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

Recurrent laryngeal nerve lymph node dissection with subcomplete sealing using advanced bipolar energy device in minimally invasive esophagectomy

INTRODUCTION

Recurrent laryngeal nerve (RLN) palsy is a complication that must be avoided during esophagectomy. While RLN injury is thought to be caused by thermal spread from electric devices, electric devices are useful to avoid bleeding. When dissecting lymph nodes around RLNs, to seal small vessels, we use subcomplete technique with advanced bipolar. We describe our surgical technique, termed the subcomplete sealing technique, in RLN lymph node dissection.

MATERIALS AND SURGICAL TECHNIQUE

The first step is to perform blunt dissection with forceps on both sides of the esophageal branch near the right RLN. A distance of at least 2 mm from the RLN was preferred. Sealing with advanced bipolar often causes tissue shrinkage, pulling the RLN near the device. To prevent this, sealing should be stopped before reaching completion. Although the sealing was not complete, it was sufficient to seal the small vessels. After subcomplete sealing, the sealed tissues were dissected using laparoscopic scissors. The lymph nodes around left RLN are dissected in the same manner.

DISCUSSION

A total of 76 patients received esophagectomy with the subcomplete technique. Grade IIIa RLN palsy occurred in three cases (3.95%). Over Grade IIIb RLN palsies did not occur. This subcomplete sealing technique can assist surgeons in performing RLN lymph node dissection without bleeding and increasing the rate of RLN palsy.

Evaluation of thermal effects of surgical energy devices: ex vivo study

This study evaluated the direct and indirect thermal effects of various surgical energy devices using an ex-vivo model. Two types of three devices were evaluated: ENSEAL™ X1 Curved Jaw Tissue Sealer (X1) and ENSEAL™ G2 Curved Tissue Sealer (G2) as vessel sealing systems (VSSs), and HARMONIC® HD1000i Shears (HA) as an ultrasonic activating device (USAD). Each device was activated once under DRY or WET conditions. The tissue's maximum temperature (MT), steam MT surrounding the activation site, and steam spread area (SSA) were measured. Under WET conditions, the median MT of a porcine common carotid artery at 1 mm from the activation site by X1, G2, and HA were 84.4, 83.3, and 50.5 °C, respectively. The direct thermal effect of HA was the lowest among the three devices. VSSs showed higher tissue MT under WET conditions compared with DRY conditions. Conversely, USAD showed the opposite trend. G2 demonstrated a significantly higher MT than X1 and HA (P < 0.05). A significant decrease in SSA was observed with decreasing grasping range. In conclusion, VSSs generated higher temperatures than USAD, especially under WET conditions. Surgeons should consider minimizing thermal effects by creating DRY conditions or performing gradual incisions when using VSS devices.

The influence of perivascular tissue on lateral thermal expansion during bipolar vessel sealing

Background

Lateral heat propagation has been an unavoidable effect of bipolar sealing with the risk of damage to surrounding structures. It is presently unknown whether leaving the perivascular tissue in situ may be advantageous in the sense of an isolation effect.

Material and methods

Two groups were formed from ex vivo carotid specimens. Group A (n = 10) consisted of carotid artery with the perivascular connective tissue in place (mean preparation diameter: 10.57 ± 0.16 mm) and group B (n = 10) of skeletonized carotids (mean vessel diameter: 5.21 ± 0.12 mm). All specimens were fixed on a plastic plate and mounted vertically in a holder. Sealing was performed perpendicular to the axis of the specimens. The temperature during the sealing process was recorded by a thermal camera. Group comparison was performed by a nonparametric test and significance was set at p < 0.05.

Results

Mean sealing time in group A was 3.71 ± 0.37 s compared to 3.42 ± 0.37 s (p = 0.009) in group B. The maximum temperature in the middle of the jaws was significantly different. Group A had a temperature of 71.4 ± 3.9 °C and group B had a temperature of 91.4 ± 7.4 °C (p < 0.0001). RILATE risk scores (percent of necrotic zone in relation to potential area of necrosis) at both upper and lower sides of instrumental jaws were significantly different. For group A, it was 14.9 ± 1.6 at the upper side of jaws, 20.4 ± 2.63 at the lower side of jaws and for group B, it was 21.9 ± 3.5 at the upper side of jaws, 30.2 ± 6.2 at the lower side of jaws.

Conclusion

Perivascular connective tissue acts as an insulator with respect to lateral heat propagation. Peak temperature between instrument jaws is significantly reduced with perivascular tissue in situ. This may result in a negative impact on sealing quality.

Endoscopic removal of sinonasal hemangioma using vessel sealing device without tumor embolization

When massive bleeding is anticipated during endoscopic sinonasal tumor removal, a vessel sealing device is useful for successful tumor removal.

Ultrasonic scissors decrease postoperative bleeding complications in mastectomy: A retrospective multicenter cohort study on 728 patients

INTRODUCTION

The aim of this study was to evaluate the rate of postoperative bleeding complications (primary outcome) and any other surgical complications (secondary outcome) in mastectomy between two surgical instruments, ultrasonic SonoSurg® scissors (US) and traditional electrocautery (EC).

MATERIALS AND METHODS

In total 728 patients undergoing mastectomy in two adjacent university hospitals were retrospectively evaluated in terms of postoperative bleeding episodes, surgical site infections, skin flap necrosis, and any reoperations for 30 postoperative days. A propensity score matching was performed to acquire balanced groups. Patients consuming medications affecting hemostasis were excluded from the study. A multivariable logistic regression analysis was conducted to define the odds ratio (OR) for each complication separately. A cost analysis was performed.

RESULTS

The rate of postoperative bleeding complications was significantly lower in patients operated with US (0.3% vs 11.5%, OR 0.020, 95% CI 0.034-0.14) when compared to EC. The rate of surgical site infections (OR 0.65, 95% CI 0.35-1.23) was similar with both instruments, but there were less skin flap necroses (OR 0.35, 95% CI 0.13-0.98) in US group. For any reoperation, the OR for US was 0.13 (95% CI 0.046-0.39), mainly due to the lower number of acute bleeding complications. Even though the US instrument is more expensive than EC, the total cost of the treatment is lower in patients operated with US (3419 vs. 3475 euro).

CONCLUSIONS

US seems to be associated with a lower risk of bleeding complications in mastectomy.

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.

Features and applications of energy devices for prone robot-assisted minimally invasive esophagectomy: a narrative review

BACKGROUND AND OBJECTIVE

Robot-assisted surgery is particularly useful in esophagectomy for esophageal cancer because robotic systems have high-resolution three-dimensional imaging, tremor filtering, and articulated instruments. This review article focuses on the applications and limitations of surgical devices in robot-assisted minimally invasive esophagectomy (RAMIE).

METHODS

A narrative search of Medline was performed for articles published using the keywords "robot-assisted esophagectomy", "technique", "postoperative complication", and "short-term outcomes".

KEY CONTENTS AND FINDINGS

Monopolar scissors: these devices with a sharp tip have an articulating function that allows for fast, sharp dissection without an electrical source. However, scissor-type devices cannot compress the organ, and their hemostatic ability is rather weak. Maryland bipolar forceps: the device has a very thin tip that allows for accurate dissection as well as stronger hemostatic ability by closing the forceps to compress tissues and applying electric current. The disadvantage is longer operation time because the forceps need to be constantly closed and reopened. Long Maryland bipolar grasper: the tip of the long Maryland bipolar grasper is slightly blunt and has the advantage of versatility because it can grip the tissue more delicately. Ultrasonic scalpel: the device can transect tissues speedily without bleeding, shortening operation time, but lacks articulating function. Although thermal spread to the surroundings is relatively narrow, activation time increases with the amount of tissue to be grasped; this raises the temperature above that of the vessel sealer. Vessel sealer: the device is one of the most powerful hemostatic energy devices, based on bipolar electrodes. The articulating jaws on both sides are more suited for sharp transection rather than meticulous dissection because of its powerful hemostatic force and blunt tip. It is also important to note that the vessel sealer produces widespread high-temperature steam. SynchroSeal: the device offers fast activation time, and due to the tip of the device being finely divided, which requires relatively precise manipulation.

CONCLUSIONS

Robot-assisted surgery reduces the limitations of conventional endoscopic surgery by offering stable high-resolution three-dimensional imaging, tremor filtering, and articulated instruments. It is important to understand and exploit the advantages of energy devices suitable for RAMIE.

Intraoperative nerve monitoring during esophagectomy reduces the risk of recurrent laryngeal nerve palsy

BACKGROUND

Despite the risk of recurrent laryngeal nerve (RLN) palsy during esophagectomy, no established method of monitoring RLN injury is currently available.

METHODS

This study included 187 patients who underwent esophagectomy between 2011 and 2018. Among these, intraoperative nerve monitoring (IONM) was done in 142 patients (IONM group), while the remaining 45 patients underwent conventional surgery without IONM (control group). We investigated the incidence of postoperative complications with regard to the use of IONM.

RESULTS

The overall incidence of postoperative RLN palsy was 28% (52/187). The IONM group showed a significantly lower incidence of postoperative RLN palsy as compared to that in the control group (p = 0.004). The overall incidence of postoperative pneumonia was 22% (41/187) in those with Clavien-Dindo (CD) classification beyond grade 2. There were no significant differences between the incidence of any grade of postoperative pneumonia and the use of IONM (p = 0.195 and 0.333; CD > 2 and > 3, respectively). Multivariate analysis demonstrated that tumors in the upper third [odds ratio (OR) 3.12; 95% confidence interval (CI) 1.04-9.29] and lack of IONM use (OR 2.51; 95% CI 1.17-5.38) were independent factors causing postoperative RLN palsy after esophagectomy.

CONCLUSION

IONM helps to reduce the risk of postoperative RLN palsy after esophageal cancer surgery.

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.

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.

Comparative healing of swine skin following incisions with different surgical devices

Background

Electrosurgical technology is widely used in surgical dissection and hemostasis, but the generated heat creates thermal injury to adjacent tissues and delays wound healing. The plasma blade (PB) applies pulsed radiofrequency (RF) to generate electrical plasma along the edge of a thin, flat, insulated electrode, minimizing collateral tissue damage. This study aimed to evaluate wound healing in swine skin following incision with a new surgical system that applies low-temperature plasma (NTS-100), a foreign PB, conventional electrosurgery (ES), and a scalpel blade.

Methods

In vitro porcine skin and an in vivo porcine skin model were used in this study. Full-thickness skin incisions 3 cm in length were made on the dorsum of each animal for each of the 5 surgical procedures at 0, 21, 28, 35, and 42 days. The timing of the surgical procedures allowed for wound-healing data points at 1, 2, 3, and 6 weeks accordingly. Local operating temperature and blood loss were quantified. Wounds were harvested at designated time points, tested for wound tensile strength, and examined histologically for scar formation and tissue damage.

Results

Local operating temperature was reduced significantly with NTS-100 (cut mode 83.12±23.55 °C; coagulation mode 90.07±10.6 °C) compared with PB (cut mode 94.46±11.48 °C; coagulation mode 100.23±6.58 °C, P<0.05) and ES (cut mode 208.99±34.33 °C, P<0.01; coagulation mode 233.37±28.69 °C, P<0.01) in vitro. Acute thermal damage from NTS-100 was significantly less than ES incisions (cut mode: 247.345±42.274 versus 495.295±103.525 µm, P<0.01; coagulation mode: 351.419±127.948 versus 584.516±31.708 µm, P<0.05). Bleeding, histological scoring of injury, and wound strength were equivalent for the NTS-100 and PB incisions.

Conclusions

The local operating temperature of NTS-100 was lower than PB, and NTS-100 had similarly reliable safety and efficacy.

Swine Small Intestine Sealing Performed by Different Vessel Sealing Devices: Ex-Vivo Test

This study aimed to evaluate the sealing quality of swine small intestine using different laparoscopic radiofrequency vessel sealing devices (two 5 mm: RFVS-1 and -2; one 10 mm: RFVS-3) and a harmonic scalpel (HS) compared to golden standard closure technique. The study was divided into two arms. In study arm 1: n = 50 swine intestinal loops (10 per group) were transected with each instrument and the loops in which the devices provided complete sealing, at the gross inspection, were tested for maximum burst pressure (BP) and histological evaluation and compared to an automatic linear stapler. After the BP tests, the devices that achieved significantly lower BP values were excluded from the second arm. The RFVS-1 and -3 provided statistically significant results and were used in study arm 2, to obtain full-thickness biopsies along the antimesenteric border of the loop and were compared with hand-sewn intestinal closure (n = 30; 10 per group). The biopsies were histologically evaluated for thermal injury and diagnostic features, and intestinal loops tested for BP. RFVS-3 achieved comparable results (69.78 ± 4.23 mmHg, interquartile range (IQR) 5.8) to stapler closing technique (71.09 ± 4.22 mmHg, IQR 4.38; p > 0.05), while the RFVS-1 resulted in significantly (p < 0.05) lower BP (45.28 ± 15.23 mmHg, IQR 24.95) but over the physiological range, conversely to RFVS-2 (20.16 ± 7.19 mmHg, IQR 12.02) and HS (not measurable). RFVS-3 resulted not significantly different (p > 0.05) (45.09 ± 8.75 mmHg, IQR 10.48) than Suture (35.71 ± 17.51 mmHg, IQR 23.77); RFVS-1 resulted significantly lower values (23.96 ± 10.63 mmHg, IQR 9.62; p < 0.05). All biopsies were judged diagnostic. Data confirmed that RFVS-1 and -3 devices provided suitable intestinal sealing, with BP pressures over the physiological range. Conversely, the HS and RFVS-2 should not be considered for intestinal sealing. RFVS devices could be employed to obtain small intestine stump closure or full-thickness biopsies. However, further studies should be performed in live animals to assess the role of the healing process.

Repeated partial tissue bite with inadequate cooling time for an energy device may cause thermal injury

BACKGROUND

Over the past three decades, the use of ultrasonically activated device (USAD) and advanced bipolar device (ABD) has grown in minimally invasive surgeries. However, the thermal profile differences during repeated dissection with different grasping ranges of energy devices, which provide valuable information for preventing thermal injury by energy devices, remain unclear.

METHODS

We developed an ex vivo benchtop model to examine the temperature profile of the blade and jaws of two USADs (HARMONIC® ACE + and Sonicision™) and a ABD (Ligasure™ Maryland) with different grasping ranges (partial tissue and full tissue bite) in repeated dissection with minimum cooling time. The maximum temperature, time required for completion to dissection of 10 cm of porcine muscle, thermal spread, and cooling time to reach 60 °C were continuously measured using video thermography. In addition, to evaluate one more grasping range "no tissue", we performed a stress test that activated the USAD without tissue intervention to assess the effects of excessive load on the blade and jaw.

RESULTS

Repeated dissection of energy devices with minimal cooling time results in high blade and jaw temperatures proportional to the incision distance. In particular, the USADs with partial tissue bite showed a significantly higher temperatures at the blade and jaw, longer cooling times, and higher lateral thermal spread than those with a full tissue bite and the ABD. The stress test with a USAD showed an extremely high blade temperature exceeding 400 °C, with the tissue pad melting only 13.2 s after activation.

CONCLUSION

Although USAD with partial tissue bite help ensure precise dissection, repeated long activation with inadequate cooling time may increase the risk of thermal injury during surgery. These results suggest that surgeons should use energy devices properly while understanding the risks of adjacent organ damage that could result from abuse of the device.

Risk factors and therapeutic measures for postoperative complications associated with esophagectomy

Esophageal cancer is one of the most common cancers associated with the high mortality rate. Timely diagnosis and treatment are important to manage the disease and prevent comorbidities. Surgical resection of the tumor and lymph nodes is usually practiced either with or without chemo or chemoradiotherapy. Despite advancements in surgical methods and skills, complex nature of the esophagus and invasiveness of the surgery can lead to serious complications in these patients. In order to predict postoperative outcomes, preoperative examination of the patients, in addition to risk factors, should be conducted. Conclusion: Lastly, early detection of adverse postoperative events may help faster recovery, reduce hospital stay and prevent other morbidities.

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.