Intraoperative contrast colonography as a method to assess colonic and colorectal anastomosis

ABSTRACT

Anastomotic leakage is a major problem in colorectal surgery, and previous studies have suggested that intraoperative identification of leaks allows repair at the time of surgery. This will decrease the incidence of postoperative leakage [Wheeler and Gilbert 1999]. It is important to prevent leakage after colonic and colorectal anastomoses because of the high incidence of leakage and high mortality associated with it. Some studies had high anastomotic leakage rate from 9.8% to 18% [Karanjia et al., 1994, Benoist et al., 1997, Law et al., 2000, Nesbakken et al., 2001, and Eckmann et al., 2004] while others had lower rate from 2.9% to 7.3% [Vignali et al., 1997, Luna-Perez et al., 1999, Isbister 2001, and Sutton et al., 2004]. Methods to detect leakage are all concerned for postoperative detection. Intraoperative methods to assess colonic anastomosis has been developed and used. These include doppler flowmetry [Boyle et al., 2000] and transanal injection of air [Vignali et al., 1997] or saline [Wheeler and Gilbert 1999]. In this study, we will assess the liability of leakage of colonic and colorectal anastomosis intraoperatively by using a new technique by transanal injection of radiological contrast material at the completion of the anastomosis and taking X-rays to ensure that there is no leakage of the anastomosis. Also, a coloring agent was added for direct visualization of any anastomotic defects. If leakage is present, it has to be secured intraoperatively before closure of the abdomen. This study included 10 patients who were subjected to intraoperative radiological contrast testing after colonic or colorectal anastomosis. The study was conducted in Al Jedani Group of Hospitals in Saudi Arabia between January 2001 and November 2004; There were 7 males and 3 females. Mean age was 49.3 years [range 23-65 years]. The anastomosis performed was either handsewn or stapled anastomosis. We used the non-ionic water-soluble contrast material lohexol [Omnipaque, Amersham Health Inc.] 350 mg1/ml. We used 50 ml lohexol + 50 ml Normal saline 0.9% + 5 ml Methylene blue as a coloring agent. After completion of the anastomosis, its integrity was tested intraoperatively. Transanal injection of the contrast using Foley's catheter No. 22 French. Injection using a manometer to a maximum distending pressure of 25-30 cm. of water. Using the screen to detect leaking anastomosis during injection. Visualization of the coloring agent [Methylene blue] at leaking anastomotic site. Any leaks were repaired and the anastomosis retested until it was free of leakage. Postoperative gastrografin enema was performed at 10th postoperative day. Comparison of data between intraoperative colonography, leaking coloring agent and postoperative study. Indication of resection and anastomosis included colorectal cancer [7 cases], diverticular disease [2 cases] and volvulous with gangrene of sigmoid colon [1 case]. Types and levels of anastomosis included right hemicolectomy [2 cases], left hemicolectomy [1 cases], sigmoidectomy [4 cases], and anterior resection of the rectum [3 cases]. Number of leakage of anastomosis detected by our technique was 3 cases [2 of stapled anastomosis and one of handsewn anastomosis]. These 3 cases were detected by leaking of contrast material under screen and visualization of coloring agent [Methylene blue] at the leaked suture line. There was one case after sigmoidectomy for volvulous with gangrene. The other two cases were after anterior resection for rectal and rectosigmoid carcinoma. There was only one postoperative leakage after anterior resection for cancer rectum. Comparison between in traoperalive colonography and 10th day postoperative study There were 3 cases of anastomotic leakage detected by intraoperative colonography. The defects were repaired intraoperatively. All the 3 cases were not leaking by the 10th postoperative gastrografin enema. Only one case of postoperative leakage was detected by 10th postoperative gastrografin enema which was different from the 3 cases detected and corrected intraoperatively. A total of 2 complications occurred out of 10 patients [20%]. One case of anastomotic leak occurred after low stapling and one case of wound infection. There was no postoperative mortality. A high leak rate has been identified in patients with very low anastomoses. This high leak rate can be avoided by routine use of intraoperative contrast testing of colorectal anastomosis. This is the secret of having a low leak rate. This technique is simple, safe and effective. Although it has the disadvantage of inability to assess the blood supply of the colonic ends, it avoided potential leaks in 3 cases, detected anastomotic defects which can be repaired intraoperatively specially in low anastomosis which can not be directly visualized because of its depth in the pelvis. We recommend routine use of one of modalities for intraoperative assessment of colorectal anastomosis and intraoperative correction of defects detected. We recommend use of intraoperative colonography for larger number of cases to ensure validity of comparison between it and other modalities of intraoperative assessment