Endoscopic and robotic surgery in the neck: Experimental and clinical applications

Endo-robotic resection of the submandibular gland in a cadaver model

BACKGROUND

By means of a prospective, nonrandomized investigation, we evaluated the feasibility of performing endo-robotic resection of the submandibular gland in a cadaver model and compared the results of robotically enhanced endoscopic surgery with those from a conventional endoscopic technique.

METHODS

Procedural times were recorded in a consecutive series of 11 endoscopic submandibular gland resections using the daVinci Surgical System (Intuitive Surgical, Sunnyvale, CA) and a modified endoscopic surgical approach previously developed in a porcine model. The presence of neurovascular injury was assessed postoperatively, and the specimens were examined histologically.

RESULTS

Eleven endo-robotic submandibular gland resections were successfully performed in six cadavers (no conversions to open resection were necessary). The median duration of the procedures was 48 minutes (range, 33-82 minutes). Creation of the operative pocket took an average (+/-SD) of 12.2 +/- 5.3 minutes, assembly of the robot required 9.3 +/- 4.1 minutes, and the mean time for submandibular gland resection was 29.4 +/- 8.9 minutes. The time required for robotic assembly was offset by the reduced operative time necessary compared with conventional endoscopic resection. Histologic examination confirmed the presence of normal glandular architecture, without evidence of excessive mechanical or thermal injury. There were no cases of apparent neurovascular injury.

CONCLUSIONS

Robotically enhanced endoscopic surgery in the neck is feasible and offers a number of compelling advantages over conventional endoscopic neck surgery. Clinical trials will be necessary to determine whether these advantages can be achieved in clinical practice.

Prospective evaluation of endoscopic approaches to the thyroid compartment

OBJECTIVE

To compare a number of endoscopic approaches to the thyroid compartment.

DESIGN

Prospective, nonrandomized, experimental investigation in a porcine model.

METHODS

We performed a consecutive series of 13 endoscopic thyroidectomies using 5 distinct approaches. The procedures differed by the direction of the approach, incision placement, and use of facilitative maneuvers. The parameters assessed included procedure duration, estimated blood loss, heart rate, blood pressure, temperature, oxygen saturation, and arterial blood gas levels. The thyroid specimens were weighed and examined histologically.

RESULTS

Four of the endoscopic approaches were successfully used for resection of the thyroid (12 of 13 animals). The mean operative times were as follows: superior approach (n = 4), 47 +/- 14.6 minutes; lateral axillary approach (n = 4), 67 +/- 11.8 minutes; and superficial axillary (n = 3), 67.7 +/- 22.3 minutes. The one axillary approach took 84 minutes. The precordial approach (n = 1) lasted 47 minutes and then required open conversion. The overall median estimated blood loss was 0 (range 0-100) mL. The mean change in blood pressure and pH from the beginning to the end of the procedure was -0.5 +/- 24.1 mm Hg and 0.16 +/- 0.07, respectively. The thyroid glands weighed 4.3 +/- 0.9 g and had normal glandular architecture with no evidence of significant tissue trauma or thermal injury. There were no cases of pneumothorax, subcutaneous emphysema, or air embolism.

CONCLUSION

A number of approaches to the thyroid compartment are conceivable. The superior approach proved to be the fastest and easiest, whereas the lateral axillary and superficial axillary were the best approaches from a cosmetic and clinical standpoint.

Surgical robotics in otolaryngology: expanding the technology envelope

PURPOSE OF REVIEW

Surgical robotics arose as an extension of virtual reality and robotic technology developed by the United States Department of Defense. Current surgical robotic systems have been used to perform a variety of minimally invasive surgical procedures.

RECENT FINDINGS

The Food and Drug Administration recently granted approval for the clinical use of two surgical robotic systems. Laboratory and clinical experience suggests that the use of surgical robotics is associated with some distinct advantages and disadvantages when compared with conventional open procedures. Robotic surgery has recently been described in the head and neck, and as a result the otolaryngologist should have a basic understanding of the potential applications of surgical robotics in head and neck surgery.

SUMMARY

Surgical robotic technology is evolving but appears to have a distinct place in the surgical armamentarium.

Endoscopic Neck Surgery: Resection of the Submandibular Gland in a Cadaver Model

OBJECTIVES/HYPOTHESIS

The objective was to evaluate the feasibility of performing a totally endoscopic resection of the submandibular gland in a cadaver model.

STUDY DESIGN

Prospective, nonrandomized experimental investigation in a cadaver model.

METHODS

A modified endoscopic surgical approach (representing a hybrid of balloon dissection and low-pressure carbon dioxide insufflation) previously developed in a porcine model was implemented in fresh cadavers. Once a reliable protocol was achieved, eight procedures were performed in six cadavers. Data collected prospectively included the operative time, inadvertent neurovascular injury, and size of the glands.

RESULTS

All eight endoscopic submandibular gland resections were successfully performed in six consecutive cadavers (no conversions to open resection were necessary). The duration of the procedures ranged from 50 to 150 minutes, with a median duration of 65.5 minutes and a steady trend toward a shorter duration. Histological examination confirmed the presence of normal glandular architecture without evidence of excessive trauma or thermal injury. The optimal spacing of the instrument ports was 4 cm from the camera port. There were no cases of neurovascular injury. In two cadavers, a minimal amount of subcutaneous emphysema could be appreciated, which was limited to the skin overlying the dissection.

CONCLUSION

Totally endoscopic resection of the submandibular gland is possible by combining balloon dissection with low-pressure carbon dioxide insufflation. The excellent visualization afforded by the endoscope provided a safe operative approach. Ultimately, a number of endoscopic neck procedures may be possible, and clinical trials are under way.

Surgical robotic applications in otolaryngology

OBJECTIVES

To explore the feasibility of performing endo-robotic neck surgery in a porcine model and to compare the results of robotically enhanced endoscopic surgery with those from a conventional endoscopic technique.

STUDY DESIGN

Prospective, nonrandomized experimental investigation in a porcine model.

METHODS

We performed a consecutive series of endoscopic neck surgeries using the daVinci surgical system (Intuitive Surgical Inc.). The length of time required to establish the operative pocket and to assemble the robotic components, as well as the total duration of each operation, was recorded. The animals were continuously monitored for heart rate, blood pressure, and end-tidal CO(2) pressure, and evaluation for presence of pneumothorax and subcutaneous emphysema was undertaken postoperatively. The specimens were examined histologically.

RESULTS

Four different types of neck surgery were successfully performed on both sides of the neck of four animals using the daVinci surgical system. Creation of the operative pocket took, on average (+/-SD), 18.1 +/- 11.9 minutes, and assembly of the robot required 12.5 +/- 9.9 minutes, resulting in a mean preparation time for all procedures of 30.6 +/- 21.0 minutes. The mean operative time for submandibular resection (n = 3) was 19.0 +/- 6.6 minutes, with a total procedure time of 39.0 +/- 10.2 minutes. Selective neck dissections (n = 3) required a mean operative time of 66.0 +/- 18.5 minutes and a total procedure time of 85.7 +/- 16.7 minutes. One partial parotidectomy and one thymectomy were also performed. The median estimated blood loss was 0 mL (range, 0-10 mL). The end-tidal CO(2) pressure fell from the start to the end of the procedures by a mean of 4.4 +/- 7.9 mm Hg. The blood pressure fell by a mean of 1.9 +/- 7.5 mm Hg. There was one case of modest subcutaneous emphysema, and there were no cases of pneumothorax or air embolism. No conversions to open resection were necessary.

CONCLUSIONS

Robotically enhanced endoscopic surgery in the neck is feasible and offers a number of compelling advantages over conventional endoscopic neck surgery. Clinical trials will be necessary to determine whether these advantages can be achieved in clinical practice.