Real-time three-dimensional soft tissue reconstruction for laparoscopic surgery.

BACKGROUND: Accurate real-time 3D models of the operating field have the potential to enable augmented reality for endoscopic surgery. A new system is proposed to create real-time 3D models of the operating field that uses a custom miniaturized stereoscopic video camera attached to a laparoscope and an image-based reconstruction algorithm implemented on a graphics processing unit (GPU). METHODS: The proposed system was evaluated in a porcine model that approximates the viewing conditions of in vivo surgery. To assess the quality of the models, a synthetic view of the operating field was produced by overlaying a color image on the reconstructed 3D model, and an image rendered from the 3D model was compared with a 2D image captured from the same view. RESULTS: Experiments conducted with an object of known geometry demonstrate that the system produces 3D models accurate to within 1.5 mm. CONCLUSIONS: The ability to produce accurate real-time 3D models of the operating field is a significant advancement toward augmented reality in minimally invasive surgery. An imaging system with this capability will potentially transform surgery by helping novice and expert surgeons alike to delineate variance in internal anatomy accurately.

Trends in adolescent bariatric surgery evaluated by UHC database collection.

BACKGROUND: With increasing childhood obesity, adolescent bariatric surgery has been increasingly performed. We used a national database to analyze current trends in laparoscopic bariatric surgery in the adolescent population and related short-term outcomes. METHODS: Discharge data from the University Health System Consortium (UHC) database was accessed using International Classification of Disease codes during a 36 month period. UHC is an alliance of more than 110 academic medical centers and nearly 250 affiliate hospitals. All adolescent patients between 13 and 18 years of age, with the assorted diagnoses of obesity, who underwent laparoscopic adjustable gastric banding (LAGB), sleeve gastrectomy (SG), and laparoscopic Roux-en-Y gastric bypass (LRYGB) were evaluated. The main outcome measures analyzed were morbidity, mortality, length of hospital stay (LOS), overall cost, intensive care unit (ICU) admission rate, and readmission rate. These outcomes were compared to those of adult bariatric surgery. RESULTS: Adolescent laparoscopic bariatric surgery was performed on 329 patients. At the same time, 49,519 adult bariatric surgeries were performed. One hundred thirty-six adolescent patients underwent LAGB, 47 had SG, and 146 patients underwent LRYGB. LAGB has shown a decreasing trend (n = 68, 34, and 34), while SG has shown an increasing trend (n = 8, 15, and 24) over the study years. LRYGB remained stable (n = 44, 60, and 42) throughout the study period. The individual and summative morbidity and mortality rates for these procedures were zero. Compared to adult bariatric surgery, 30 day in-hospital morbidity (0 vs. 2.2 %, p < 0.02), the LOS (1.99 ± 1.37 vs. 2.38 ± 3.19, p < 0.03), and 30 day readmission rate (0.30 vs. 2.02 %, p < 0.05) are significantly better for adolescent bariatric surgery, while the ICU admission rate (9.78 vs. 6.30 %, p < 0.02) is higher and overall cost ($9,375 ± 6,452 vs. $9,600 ± 8,016, p = 0.61) is comparable. CONCLUSION: Trends in adolescent laparoscopic bariatric surgery reveal the increased use of sleeve gastrectomy and adjustable gastric banding falling out of favor.

Does type of mesh used have an impact on outcomes in laparoscopic inguinal hernia?

BACKGROUND: Theoretically, a lighter and softer mesh may decrease nerve entrapment and chronic pain by creating less fibrosis and mesh contracture in laparoscopic inguinal hernia repair. METHODS: We performed a telephone survey of patients who underwent laparoscopic inguinal hernia surgery between 2001 and 2007. We recorded patient responses for chronic pain, foreign body sensation, recurrence, satisfaction, and return to work, and then studied the effect of type of mesh (polypropylene vs polyester) on these factors. RESULTS: Of 109 consecutive patients surveyed (mean age, 54.5 y), 67 eligible patients underwent 84 transabdominal extraperitoneal procedures and 2 transabdominal preperitoneal procedures. Patients with polypropylene mesh had a 3 times higher rate of chronic pain (P = .05), feeling of lump (P = .02), and foreign body perception (P = .05) than the polyester mesh group. Our overall 1-year recurrence rate was 5.9%. The recurrence rate was 9.3% for the polypropylene group and 2.9% for the polyester group (P = .26). CONCLUSIONS: A lightweight polyester mesh has better long-term outcomes for chronic pain and foreign body sensation compared with a heavy polypropylene mesh in laparoscopic inguinal hernia repair. We also saw a trend toward higher recurrence in the polypropylene group.

Miniature in vivo robotics and novel robotic surgical platforms.

Robotic surgical systems, such as the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, California), have revolutionized laparoscopic surgery but are limited by large size, increased costs, and limitations in imaging. Miniature in vivo robots are being developed that are inserted entirely into the peritoneal cavity for laparoscopic and natural orifice transluminal endoscopic surgical (NOTES) procedures. In the future, miniature camera robots and microrobots should be able to provide a mobile viewing platform. This article discusses the current state of miniature robotics and novel robotic surgical platforms and the development of future robotic technology for general surgery and urology.

Tool guidance using a compact robotic assistant.

Surgical robots in popular clinical use are generally large machines, which limits their practical use to some extent. This study aims to investigate the potential of a small, table-mounted robot for tool guidance in minimally invasive surgery (MIS). In particular, its multipurpose use for guidance of various tools was investigated. A compact robot capable of manipulating MIS tools was designed and built. The robot can move in four degrees of freedom (DOF): three rotational and one translational. These DOF correspond to motion constrained by a trocar. The robot kinematics are based on a bevel-geared "spherical mechanism," which allows trocar-constrained motion using a small mechanical device. The robot was tested in a porcine model by manipulating scopes and robotic grasping tools using a joystick as directed by a surgeon. Holding a laparoscope, the robot provided superior stability as a camera assistant. It manipulated the scope for visualization of the liver, spleen, bowel, etc. during manual tissue manipulation. Its compactness allowed increased space around the operating table, and the robot was in fact manipulated by joystick from across the room. Maneuvering grasping tools, the robot similarly provided a stable and dexterous platform for tissue manipulation. The test results suggest that the use of robotics for surgery may be enhanced via compact devices to include more hybrid robotic-manual procedures. The robot motion is smoother and more repeatable than that of a human operator. Use of a foot joystick could also place camera control directly with the surgeon. Flexible endoscopes can also be used with the robot for highly dexterous visualization. Notably, changing tools with this system is a very straightforward process and can be achieved without re-registration of the robot's position/orientation. Therefore, combined with other simple robotic tools for grasping, cautery, etc., compact robotic systems based on this technology could replace the large systems in current use, potentially increasing the impact of robots on medical care. This represents an important step towards multifunctional compact surgical robots.