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Sang W Lee

Publications and source records attributed to Sang W Lee.

2 recordsLinked to original sources

Laparoscopic vs. hand-assisted laparoscopic sigmoidectomy for diverticulitis.

INTRODUCTION: Sigmoid colectomy for diverticulitis can be technically challenging because of severe inflammation in the left-lower quadrant and pelvis. We hypothesized that hand-assisted laparoscopic technique may facilitate laparoscopic completion of this surgery while retaining the short-term benefits associated with "pure" laparoscopic surgery, in which an incision is made only for extracting the specimen. This study was designed to compare the outcomes of patients who underwent totally laparoscopic or hand-assisted laparoscopic sigmoidectomy for diverticulitis. METHODS: We reviewed our prospectively collected patient database from July 2001 to June 2004 and compared the intraoperative data and postoperative outcomes of patients who underwent elective laparoscopic or hand-assisted laparoscopic sigmoidectomies for diverticulitis. Complicated patients (with abscess or fistulas) also were separately analyzed. RESULTS: The hand-assisted laparoscopic (mode age, 57 years; 48 percent male) and laparoscopic sigmoidectomy (mode age, 56 years; 90 percent male) groups were similar with regard to age and gender. Overall, patients who underwent laparoscopic (n = 21) vs. hand-assisted laparoscopic (n = 21) sigmoidectomies had a significantly longer operative time (197 +/- 42 vs. 171 +/- 34 minutes, P = 0.04) and shorter incision length (5 +/- 2.1 vs. 9.3 +/- 4.1 cm, P = 0.0001). Patients with complicated diverticulitis (n = 14; abscess, colovesical fistula, enterocolic fistula) who underwent laparoscopic sigmoidectomies (n=4) had a significantly longer operative time compared with hand-assisted laparoscopic sigmoidectomy (n = 10) group (255 +/- 18 vs. 177 +/- 34 minutes, P = 0.001). Conversion rate for the laparoscopic group was significantly higher (3/4 vs. 1/10, P = 0.04, Fisher exact) when complicated diverticulitis was present. There were no differences in postoperative outcomes or incision lengths in the complicated group. CONCLUSIONS: Outcomes after hand-assisted laparoscopic sigmoidectomy for diverticulitis are similar to those seen in the pure laparoscopic method, with lower conversion rates and shorter operative times. Hand-assisted laparoscopic sigmoid resection for diverticulitis is an attractive alternative to a "pure" laparoscopic method in complicated cases.

Adult↗

Multiview registration of 3D scenes by minimizing error between coordinate frames.

This paper addresses the problem of large-scale multiview registration of range images captured from unknown viewing directions. To reduce the computational burden, we separate the local problem of pairwise registration on neighboring views from the global problem of distribution of accumulated errors. We define the global problem as an optimization over the graph of neighboring views, and we show how the graph can be decomposed into a set of cycles such that the optimal transformation parameters for each cycle can be solved in closed form. We then describe an iterative procedure that can be used to integrate the solutions for the set of cycles across the graph of views. This method for error distribution does not require point correspondences between views, and can be used to integrate any method of pairwise registration or robot odometry.

Algorithms↗