Quantifying inadvertent thermal bowel injury from the monopolar instrument

Comparing a novel wide field of view laparoscope with conventional laparoscope while performing laparoscopic cholecystectomy

BACKGROUND

The limited 70° field of view (FoV) used in standard laparoscopy necessitates maneuvering the laparoscope to view the ports, follow the surgical tools, and search for a target region. Complications related to events that take place outside the FoV are underreported. Recently, a novel laparoscopic system (SurroundScope, 270Surgical) was reported to dramatically expand the FoV from 70 to 270°. This study focuses on differences in performing laparoscopic cholecystectomy using the SurroundScope compared to the standard laparoscope.

METHODS

Forty-four laparoscopic surgeries were performed and video recorded. A subanalysis of 21 Cholecystectomies was performed and compared to 21 Cholecystectomies, performed with the standard laparoscope during the study period by the same surgeon.

RESULTS

No accidental or intraoperative adverse events occurred when using the SurroundScope. Subanalysis of 21 Cholecystectomies revealed shorter fog/smoke cleaning times using the SurroundScope compared to the standard scope (1.45 ± 5.08 sec vs. 54.95 ± 137.77 sec, p = 0.0454). Furthermore, operations performed with the SurroundScope had a shorter trocar placement duration (85.0 ± 40.9 sec vs. 111.3 ± 70.5 sec; p = 0.077), shorter time to achieve critical view of safety (9.5 ± 4.14 min vs. 15.8 ± 11.87 min; p = 0.015), and shorter procedure duration (31.9 ± 10.4 min vs. 42.9 ± 22 min; p = 0.025). In post-operative evaluations, the surgeon noted that tools could be continuously followed and ports were visible without camera manipulation. Also, the surgeon agreed that the procedure could be better planned due to the wide FoV and that surgical workflow was improved. Furthermore, the surgeon agreed that the procedure was safer using the SurroundScope.

CONCLUSIONS

Initial results demonstrate the advantages of the SurroundScope over standard laparoscopy. By expanding the FoV, visualization is improved, the procedure is more efficient, significantly shorter and most important, patient safety, per surgeons' testimonials is improved. Further investigation to quantify these benefits in a larger group of patients and among various surgical procedures should be considered.

Robotic stray energy with constant-voltage versus constant-power regulating electrosurgical generators

INTRODUCTION

Stray energy from surgical energy instruments can cause unintended thermal injuries. There are no published data regarding electrosurgical generators and their influence on stray energy transfer during robotic surgery. There are two approved generators for the DaVinci Xi robotic platform: a constant-voltage regulating generator (cVRG) and a constant-power regulating generator (cPRG). The purpose of this study was to quantify and compare stray energy transfer in the robotic Xi platform using a cVRG versus a cPRG.

METHODS

An ex vivo bovine model was used to simulate a standard multiport robotic surgery. The DaVinci Xi (Intuitive Surgical, Sunnyvale, CA) robotic platform was attached to a trainer box using robotic ports. A 5 s, open-air activation of the monopolar scissors was done with commonly used electrosurgical settings using a cPRG (ForceTriad, Covidien-Medtronic, Boulder, CO) or cVRG (ERBE VIO 300 dV 2.0, ERBE USA, Marietta, GA). Stray energy transfer was quantified as the change in tissue temperature (°C) nearest the tip of the assistance grasper (which was not in direct contact with the active monopolar scissors).

RESULTS

Stray energy transfer occurred with both generators. Utilizing common, comparable settings for standard coagulation, significantly less stray energy was transferred with the cVRG versus cPRG (4.4 ± 1.6 °C vs. 41.1 ± 13.0 °C, p < 0.001). Similarly, less stray energy was transferred using cut modes with the cVRG compared to the cPRG (5.61 ± 1.79 °C vs. 33.9 ± 18.4 °C, p < 0.001).

CONCLUSION

Stray energy transfer increases tissue temperatures more than 45C in the DaVinci Xi robotic platform. Low voltage modalities, such as cut or blend; as well as a cVRG generator, significantly reduces stray energy. Robotic surgeons can minimize the risk of stray energy injuries by using these low risk modes and/or generator.

Detection of adverse events leading to inadvertent injury during laparoscopic cholecystectomy using convolutional neural networks

Uncontrolled movements of laparoscopic instruments can lead to inadvertent injury of adjacent structures. The risk becomes evident when the dissecting instrument is located outside the field of view of the laparoscopic camera. Technical solutions to ensure patient safety are appreciated. The present work evaluated the feasibility of an automated binary classification of laparoscopic image data using Convolutional Neural Networks (CNN) to determine whether the dissecting instrument is located within the laparoscopic image section. A unique record of images was generated from six laparoscopic cholecystectomies in a surgical training environment to configure and train the CNN. By using a temporary version of the neural network, the annotation of the training image files could be automated and accelerated. A combination of oversampling and selective data augmentation was used to enlarge the fully labeled image data set and prevent loss of accuracy due to imbalanced class volumes. Subsequently the same approach was applied to the comprehensive, fully annotated Cholec80 database. The described process led to the generation of extensive and balanced training image data sets. The performance of the CNN-based binary classifiers was evaluated on separate test records from both databases. On our recorded data, an accuracy of 0.88 with regard to the safety-relevant classification was achieved. The subsequent evaluation on the Cholec80 data set yielded an accuracy of 0.84. The presented results demonstrate the feasibility of a binary classification of laparoscopic image data for the detection of adverse events in a surgical training environment using a specifically configured CNN architecture.

Is Hysteroscopy a Good Option to Manage Severe Cesarean Scar Defect?

STUDY OBJECTIVE

To compare the outcomes of hysteroscopic management in women with a severe or nonsevere symptomatic cesarean scar defect (residual myometrium ≤3-mm vs >3-mm, respectively).

DESIGN

Retrospective cohort study.

SETTING

Gynecology department of a teaching hospital.

PATIENTS

Seventy-one women with an operative hysteroscopy for a symptomatic defect (49 with severe defects and 22 with nonsevere ones).

INTERVENTIONS

Operative hysteroscopy for cesarean scar defect in women with a severe defect (residual myometrium ≤3-mm) and with nonsevere defect (residual myometrium >3-mm).

MEASUREMENTS

The main objective was to compare success rates between the 2 groups. The secondary objectives were the comparisons of (1) the number of women who required more than 1 procedure, (2) the rate of complications, (3) the number of subsequent pregnancies, and (4) the evolution of residual myometrium thickness between the groups.

MAIN RESULTS

The success rates were not significantly different between the groups (73.5% in the severe group and 63.6% in the nonsevere group [p = .40]). The number of women requiring more than 1 procedure was also similar, as were the rate of complications and the mean increase of myometrium thickness. The rate of subsequent pregnancies in women who were infertile was significantly higher in women with a severe defect (p = .04).

CONCLUSION

The hysteroscopic approach seems to be a good way to manage cesarean scar defects even when the residual myometrium is thin. A prospective study is, however, necessary to confirm these findings.

Stray energy transfer in single-incision robotic surgery

INTRODUCTION

Stray energy transfer from surgical monopolar radiofrequency energy instruments can cause unintended thermal injuries during laparoscopic surgery. Single-incision laparoscopic surgery transfers more stray energy than traditional laparoscopic surgery. There is paucity of published data concerning stray energy during single-incision robotic surgery. The purpose of this study was to quantify stray energy transfer during traditional, multiport robotic surgery (TRS) compared to single-incision robotic surgery (SIRS).

METHODS

An in vivo porcine model was used to simulate a multiport or single-incision robotic cholecystectomy (DaVinci Si, Intuitive Surgical, Sunnyvale, CA). A 5 s, open air activation of the monopolar scissors was done on 30 W and 60 W coag mode (ForceTriad, Covidien-Medtronic, Boulder, CO) and Swift Coag effect 3, max power 180 W (VIO 300D, ERBE USA, Marietta, GA). Temperature of the tissue (°C) adjacent to the tip of the assistant grasper or the camera was measured with a thermal camera (E95, FLIR Systems, Wilsonville, OR) to quantify stray energy transfer.

RESULTS

Stray energy transfer was greater in the SIRS setup compared to TRS setup at the assistant grasper (11.6 ± 3.3 °C vs. 8.4 ± 1.6 °C, p = 0.013). Reducing power from 60 to 30 W significantly reduced stray energy transfer in SIRS (15.3 ± 3.4 °C vs. 11.6 ± 3.3 °C, p = 0.023), but not significantly for TRS (9.4 ± 2.5 °C vs. 8.4 ± 1.6 °C, p = 0.278). The use of a constant voltage regulating generator also minimized stray energy transfer for both SIRS (0.7 ± 0.4 °C, p < 0.001) and TRS (0.7 ± 0.4 °C, p < 0.001).

CONCLUSIONS

More stray energy transfer occurs during single-incision robotic surgery than multiport robotic surgery. Utilizing a constant voltage regulating generator minimized stray energy transfer for both setups. These data can be used to guide robotic surgeons in their use of safe, surgical energy.

Monopolar stray energy in robotic surgery

INTRODUCTION

Stray energy transfer from monopolar radiofrequency energy during laparoscopy can be potentially catastrophic. Robotic surgery is increasing in popularity; however, the risk of stray energy transfer during robotic surgery is unknown. The purpose of this study was to (1) quantify stray energy transfer using robotic instrumentation, (2) determine strategies to minimize the transfer of energy, and (3) compare robotic stray energy transfer to laparoscopy.

METHODS

In a laparoscopic trainer, a monopolar instrument (L-hook) was activated with DaVinci Si (Intuitive, Sunnyvale, CA) robotic instruments. A camera and assistant grasper were inserted to mimic a minimally invasive cholecystectomy. During activation of the L-hook, the non-electric tips of the camera and grasper were placed adjacent to simulated tissue (saline-soaked sponge). The primary outcome was change in temperature from baseline (°C) measured nearest the tip of the non-electric instrument.

RESULTS

Simulated tissue nearest the robotic grasper increased an average of 18.3 ± 5.8 °C; p < 0.001 from baseline. Tissue nearest the robotic camera tip increased (9.0 ± 2.1 °C; p < 0.001). Decreasing the power from 30 to 15 W (18.3 ± 5.8 vs. 2.6 ± 2.7 °C, p < 0.001) or using low-voltage cut mode (18.3 ± 5.8 vs. 3.1 ± 2.1 °C, p < 0.001) reduced stray energy transfer to the robotic grasper. Desiccating tissue, in contrast to open air activation, also significantly reduced stray energy transfer for the grasper (18.3 ± 5.8 vs. 0.15 ± 0.21 °C, p < 0.001) and camera (9.0 ± 2.1 vs. 0.24 ± 0.34 °C, p < 0.001).

CONCLUSIONS

Stray energy transfer occurs during robotic surgery. The assistant grasper carries the highest risk for thermal injury. Similar to laparoscopy, stray energy transfer can be reduced by lowering the power setting, utilizing a low-voltage cut mode instead of coagulation mode and avoiding open air activation. These practical findings can aid surgeons performing robotic surgery to reduce injuries from stray energy.

Prevention and management of bowel injury during gynecologic laparoscopy: an update

PURPOSE OF REVIEW

The current article aims to briefly review recent literature on bowel injury in gynecologic surgery with a focus on minimally invasive techniques, strategies for prevention, and management of injury.

RECENT FINDINGS

Recent reviews describe a low incidence of bowel injury that is likely affected by low rates of reporting and inconsistent definitions. The major risk factor for bowel injury is adhesive disease, and assessment and prevention techniques for the presence of adhesive disease are evolving. When bowel injury occurs, prompt diagnosis and intraoperative repair yields more favorable outcomes than delayed diagnosis. Repair can be performed by a gynecologic surgeon, with or without the help of a consultant depending on the extent of the injury and surgeon comfort.

SUMMARY

Bowel injury is a potentially catastrophic complication in gynecologic surgery, but its rarity presents a challenge in research. A high index of suspicion and meticulous surgical technique are the cornerstones of managing a bowel injury.

No-touch radiofrequency ablation using multiple electrodes: An in vivo comparison study of switching monopolar versus switching bipolar modes in porcine livers

Objective

To evaluate the in vivo technical feasibility, efficiency, and safety of switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) as a no-touch ablation technique in the porcine liver.

Materials and methods

The animal care and use committee approved this animal study and 16 pigs were used in two independent experiments. In the first experiment, RFA was performed on 2-cm tumor mimickers in the liver using a no-touch technique in the SM mode (2 groups, SM1: 10 minutes, n = 10; SM2: 15 minutes, n = 10) and SB-mode (1 group, SB: 10 minutes, n = 10). The technical success with sufficient safety margins, creation of confluent necrosis, ablation size, and distance between the electrode and ablation zone margin (DEM), were compared between groups. In the second experiment, thermal injury to the adjacent anatomic organs was compared between SM-RFA (15 minutes, n = 13) and SB-RFA modes (10 minutes, n = 13).

Results

The rates of the technical success and the creation of confluent necrosis were higher in the SB group than in the SM1 groups (100% vs. 60% and 90% vs. 40%, both p < 0.05). The ablation volume in the SM2 group was significantly larger than that in the SB group (59.2±18.7 cm³ vs. 39.8±9.7 cm^3,p < 0.05), and the DEM in the SM2 group was also larger than that in the SB group (1.39±0.21 cm vs. 1.07±0.10 cm, p < 0.05). In the second experiment, the incidence of thermal injury to the adjacent organs and tissues in the SB group (23.1%, 3/13) was significantly lower than that in the SM group (69.2%, 8/13) (p = 0.021).

Conclusion

SB-RFA was more advantageous for a no-touch technique for liver tumors, showing the potential of a better safety profile than SM-RFA.

No-Touch Radiofrequency Ablation: A Comparison of Switching Bipolar and Switching Monopolar Ablation in Ex Vivo Bovine Liver

OBJECTIVE

To evaluate the feasibility, efficiency, and safety of no-touch switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) using ex vivo bovine livers.

MATERIALS AND METHODS

A pork loin cube was inserted as a tumor mimicker in the bovine liver block; RFA was performed using the no-touch technique in the SM (group A1; 10 minutes, n = 10, group A2; 15 minutes, n = 10) and SB (group B; 10 minutes, n = 10) modes. The groups were compared based on the creation of confluent necrosis with sufficient safety margins, the dimensions, and distance between the electrode and ablation zone margin (DEM). To evaluate safety, small bowel loops were placed above the liver surface and 30 additional ablations were performed in the same groups.

RESULTS

Confluent necroses with sufficient safety margins were created in all specimens. SM RFA created significantly larger volumes of ablation compared to SB RFA (all p < 0.001). The DEM of group B was significantly lower than those of groups A1 and A2 (all p < 0.001). Although thermal injury to the small bowel was noted in 90%, 100%, and 30% of the cases in groups A1, A2, and B, respectively, full depth injury was noted only in 60% of group A2 cases.

CONCLUSION

The no-touch RFA technique is feasible in both the SB and SM modes; however, SB RFA appears to be more advantageous compared to SM RFA in the creation of an ablation zone while avoiding the unnecessary creation of an adjacent parenchymal ablation zone or adjacent small bowel injuries.