Robotic surgery and limitations

Development and testing of a grasper for NOTES powered by variable stiffness pneumatic actuation

BACKGROUND

In natural orifice transluminal endoscopic surgery (NOTES) the peritoneal cavity is reached through natural orifices (mouth, rectus and transvaginal duct), by means of little cuttings in the walls of hollow organs. Due to narrow spaces, NOTES needs robotic systems to assure operation/movement precision and patient safety. Variable stiffness actuation (VSA) assures both requirements.

METHODS

The authors developed a grasper for NOTES, provided with VSA, to use as an end-effector for snail robot devices. The present paper deals with basic concepts of VSA and describes the design and architecture of the grasper. Characterization and functional experiments were performed and results analysed.

RESULTS

A finite element model developed for the actuator design was validated, performance grasper characteristic curves were obtained, VSA was validated, and the gripping capability of several objects was assessed.

CONCLUSION

The grasper satisfies technical design specifications. On the basis of the results obtained, a control system can be developed to test grasper in a simulated surgery environment.

The first nationwide evaluation of robotic general surgery: a regionalized, small but safe start

BACKGROUND

The purpose of this study was to evaluate the outcomes of the most commonly performed robotic-assisted general surgery (RAGS) procedures in a nationwide database and compare them with their laparoscopic counterparts.

METHODS

The Nationwide Inpatient Sample was queried from October 2008 to December 2010 for patients undergoing elective, abdominal RAGS procedures. The two most common, robotic-assisted fundoplication (RF) and gastroenterostomy without gastrectomy (RG), were individually compared with the laparoscopic counterparts (LF and LG, respectively).

RESULTS

During the study, 297,335 patients underwent abdominal general surgery procedures, in which 1,809 (0.6 %) utilized robotic-assistance. From 2009 to 2010, the incidence of RAGS nearly doubled from 573 to 1128 cases. The top five RAGS procedures by frequency were LG, LF, laparoscopic lysis of adhesions, other anterior resection of rectum, and laparoscopic sigmoidectomy. Eight of the top ten RAGS were colorectal or foregut operations. RG was performed in 282 patients (0.9 %) and LG in 29,677 patients (99.1 %). When comparing RG with LG there was no difference in age, gender, race, Charlson comorbidity index (CCI), postoperative complications, or mortality; however, length of stay (LOS) was longer in RG (2.5 ± 2.4 vs. 2.2 ± 1.5 days; p < 0.0001). Total cost for RG was substantially higher ($60,837 ± 28,887 vs. $42,743 ± 23,366; p < 0.0001), and more often performed at teaching hospitals (87.2 vs. 50.9 %; p < 0.0001) in urban areas (100 vs. 93.0 %; p < 0.0001). RF was performed in 272 patients (3.5 %) and LF in 7,484 patients (96.5 %). RF patients were more often male compared with LF (38.2 vs. 32.3 %; p < 0.05); however, there was no difference in age, race, CCI, LOS, or postoperative complications. RF was more expensive than LF ($37,638 ± 21,134 vs. $32,947 ± 24,052; p < 0.0001), and more often performed at teaching hospitals (72.4 vs. 54.9 %; p < 0.0001) in urban areas (98.5 vs. 88.7 %; p < 0.0001).

CONCLUSIONS

This nationwide study of RAGS exemplifies its low but increasing incidence across the country. RAGS is regionalized to urban teaching centers compared with conventional laparoscopic techniques. Despite similar postoperative outcomes, there is significantly increased cost associated with RAGS.