Safety assessment of the use of ultrasonic energy in the proximity of the recurrent laryngeal nerve in a porcine model

Efficacy and Safety Evaluation of Energy Devices in Bench Surgery for Pancreas Transplantation

INTRODUCTION

Bench surgery for the preparation of deceased donor pancreatic grafts is labor-intensive and time-consuming. We hypothesized that energy devices could be used during bench surgery to decrease the bench surgery time. However, because bench surgery has two unique characteristics, wet conditions and no blood flow in the vessels, it is necessary to verify the safety and efficacy under such conditions.

METHODS

In an animal tissue model, we validated both ultrasonic and bipolar energy devices: Harmonic Shears and the LigaSure (LS) vessel-sealing device by evaluating heat spread and pressure resistance under bench surgery conditions. In a clinical evaluation of the LS, we compared the outcomes of 22 patients in two different bench surgery groups: with and without the use of the LS.

RESULTS

Clinically, the bench surgery time was significantly shorter in the LS group than that in the conventional group (P < 0.001). In the animal tissue experiments, the highest temperature in bench surgery conditions was 60.4°C after 1 s at a 5-mm distance in the LS group. Pressure resistance of ≥ 750 mmHg was achieved in almost all trials in both veins and arteries, with no difference between Harmonic Shears and LS. There was more surgical smoke visually in bench conditions versus in dry conditions and under half bite versus full bite conditions.

CONCLUSIONS

The encouraging results of our exploratory clinical and animal studies of the energy devices suggest that they may be useful in the setting of bench surgery.

Comparison of perioperative outcomes between bipolar sealing, ultrasonic shears and a hybrid device during laparoscopic gastrectomy for early gastric cancer: a prospective, multicenter, randomized study

BACKGROUND

Although EBDs are essential for minimally invasive surgery, well-established prospective randomized studies comparing EBDs are scarce. This study aimed to compare the intraoperative inflammatory response and short-term surgical outcomes among different energy-based devices (EBDs) in laparoscopic distal gastrectomy (LDG).

METHODS

Patients with clinical stage I gastric cancer scheduled for LDG at two different medical centers were prospectively randomized into three groups: ultrasonic shears (US), advanced bipolar (BP) and ultrasonic-bipolar hybrid (HB). The C-reactive protein (CRP) level, operation time, intraoperative blood loss (IBL), laboratory tests, cytokines (interleukin (IL)-6 and IL-10), hospital stay, and complication rate were analyzed. A novel semiquantitative measurement method using indocyanine green (ICG) and a near-infrared camera measured the amount of lymphatic leakage.

RESULTS

The primary endpoint, the CRP level, was significantly lower in the BP (n = 60) group than in the US (n = 57) or HB (n = 57) group [9.03 ± 5.55 vs. 11.12 ± 5.02 vs. 12.67 ± 6.14, p = 0.001, on postoperative day (POD) 2 and 7.48 vs. 9.62 vs. 9.48, p = 0.026, on POD 4]. IBL was significantly lower in BP than in US or HB (26.3 ± 25.3 vs. 43.7 ± 42.0 vs. 34.9 ± 37.0, p = 0.032). Jackson-Pratt drainage triglycerides were significantly lower in BP than in US (53.6 ± 33.7 vs. 84.2 ± 59.0, p = 0.11; HB: 71.3 ± 51.4). ICG fluorescence intensity, operation time, laboratory results, cytokines, hospital stay, and complication rate were not significantly different among the 3 groups.

CONCLUSION

BP showed a lower postoperative CRP level and less IBL than US and HB, suggesting less collateral thermal damage and better sealing function. Surgeons may consider this when selecting EBDs for laparoscopic surgery.

Delayed tracheal rupture following transoral endoscopic thyroidectomy vestibular approach: Case report and review of the literature

BACKGROUND

Although the transoral endoscopic thyroidectomy vestibular approach (TOETVA) has been proven to be a safe procedure for select patients, as it is a novel approach, all associated complications require adequate attention.

METHODS

We presented a 49-year old woman who underwent TOETVA developed delayed tracheal rupture 1 week after surgery. An extensive search of literature was carried out using PubMed, Embase, and Web of Science for studies reporting tracheal injury following endoscopic thyroidectomy.

RESULTS

Thirteen cases of endoscopic thyroidectomy were analyzed, including eight cases of TOETVA. Tracheal injury occurred during various procedures, including accidental dissection, surgical needle puncture, Hegar dilation and trocar placement, and thermal injury by the energy device.

CONCLUSIONS

Tracheal injury following TOETVA is an underreported complication that can be induced by various factors. Thermal injury to the trachea is more likely to cause a delayed rupture. Careful blunt dissection and standardized use of energy devices are suggested.

Effects of Intraoperative Neural Tunnel in Protecting Recurrent Laryngeal Nerve: Experiences in Open, Trans Breast, and Transoral Endoscopic Thyroidectomy

Background

Energy-based devices (EBDs) increase the risks of thermal nerve injuries. This study aimed to introduce a surgical strategy of intraoperative neural tunnel protecting (INTP) for evaluating the effect in reducing the incidence of recurrent laryngeal nerve (RLN) damage in open, trans breast, and transoral endoscopic thyroidectomy.

Methods

INTP strategy was introduced: a tunnel was established and protected by endoscopic gauze along the direction of the nerve. A total of 165, 94, and 200 patients with papillary thyroid carcinoma (PTC) were to use INTP in respectively open, trans breast, and transoral endoscopic thyroidectomy as the INTP group. Additionally, 150, 95, and 225 patients who received the same methods without INTP were enrolled in the control group. Ipsilateral thyroidectomy or total thyroidectomy, and central compartment dissection were performed on the enrolled patients.

Results

Clinicopathologic characteristics, surgical outcomes, and surgical complications were similar between the INTP group and the control group in open, trans breast, and transoral endoscopic thyroidectomy. The incidences of electromyography (EMG) changes in the INTP group were lower as compared to the control group in trans breast endoscopic thyroidectomy (p < 0.05). The incidence of postoperative hoarse in the INTP group was lower as compared to the control group in open and transoral endoscopic thyroidectomy (p < 0.05). Postoperative calcium levels (p < 0.01) were significantly higher, and the white blood cells (p < 0.05) and C-reactive protein levels (p < 0.01) were significantly decreased in the INTP group compared with the control group in transoral endoscopic thyroidectomy.

Conclusions

This was the first instance of the INTP strategy being introduced and was found to be an effective method for protecting the RLN in open, trans breast, and transoral endoscopic thyroidectomy. Additionally, INTP helped protect other important tissues such as the parathyroid glands in transoral endoscopic thyroidectomy as well as in reducing postoperative inflammatory responses.

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

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

Hyperthermal liquid, spray, and smog may be potential risk factors for recurrent laryngeal nerve thermal injury during thyroid surgeries

PURPOSE

The hyperthermal liquid, spray and smog caused by energy-based surgical devices (EBDs) may be the potential risk factors for recurrent laryngeal nerve (RLN) thermal injury, but not been reported previously. We aim to demonstrated it both in thyroid surgeries and animal experiments.

METHODS

321 thyroid patients and 32 rats were divided into two groups respectively. A type of endoscopic gauze was implemented in the protected group to prevent nerve from thermal risks. Electromyography and laryngoscope were recorded to determine nerve's conductive ability. Microstructural morphological damage to nerves and muscles were evaluated by light and electron microscopy in the animal experiments.

RESULTS

After thyroid surgeries, the incidence of transient vocal cord (VC) palsy was decreased in the protected group (1.4%) compared with the conventional group (4.7%) (P = 0.037). In animal experiments, the average nerve conductive velocity was significantly decreased in the conventional group (5.8 ± 2.1 vs. 25.5 ± 4.7 m/s, P < 0.01). Typical acute morphological thermal changes of edema, coagulation and homogenization in nerve tissues were recorded by light microscopy in the conventional group. Four weeks later, the average weight of gastrocnemius muscles in the injured limb was significantly decreased (1.3 ± 0.2 vs. 2.2 ± 0.2 g, P < 0.01), while no significant difference was noted in the protected group (2.0 ± 0.3 vs. 2.3 ± 0.4 g, P = 0.61).

CONCLUSIONS

Hyperthermal liquid, spray or smog may represent risk factors contributing to RLN thermal injury caused by EBDs. Damage to the nerve's conductive ability and morphological changes in nerves and muscles likely represent typical responses to thermal injury. Implementation of endoscopic gauze may be a promising method to protect the RLN from thermal damage especially in endoscopic thyroid surgeries.

Clinical observation of end-to-end neuroanastomosis in the treatment of complete injury of the unilateral recurrent laryngeal nerve

Background

Complete injury of the recurrent laryngeal nerve (RLN) is a serious complication of thyroid surgery. Increasingly researches focus on the voice recovery of patients with RLN injury. This paper studied the effect of immediate end-to-end neuroanastomosis after complete injury of the unilateral RLN during thyroid surgery on postoperative vocal function.

Methods

Thirteen patients who underwent end-to-end neuroanastomosis for the treatment of complete injury of the unilateral RLN caused by thyroid surgery in Hunan Provincial People's Hospital between October 2009 and January 2020 were selected. The basic information, cause of RLN injury, postoperative voice recovery, recovery time, and subjective assessment of voice by auditory perception results (Grade, Roughness, Breathiness, Asthenia, and Strain, the GRBAS score) of the patients were recorded.

Results

Among the 13 cases with RLN injury, the cause of RLN injury in 10 cases was transection by sharp instruments, and the voice was recovered one day after the operation. The cause of RLN injury in one case was suture of the RLN branch, and the voice was recovered one day after the operation. The cause of RLN injury in two cases was thermal injury, and the times for voice recovery after end-to-end neuroanastomosis were 3 and 4 months. The patients with a GRBAS score of 0 or 1 recovered their voice one day after the operation. The GRBAS score reached 1 in the two thermal injury cases, with voice recovery at 3 and 4 months after surgery. By 6 months, the voice recovery rate of the patients was 100%.

Conclusions

After complete injury of the unilateral RLN, immediate end-to-end anastomosis of the RLN can maximally preserve the postoperative vocal function of patients.

Safety Profile of the New Harmonic Focus: Different Emissivity and Temperature Behavior Between the Active and the Inactive Blade

Ultrasonic devices disperse less energy in the tissues. The new Harmonic Focus+ (HF+) seems to be more efficient but thermal damages have been reported. This study examined the temperature and the emissivity profile of the active and passive blades of the HF+, on a pig tissue model at different power settings. The FLIR System B series thermal imaging camera has been used on various biological pig tissues to evaluate the emissivity of the ultrasonic device. The active blade heats up faster than the passive one and the increase in power increases the speed of the temperature raising only on the active blade. Increasing the power setting reduces the dissection time and the temperature of both blades. Active blade temperatures of <60°C are obtained with cutting times close to 5 seconds; with these cutting times, the inactive blade does not exceed 30°C. The HF+ emissivity profiles demonstrate that the behavior of the inactive blade is significantly different from the active one. To prevent thermal damages, keep the active blade toward the operator, do not exceed 5 seconds of activation, use the maximum power, and avoid the use of the instrument as a dissector immediately after its activation.

Comparison of hypocalcemia rates between LigaSure and clamp-and-tie hemostatic technique in total thyroidectomies

BACKGROUND

Postoperative hypocalcemia (PH) is a serious complication after total thyroidectomy. This study aimed to compare PH rates between LigaSure Small Jaw (LSJ) and clamp-and-tie hemostatic technique in patients undergoing total thyroidectomy.

METHODS

Four hundred twenty patients were divided into two groups: group L (210 patients) performed with LSJ and group C (210 patients) with clamp-and-tie technique. Serum ionized calcium (iCa) was measured before and 12, 24, 48, 72 hours after surgery. PH was defined as iCa lower than 4.2 mg/dL in at least two measurements.

RESULTS

There was no significant difference between groups in sex, age, extent of surgery, pathology, and the strategy of intraoperative management of parathyroid glands (PG). The PH rate was significantly lower in group L compared to group C (22.9% vs 32.4%, P = .03).

CONCLUSIONS

Compared to clamp-and-tie technique, LigaSure is superior to decrease PH rate after total thyroidectomy.

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.

Assessment of the Safety of the New Hybrid Pencil Type Energy (NP) Device Used Close to the Recurrent Laryngeal Nerve in a Porcine Model: Comparison With a Conventional Electrosurgical Knife

BACKGROUND

Recurrent laryngeal nerve (RLN) paralysis is mainly associated with esophagectomy, and it may result in not only other morbidities, such as aspiration pneumonia, but also in long-term issues. Therefore, an approach to prevent RLN paralysis is necessary. The present study was designed to determine the technical usability of the new hybrid pencil type energy (NP) device developed by Olympus Corporation (Tokyo, Japan) and compare it with a conventional electrosurgical knife (EK) for resection around the RLN lymph nodes.

METHODS

This nonsurvival (acute) study included 10 pigs (20 RLNs) and investigated the threshold for thermal RLN damage with the NP device and a conventional EK. To obtain basic information for our study, a preliminary experiment for heat spread was performed.

RESULTS

When using the EK device, the amplitude value disappeared at a distance of 1 mm from the RLN, but when using the NP device, the amplitude value was maintained up to a distance of 0.5 mm. There were significant differences at distances of 0 mm, 0.5 mm, and 1 mm between the NP and EK devices. Furthermore, heat spread was lower with the NP device than with the EK device.

CONCLUSIONS

The new energy device developed by Olympus Corporation was found to be technically safe for resection of the RLN lymph nodes in a porcine model. To the best of our knowledge, this is the first study to demonstrate the potential advantages of using this new energy device in a clinical aspect.

Thermal effects of the Thunderbeat™ device on the recurrent laryngeal nerve during thyroid surgery

PURPOSE

To investigate the safety of the Thunderbeat^™ (TB) device in thyroid surgery by clarifying its thermal effects on the recurrent laryngeal nerve (RLN).

METHODS

We performed thyroidectomy using TB on four female pigs under general anesthesia. TB was applied 0, 1, and 2 mm from the RLN. The effects of incisions made in tissues in the vicinity of the RLN were evaluated by intraoperative neuromonitoring and pathological examination.

RESULTS

The value of the neural integrity monitor (NIM) was unchanged at 2 and 1 mm, but there was loss of signal at 0 mm. The differences between 2 and 0 mm were not clear from the pathological findings.

CONCLUSIONS

When using the TB device during thyroid surgery, it is recommended that it is visually kept from making any contact with the RLN.

Neural monitoring represent central safety asset for new technologies in thyroid surgery in translational protocols

Commentary on the published paper by Chávez KV, Barajas EM, Soroa F, Gamboa-Dominguez A, Ordóñez S, Pantoja JP, Sierra M, Velázquez-Fernández D, Herrera MF. Safety assessment of the use of ultrasonic energy in the proximity of the recurrent laryngeal nerve in a porcine model. Am J Surg. 2018 Jan;215(1):186-190. doi: 10.1016/j.amjsurg.2017.04.013. Epub 2017 Jun 7. PubMed PMID: 28622836.