD-treated stumps (P <0.0001). The burst pressure of <5-mm-wide VSD-treated stumps was higher than that of ≥5-mm-wide stumps (P = 0.0421). However, the burst pressure for all groups and all vessel diameters was sufficient to withstand the physiological pulmonary artery pressure. The VSD group demonstrated reduced intraoperative blood loss (P = 0.0241), surgeon stress (P = 0.0002), postoperative drainage volume (P = 0.0358) and shortened postoperative drainage duration (P = 0.0449). Operative time and the instances of endostapler use did not significantly differ. Comparison between each of the VSD groups revealed no significant differences. None of the patients experienced serious perioperative complications or died because of surgery.

CONCLUSION

VSD is simple and safe to use in thoracoscopic lobectomy involving mediastinal lymph node dissection for primary lung cancer. Furthermore, none of the VSDs used in this study presented any observable differences in quality that could lead to clinical problems.