Utilidad de la angiografía fluorescente en la cirugía colorrectal / Usefulness of fluorescent angiography in colorectal surgery

RESUMEN Antecedentes: la fístula anastomótica (FA) es una de las complicaciones más severas de la cirugía colo rrectal. Su desarrollo obedece a múltiples factores dependientes del paciente y la técnica operatoria; entre estos últimos podemos mencionar la vascularización de los cabos como uno de los principales. La angiografía fluorescente (AF) permite la evaluación de ese factor en tiempo real durante la cirugía. Objetivo: describir la experiencia en el uso de la AF durante la cirugía colorrectal en un Hospital Uni versitario de la ciudad de Buenos Aires, registrar el cambio de conducta quirúrgica inducido por el uso de la AF y la incidencia de FA. Material y métodos: entre enero de 2016 y junio de 2018 se incluyeron 37 pacientes sometidos a resecciones colónicas programadas y con evaluación de la perfusión con AF. Resultados: la AF pudo realizarse en todos los pacientes con un tiempo operatorio extra de 3 a 9 mi nutos, registrando un cambio de conducta en 4 (10,81%) pacientes. Se registraron 2 (5,41%) fístulas anastomóticas. Conclusiones: la AF con verde de indocianina durante la cirugía colorrectal fue factible, sumó mínima complejidad y tiempo a la operación tradicional, y permitió cambiar la conducta en la sección intestinal en el 11% de los casos, con baja tasa de fístulas anastomóticas.

ABSTRACT Background: Anastomotic leak (AL) is one of the most feared complication of colorectal surgery. Its development is dependent of patient and surgery factors. Of these, bowel perfusion is one of the most important. Fluorescent angiography (FA) allows the identification in real time of the bowel perfusion. Objective: to describe the experience in the use of FA during colorectal surgery in a University Hospital setting in Buenos Aires, to register the change in surgical plan according to the FA findings and record the incidence of AL. Material y methods: Between January 2016 and June 2018, 37 patients with scheduled colorectal resections and FA bowel perfusion assessment were included. Results: Perfusion assessment with FA was possible in all cases with an extra operative time of 3 to 9 minutes, a change in surgical plan was registered in 4 cases (10.81%) and 2 AL were recorded (5.41%). Conclusions: FA during colorectal surgery is feasible, with minimum extra operative time and results in a change in surgical plan in 11% of the cases, and low rate of anastomotic fistula.

Technical description and feasibility of laparoscopic adrenal contouring using fluorescence imaging.

BACKGROUND: Identification of adrenal glands from the surrounding structures during laparoscopic surgery can be challenging especially in obese individuals. This can increase the chances for hemorrhage and conversion to open surgery. We present the first report of fluorescent infrared visualization of the adrenal glands in a large animal model. METHODS: Five adult Yorkshire pigs were utilized for the study, in compliance with the animal study regulations. After an intravenous bolus administration of 3 mL of indocyanine green (ICG), visualization was performed with a xenon/infrared light source and a laparoscope with a charge-coupled filter device. Activation of the device was done with a foot pedal. Images were analyzed using histogram software and the difference of enhancement was statistically analyzed using unpaired two-tailed t test. RESULTS: The right adrenal glands were visualized in all five animals immediately after administering ICG. Fluorescence facilitated demarcation of adrenal gland tissue from surrounding adipose tissue. Peritoneum and fat was visualized in black color. Adrenal enhancement lasted for 4 h in all cases. The mean value for adrenal fluorescence using histogram count was 71.75 pixels, and for adrenal xenon was 168.87 pixels (p = 0.0002; 95 % CI -130.93 to -0.63). The mean value for fat fluorescence using histogram count was 5.54 pixels and fat xenon was 187.15 pixels (p = 0.0001; 95 % CI -199.39 to -163.82). Although there was no significant difference between adrenal and fat enhancement with xenon light (p = 0.24; 95 % CI -15.53 to 52.09), the difference became significant between adrenal and fat fluorescence (p = 0.0001; 95 % CI 48.51-83.9). CONCLUSION: Fluorescence imaging appears to be a feasible and easy method to differentiate adrenal glands from the surrounding tissue in a large animal model. Further studies are necessary to investigate the real application of this method during laparoscopic adrenalectomy in humans.

Novel technique for identification of ureters using sodium fluorescein.

BACKGROUND: The unique property of sodium fluorescein has made it ideal for use in medical applications such as diagnostic ophthalmology and intravenous angiography. It is mainly excreted via the renal system and although extensively used in these diagnostic applications, it has not been widely used to aid in the visualization of the ureters. It is possible to visualize the urinary tract by shining a source of light and studying the fluorescence using a special filter. The goal of our study was to assess the real-time visualization of ureters using intravenous sodium fluorescein under the stimulus of a 530 nm wavelength light. MATERIALS AND METHODS: Nine 250 gm Wister rats were given an intravenous dose of 0.01 ml of sodium fluorescein. A laparotomy was immediately performed following the administration of dye. Anesthesia was performed with an intraperitoneal dose of ketamine-xylazine. The retroperitoneum was exposed and observed under an alternating white xenon and a 530 nm excitation light with an objective to visualize the organs captured within the fluorescence of the compound (sodium fluorescein). RESULTS: Under xenon light, the location of the kidneys and urinary bladder were visualized, but not the ureters. The light was then changed to a 530 nm wavelength mode when the location and orientation of the ureters was visualized along with the peristaltic movements. Fluorescence visualization of the ureters was noted 5-10 min following kidney visualization. In addition, the vascular structures in close proximity to the ureters were also visualized. None of the rats underwent any retroperitoneal dissection, and in one case, partial mobilization of a kidney was undertaken. All rats were euthanized at the completion of the procedure. CONCLUSION: Intravenous administration of sodium fluorescein enables fluorescence visualization of the ureters in a rat model, after activation with a 530 nm light transmitter.

Cost analysis and effectiveness comparing the routine use of intraoperative fluorescent cholangiography with fluoroscopic cholangiogram in patients undergoing laparoscopic cholecystectomy.

BACKGROUND: Despite the standardization of laparoscopic cholecystectomy (LC), the rate of bile duct injury (BDI) has risen from 0.2 to 0.5%. Routine use of intraoperative cholangiography (IOC) has not been widely accepted because of its cost and a lack of evidence concerning its use in preventing BDI. Fluorescent cholangiography (FC), which has recently been advocated as an alternative to IOC, is a novel intraoperative procedure involving infrared visualization of the biliary structures. This study evaluated costs and effectiveness of routinely implemented FC and IOC during LC. MATERIALS AND METHODS: Between February and June 2013, the authors prospectively collected the data of all patients undergoing laparoscopic cholecystectomy. We retrospectively reviewed and compared the use of FC and IOC. Procedure time, procedure cost, and effectiveness of the two methods were analyzed and compared. The surgeons involved in the cases completed a survey on the usefulness of each method. RESULTS: A total of 43 patients (21 males and 22 females) were analyzed during the study period. Mean age was 49.53 ± 14.35 years and mean body mass index was 28.35 ± 8 kg/m(2). Overall mean operative time was 64.95 ± 17.43 min. FC was faster than IOC (0.71 ± 0.26 vs. 7.15 ± 3.76 min; p < 0.0001). FC was successfully performed in 43 of 43 cases (100%) and IOC in 40 of 43 cases (93.02%). FC was less expensive than IOC (US$14.10 ± 4.31 vs. US$778.43 ± 0.40; p < 0.0001). According to the survey, all surgeons found routine use of FC useful. CONCLUSION: In this study, FC was effective in delineating important anatomic structures. It required less time and expense than IOC, and was perceived by the surgeons to be easier to perform, and at least as useful as IOC. Further prospective studies are warranted to evaluate the effectiveness of FC in decreasing BDI.