Therapeutic Value of Gastrografin in Adhesive Small Bowel Obstruction After Unsuccessful Conservative Treatment: A Prospective Randomized Trial

Hok-Kwok Choi, FRCS (Edin); Kin-Wah Chu, FRCS (Edin), FACS; Wai-Lun Law, FRCS (Edin), FACS

Disclosures

Annals of Surgery. 2002;236(1) 

In This Article

Discussion

Adhesive small bowel obstruction can be a complication of any abdominal operation. Studies have reported that appendicectomy and colorectal surgery are the procedures that most commonly caused adhesive obstruction.[2,12,13,14,15] Our results showed that cholecystectomy and gastroduodenal surgery also commonly caused adhesive bowel obstruction.

The management of adhesive obstruction has remained controversial. Most patients received trial conservative treatment in the initial period unless there was suspicion of bowel strangulation. However, the optimal duration of this trial conservative treatment is not clear. There has been no definite answer as to when conservative treatment should be considered unsuccessful and the patient should undergo surgery. Cox et al reported that of patients who were cured by conservative treatment, 88% had obstruction resolved within 48 hours.[16] Assalia et al recommended that surgery should be considered if the obstruction failed to improve after 48 hours of conservative treatment.[8] Sosa and Gardner found that patients without signs of strangulation could be treated nonoperatively for 24 to 48 hours.[17] The reported operative rate for adhesive small bowel obstruction ranged from 27% to 42%.[2,12,13]

This study aimed to evaluate the therapeutic value of Gastrografin for selected patients who had unsuccessful conservative treatment. The ideal design for such a study would require a control arm to continue conservative treatment instead of proceeding to surgery directly. However, to continue conservative treatment for patients who showed no improvement for 48 hours may increase the risk of bowel strangulation. Before we carried out the present study, it was our practice to proceed to surgery if patients showed no clinical and radiologic improvement after receiving conservative treatment for 48 hours. This criterion for proceeding to surgery is generally acceptable according to the literature.[8,16,17] In this study, we randomized these patients to undergo either Gastrografin study or surgical treatment. There was no bowel strangulation in this group of patients with delayed intervention.

The risk factors associated with failure of conservative treatment remain poorly understood. The importance of nasogastric tube output and size of dilated small bowel have seldom been evaluated in the literature. We found that nasogastric tube output was significantly greater in patients who failed to respond to conservative treatment versus those successfully treated with conservative treatment. This could be explained by the difference in the severity of obstruction. An alternative explanation is that the nasogastric tube drainage of patients who responded to conservative treatment decreased with time; therefore, the lower average output. The degree of bowel distention was similar between the two groups, although one might think that patients with grossly distended bowel would be more likely to need surgical treatment. Among the 101 cases treated conservatively for more than 48 hours, only one patient with prolonged obstruction eventually required surgical intervention. Patients who responded to conservative treatment in the first 48 hours had a 99% (100/101) chance of successful nonoperative treatment. Seror et al stated that patients with persistent obstruction for more than 5 days always required surgical intervention.[2] Four patients in our series, however, had bowel obstruction ultimately resolved after conservative treatment for more than 5 days.

Water-soluble contrast medium has been evaluated recently in an attempt to predict the need for surgery in adhesive small bowel obstruction. Studies have also been performed to evaluate its possible therapeutic effect. Gastrografin is the contrast medium most commonly mentioned. It is an ionic, bitter-flavored mixture of sodium diatrizoate, meglumine diatrizoate, and a wetting agent (polysorbate 80). The osmolarity is 1900 mOsm/L, approximately six times that of extracellular fluid. It promotes shifting of fluid into the bowel lumen and increases the pressure gradient across an obstructive site. The bowel content is diluted, and in the presence of the wetting agent, passage of bowel contents through a narrowed lumen is facilitated. Gastrografin also decreases edema of the bowel wall and enhances bowel motility.[6,8,18] Barium has also been used to evaluate adhesive small bowel obstruction; it is not as easily diluted by enteric fluid as Gastrografin and provides a better mucosal image on radiography. However, a barium study can be risky because it may become inspissated and completely obstruct the bowel. Barium may spread into the peritoneal cavity if perforation occurs, a condition that is potentially lethal. Gastrografin is water-soluble and relatively safe even if the obstruction is complicated by perforation. Complications from the use of Gastrografin in small bowel obstruction are rare, although anaphylactoid reactions and lethal aspiration have been described.[19,20,21] Gastrografin may also shorten postoperative ileus and relieve intestinal obstruction caused by impacted Ascaris lumbricoides and bezoar.[8,22,23]

Chen et al studied the predictive role of water-soluble contrast medium in the management of adhesive obstruction.[6] The results of their study showed that patients with contrast observed in the colon within 24 hours were all treated successfully without surgery. Surgery was required in 96% of patients in whom contrast failed to reach the colon within 24 hours. The therapeutic effect of water-soluble contrast in adhesive obstruction is controversial. In a randomized controlled study performed by Assalia et al, Gastrografin significantly prompted the resolution of obstruction, shortened the hospital stay, and reduced the need for surgery to 10% in the treatment group.[9] However, Feigin et al reported no advantage of water-soluble contrast in adhesive small bowel obstruction.[10] The operative rate, time of resolution of obstruction, and hospital stay were similar in the treatment and control groups. Similar results were obtained in Fevang et al's study.[11] The operative rate in the treatment groups was 12% in Feigin et al's study and 35% in Fevang et al's study. There was no complication that could be attributed to the use of the contrast in these studies. Water-soluble contrast medium was given soon after admission in these trials. The method in our study was different: Gastrografin was administered only to patients who failed to respond to conservative treatment. To our knowledge, there has been no similar methodology in other studies. Fourteen of the 19 patients who received Gastrografin had obstruction resolved without surgical intervention. Gastrografin significantly reduced the need of surgery by 74% (14/19). If it was assumed that all 35 patients who showed no response to conservative treatment within 48 hours were given Gastrografin in our series, 9 of them would undergo surgery, and the estimated overall operative rate would be about 9% (13/139). On the other hand, if Gastrografin had not been used, all 35 patients would have undergone surgery, and the overall operative rate would be about 28% (39/139). Concerning the five patients with complete obstruction demonstrated by Gastrografin study, none of these patients had evidence of bowel strangulation at the time of surgery. It was safe to give Gastrografin even after the failure of conservative treatment. Complete resolution of bowel obstruction occurred a mean of 41 hours after administration of Gastrografin. It was usually at least 2 days later that solid food was allowed in our practice. Patients were discharged only when solid food was well tolerated. This could explain why the hospital stay of patients who had received Gastrografin was similar to that of patients who underwent surgery.

We conclude that Gastrografin is safe and reduces the need for surgery when conservative treatment fails.

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