Emergency laparoscopy

Detection and analysis of the intestinal ischemia using visible and invisible hyperspectral imaging

Intestinal ischemia, or inadequate blood flow to the intestine, is caused by a variety of disorders and conditions. The quickness with which the problem is brought to medical attention for diagnosis and treatment has great effects on the outcome of ischemic injury. Recently, hyperspectral sensors have advanced and emerged as compact imaging tools that can be utilized in medical diagnostics. Hyperspectral imaging provides a powerful tool for noninvasive tissue analyses. In this paper, the hyperspectral camera, with visible and invisible wavelengths, has been evaluated for detection and analysis of intestinal ischemia during surgeries. This technique can help the surgeon to quickly find ischemic tissues. Two cameras, a visible-to-near-infrared camera (400-1000 nm) and an infrared camera (900-1700 nm) were used to capture the hyperspectral images. Vessels supplying an intestinal segment of a pig were clamped to simulate ischemic conditions. A key wavelength range that provides the best differentiation between normal and ischemic intestine was determined from all wavelengths that potentially reduces the amount of data collected in subsequent work. The data were classified using two filters that were designed to discriminate the ischemic intestinal regions.

Measurement of splanchnic photoplethysmographic signals using a new reflectance fiber optic sensor

Splanchnic organs are particularly vulnerable to hypoperfusion. Currently, there is no technique that allows for the continuous estimation of splanchnic blood oxygen saturation (SpO(2)). As a preliminary to developing a suitable splanchnic SpO(2) sensor, a new reflectance fiber optic photoplethysmographic (PPG) sensor and processing system are developed. An experimental procedure to examine the effect of fiber source detector separation distance on acquired PPG signals is carried out before finalizing the sensor design. PPG signals are acquired from four volunteers for separation distances of 1 to 8 mm. The separation range of 3 to 6 mm provides the best quality PPG signals with large amplitudes and the highest signal-to-noise ratios (SNRs). Preliminary calculation of SpO(2) shows that distances of 3 and 4 mm provide the most realistic values. Therefore, it is suggested that the separation distance in the design of a fiber optic reflectance pulse oximeter be in the range of 3 to 4 mm. Preliminary PPG signals from various splanchnic organs and the periphery are obtained from six anaesthetized patients. The normalized amplitudes of the splanchnic PPGs are, on average, approximately the same as those obtained simultaneously from the periphery. These observations suggest that fiber optic pulse oximetry may be a valid monitoring technique for splanchnic organs.

Laparoscopic-assisted Roux-en-Y gastric bypass

Eight patients underwent laparoscopic Roux-en-Y gastric bypass from May 1998 to September 1998 in which a hand-assist technique was used. The operation consisted of a 7.5-cm periumbilical midline incision along with three trocars placed in the upper abdomen. The operative times ranged from 2.25 to 4.5 h. The average preoperative body mass index was 44 kg/m2. Three-month postoperative follow-up revealed an average weight loss of 59 lb. Cosmetic results to date have been excellent even when compared with those of a total laparoscopic operation. The hand-assist technique allows the surgeon to have more control over the most difficult part of the case, which is manipulation of the small bowel in a morbidly obese abdomen.