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.

Very-Low Energy Monopolar Reduces Post-Tonsillectomy Hemorrhage Versus Standard Energy Techniques

OBJECTIVES/HYPOTHESIS

To compare rates of post-tonsillectomy hemorrhage (PTH) between a very-low energy transfer monopolar technique (VLET) and standard energy techniques.

STUDY DESIGN

Retrospective controlled cohort study.

METHODS

All tonsillectomies performed by practice physicians during the period January 1, 2010 to August 31, 2019 were identified. Three groups were created based on surgeon technique utilization: the study group (VLET) and two control groups (exclusive standard energy monopolar [Standard]; exclusive "hot" technique without exclusive monopolar use [Mixed "Hot"]). Each group's PTH occurrences requiring surgical intervention (PTHRSI) were identified and rates compared.

RESULTS

During the study period 11,348 tonsillectomies were performed (4,427 Standard, 1,374 VLET, 5,547 Mixed "Hot"), and 167 (1.47%) PTHRSI events identified (14 primary (<24 hours), 153 secondary (>24 hours), 12 repeat (>1PTHRSI/patient). Compared to the Standard group secondary and total PTHRSI rates (1.47%, 1.60%), the Mixed "Hot" group experienced similar rates (1.57%, P = .54; 1.68%, P = .64), but the VLET group experienced significantly lower rates (0.15%, P = .0026, adjusted odds ratio [OR] 0.114 [0.028-0.469]; 0.22%, P = .0016, adjusted OR 0.155 [0.048-0.494]). Age was a significant risk factor for both secondary and total PTHRSI (P = .0025, P = .0024, adjusted OR 1.02/year [1.01-1.03]). No significant difference in rate of primary PTHRSI was seen collectively or in any age group. The <12VLET Group experienced 0 episodes of secondary PTHRSI and a total PTHRSI rate of 0.09% in 1060 tonsillectomies.

CONCLUSIONS

Standard energy techniques had an adjusted odds ratio over 8-fold higher for secondary PTHRSI and over 6-fold higher for total PTHRSI compared to the minimized energy transfer VLET technique.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Steam induced by the activation of energy devices under a wet condition may cause thermal injury

BACKGROUND

During esophagectomy for esophageal cancer, meticulous attention is needed to prevent thermal injury to the vital organs, such as the recurrent laryngeal nerve (RLN) and tracheobronchus. In order to clarify the novel mechanism behind thermal injury induced by energy devices, we investigated the temperature of steam with the use of two different devices under wet and dry conditions.

METHODS

An ultrasonic device (Sonicision™) and a vessel sealing device (Ligasure™) were studied. We evaluated the temperature at the tip of the devices and the steam when the devices were activated under different grasping ranges, under four different combinations of device and muscle, and under four different wet/dry conditions (dry-dry, dry-wet, wet-dry, and wet-wet).

RESULTS

Although the maximum temperature of the devices was significantly higher with Sonicision™ than with Ligasure™, the maximum temperature of the steam was significantly higher with Ligasure™ than with Sonicision™ in almost all situations. At 1 mm away from Sonicision™, the critical temperature more than 60 °C was observed only when used with one-third grasping range under the wet-dry or the wet-wet conditions. In case of Ligasure™, high-temperature steam was observed when used with one-third grasping under the wet-dry or the wet-wet condition and two-third grasping under the dry-wet, the wet-dry, or the wet-wet condition. Under the wet condition, the emission of steam from the non-grasping part of Ligasure™ caused a spike in temperature that exceeded the critical temperature.

CONCLUSION

We demonstrated that the use of energy devices under a wet condition generates steam from the non-grasping part of the devices. The temperatures of steam from Ligasure™ were significantly higher than that from Sonicision™. To prevent thermal injury to the vital organs, a very attentive and meticulous surgical technique is imperative considering the characteristics of each device.

Spontaneous rupture of the uterus following salpingectomy: a case report and literature review

Laparoscopic salpingectomy (LPSC) is the main treatment for ectopic pregnancy, which leads to spontaneous uterine rupture (UR) during pregnancy. We report the characteristics of a woman who had spontaneous UR during pregnancy with a history of salpingectomy. We experienced a 31-year-old woman with a UR in pregnancy with a history of LPSC twice. The patient had a successful pregnancy. We also performed a literature review including cases with spontaneous UR after LPSC. Twenty-seven case reports of 48 women were included in our review. Thirty-five (83.33%, 35/42) women previously received LPSC and 15 (31.25%) developed interstitial pregnancies. The interval between pregnancy and the last surgery did not affect the frequency of interstitial pregnancy and gestational age. Fetal outcomes in patients with UR at the third trimester were better than those at the first and second trimesters. We suggest that close observation and timely treatment by experienced clinicians lead to good outcomes of pregnant women with suspected UR.

Prevention of Nerve Root Thermal Injury Caused by Bipolar Cauterization Near the Nerve Roots

STUDY DESIGN

This was a controlled, interventional animal study.

OBJECTIVE

This study aimed to investigate the thermal injury of nerve root by cauterization near the nerve root and to identify the prevention or rescue procedure of nerve root injury.

SUMMARY OF BACKGROUND DATA

In spine surgery, bipolar cauterization of epidural venous plexus near the nerve root is an essential procedure to control bleeding. Although a potential risk of neurological thermal damage exists, the underlying mechanism and prevention have not been elucidated.

METHODS

Temperature measurement and histological evaluation after bipolar cauterization near the posterior branch of the nerve root were performed using a rabbit model. Subsequently, the effect of saline irrigation or changing the direction of bipolar forceps to reduce thermal elevation during bipolar cauterization was evaluated. Finally, the effectiveness of locally injected corticosteroid after bipolar cauterization was evaluated.

RESULTS

After bipolar cauterization, temperature of the surrounding site reached 60.9 °C, and 47.8% of the nerves were histologically injured. Using saline irrigation, thermal elevation was significantly suppressed up to 42.7 °C (P < 0.01), and no nerve was histologically injured. When bipolar cauterization was performed in the perpendicular direction, temperature of the surrounding site reached only 40.4 °C (P < 0.01). Locally injected corticosteroid reduced the incidence of nerve injury to 25.0%. However, a significant increase in nerve damage remained compared with the sham group (P < 0.01).

CONCLUSION

Bipolar cauterization near the nerve roots can increase the temperature of nerve roots and cause thermal nerve root injury, despite no accidental direct nerve root injury. Using saline irrigation, or setting bipolar forceps perpendicular to nerve roots, thermal elevation could be suppressed and nerve injury could be prevented. Therefore, it is recommended that surgeons set bipolar forceps perpendicular to nerve roots or use saline irrigation for the prevention of nerve root injury.

LEVEL OF EVIDENCE

N/A.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of Anti-Sticking Nanostructured Surface Coating on Minimally Invasive Electrosurgical Device in Brain

The purpose of the present study was to examine the extent of thermal injury in the brain after the use of a minimally invasive electrosurgical device with a nanostructured copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize an electrosurgical device in clinical surgery, it is important to decrease the thermal injury to the adjacent tissues. The surface characteristics and morphology of DLC-Cu thin film was evaluated using a contact angle goniometer, scanning electron microscopy, and atomic force microscopy. Three-dimensional biomedical brain models were reconstructed using magnetic resonance images to simulate the electrosurgical procedure. Results indicated that the temperature was reduced significantly when a minimally invasive electrosurgical device with a DLC-Cu thin film coating (DLC-Cu-SS) was used. Temperatures decreased with the use of devices with increasing film thickness. Thermographic data revealed that surgical temperatures in an animal model were significantly lower with the DLC-Cu-SS electrosurgical device compared to an untreated device. Furthermore, the DLC-Cu-SS device created a relatively small region of injury and lateral thermal range. As described above, the biomedical nanostructured film reduced excessive thermal injury with the use of a minimally invasive electrosurgical device in the brain.

Biomedical electrosurgery devices containing nanostructure for minimally invasive surgery: reduction of thermal injury and acceleration of wound healing for liver cancer

The aim of the present study was to investigate the thermal injury in the liver after a minimally invasive electrosurgery technique with a copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize electrosurgery in a clinical caner setting, it is necessary to suppress the thermal injury to adjacent tissues. The surface morphologies of DLC-Cu thin films were characterized using scanning electron microscopy and transmission electron microscopy. Three-dimensional liver models were reconstructed using magnetic resonance imaging to simulate the electrosurgical procedure. Our results indicated that the temperature decreased significantly when minimally electrosurgery with nanostructured DLC-Cu thin films was used, and that it continued to decrease with increasing film thickness. In an animal model, thermography revealed that the surgical temperature was significantly lower in the minimally invasive electrosurgery with DLC-Cu thin film (DLC-Cu-SS) compared to untreated electrosurgery. In addition, DLC-Cu-SS created a relatively small thermal injury area and lateral thermal effect. These results indicated that the biomedical nanostructure coating reduced excessive thermal injury, and uniformly distributed temperature in the liver.

Optical magnification devices in tonsillectomy: a prospective randomised clinical study

Tonsillectomy is one of the most common surgical procedure in otorhinolaryngology. A plethora of approaches has been undertaken so far to limit postoperative pain, one of the major problems patients are concerned with. Thermal damages of the surrounding tissue caused by coagulation during surgery are discussed to correlate with postoperative pain. Therefore, we studied whether the use of magnification devices reduced coagulation procedures and consequently limited post-operative pain. Following an intraindividual design, we performed tonsillectomy on one side using a microscope or magnifying glasses whereas the opposite side was operated with unsupported vision. As verified by a visual analogue scale, our study shows that neither the use of a microscope, nor the use of magnifying glasses leads to less post-operative pain. Other parameters like post-operative bleeding, duration of surgery, and total applied energy by bipolar coagulation were also comparable in the different treatment groups. Taken together, magnification-supported tonsillectomy does not seem to be appropriate for limiting complications of tonsillectomy, especially not for reducing post-operative pain.

Sealing vessels up to 7 mm in diameter solely with ultrasonic technology

Introduction

Ultrasonic energy is a mainstay in the armamentarium of surgeons, providing multifunctionality, precision, and control when dissecting and sealing vessels up to 5 mm in diameter. Historically, the inability to seal vessels in the 5–7 mm range has been perceived as an inherent limitation of ultrasonic technology. The purpose of this study was to evaluate sealing of vessels up to 7 mm in diameter with an ultrasonic device that modulates energy delivery during the sealing period.

Methods

In ex vivo benchtop and in vivo acute and survival preclinical models, a new ultrasonic device, Harmonic ACE^®+7 Shears (Harmonic 7), was compared with advanced bipolar devices in sealing vessels 1–7 mm in diameter with respect of burst pressure, seal reliability, and seal durability. Lateral thermal damage and transection time were also evaluated.

Results

Ex vivo tests of Harmonic 7 demonstrated significantly greater median burst pressures than an advanced bipolar device both for vessels <5 mm in diameter (1,078 mmHg and 836 mmHg, respectively, P=0.046) and for those in the range of 5–7 mm (1,419 mmHg and 591 mmHg, P<0.001). In vivo tests in porcine and caprine models demonstrated similar rates of hemostasis between Harmonic 7 and advanced bipolar devices, with high success rates at initial transection and seal durability of 100% after a 30-day survival period.

Conclusion

Sealing 5–7 mm vessels is not a limitation of the type of energy used but of how energy is delivered to tissue. These studies document the ability of ultrasonic energy alone to reliably seal large vessels 5–7 mm in diameter, with significantly greater burst pressure observed in in vitro studies than those observed with an advanced bipolar technology when energy delivery is modulated during the sealing cycle. Furthermore, the seals created in 5–7 mm vessels are shown to be reliable and durable in in vivo preclinical studies.