Fluorescein-assisted laparoscopy in the identification of arterial mesenteric ischemia

Acute mesenteric ischemia: diagnostic approach and surgical treatment

Mortality related to acute mesenteric arterial occlusion remains very high. Patient survival is dependent on prompt recognition and revascularization before ischemia progresses to intestinal gangrene. Biphasic computed tomography angiography has surpassed angiography as the diagnostic test of choice due to its ability to define the arterial anatomy and to evaluate secondary signs of mesenteric ischemia. Unlike chronic mesenteric ischemia, the treatment of acute arterial mesenteric ischemia, either embolic or thrombotic, remains largely surgical. This is due to the emergent need for revascularization combined with a careful evaluation of the intestines. Endovascular techniques remain useful, however, and can save precious time in the treatment of these challenging patients if integrated into a treatment pathway combined with definitive surgical treatment. A new hybrid endovascular-surgical treatment for the treatment of acute mesenteric thrombosis is described.

Laparoscopic Diagnostics of Acute Bowel Ischemia Using Ultraviolet Light and Fluorescein Dye: An Experimental Study

PURPOSE

The aim of the study was to show the diagnostic potential of laparoscopy using fluorescein dye and ultraviolet light in acute bowel ischemia.

MATERIALS AND METHODS

The study involved 12 domestic pigs. Under general anesthesia, the peripheral branch of the superior mesenteric artery was embolized using polyvinyl-alcohol microparticles. Two hours after the embolization, optical filters were placed into the laparoscopic set to produce ultraviolet light. Fluorescein dye was given intravenously, and the bowel was inspected. Clips were placed on the border of the ischemia that was visualized with fluorescein. Resection of the ischemic part of the bowel and anastomosis of the viable parts were carried out using laparoscopic linear cutting staplers. After 24 hours, a laparoscopic second-look procedure was carried out to verify the viability of the anastomosis.

RESULTS

The method was in all cases able to recognize intestinal ischemia and reliably differentiate ischemic bowel segments from viable bowel. Microscopic analysis of the ischemic specimens showed beginning ischemic changes of the bowel tissues.

CONCLUSIONS

The method should be considered a valuable diagnostic procedure both for diagnostics of early stage of acute bowel ischemia and for second-look procedures.

Laparoscopic evaluation of intestinal ischemia using fluorescein and ultraviolet light in a porcine model

BACKGROUND

The laparoscopic use of fluorescein and ultraviolet light may be a useful diagnostic tool that potentially could reduce the time until diagnosis and the subsequent mortality of mesenteric ischemia.

METHODS

Eight pigs were subjected to a pneumoperitoneum pressure of 7 mmHg, and another eight pigs were exposed to a pressure of 14 mmHg. A segment of small bowel was devascularized. Two filters were used to create ultraviolet light. Pigs from each pressure group were given various intravenous fluorescein doses. The ischemic segment of the small intestine and other structures were inspected laparoscopically with the filters attached. A videotape was evaluated by resident and attending surgeons.

RESULTS

Ischemic bowel was seen as a darkened silhouette against the viable fluorescent tissue. Overall, the results show that the use of ultraviolet light and fluorescence in the laparoscopic model is adequate for allowing the identification of ischemic bowel.

CONCLUSIONS

The laparoscopic use of ultraviolet light combined with intravenous fluorescein dye is an effective diagnostic tool for evaluating mesenteric ischemia in pigs.

Use of a fluorescent bile acid to enhance visualization of the biliary tract and bile leaks during laparoscopic surgery in rabbits

BACKGROUND

We set out to determine whether intravenously administered cholylglycylaminofluorescein (CGF), a fluorescent bile acid, would enhance the visualization of the biliary tract and bile leaks in rabbits undergoing laparoscopic cholecystectomy (LC).

METHODS

CGF was infused at doses of 1, 5, and 10 mg/kg b.w. Biliary recovery was determined spectrophotometrically (six rabbits). For LC (seven rabbits), a blue (fluorescein) filter was attached to the light source, and a fluorescein-emission filter was attached to the charge coupled device (CCD) camera. The biliary tract and bile leak (made by incising the gallbladder) was observed under standard and fluorescent illumination.

RESULTS

Apple-green fluorescence appeared in 2 min and persisted for 30-60 min, enhancing visualization of bile duct anatomy as well as the bile leak. Biliary recovery of CGF at 90 min was high (86-96% of the infused dose).

CONCLUSION

In rabbits, CGF is secreted quantitatively in bile, induces biliary fluorescence, and enhances visualization of the bile ducts and bile leaks when viewed with appropriate filters.

Emergency laparoscopy. Technical support for the laparoscopic diagnosis of intestinal ischemia

BACKGROUND

Laparoscopic diagnosis of intestinal ischemia is difficult. Dark-colored bowels are not a reliable indicator for infarction, because there is no correlation between color and oxygenation. The same picture is produced by intraluminal blood or feces. False diagnoses are described.

METHODS

We analyzed various techniques for assessing intestinal oxygenation and perfusion to support laparoscopic diagnosis. In this study laparoscopy was performed on eight pigs. A 10-cm segment of intestine was fixed to the abdominal wall and rendered ischemic. Measurements of the ischemic segment and normal intestine were taken using laser-Doppler, Doppler ultrasound, spectrophotometer, and pulse oximeter. Doppler ultrasound and pulse oximetry were unsuitable in our model, as was laser-Doppler flowmetry.

RESULTS

Only the spectrophotometer proved a highly sensitive means of assessing bowel oxygenation.

CONCLUSIONS

This method provides the desired additional information about intestinal oxygenation, thus helping to interpret the laparoscopic picture of dark bowels.