Imaging Findings in Roux-en-O and Other Misconstructions: Rare but Serious Complications of Roux-en-Y Gastric Bypass Surgery

Transcription

1 Gastrointestinal Imaging Clinical Observations Mitchell et al. Imaging fter Gastric ypass Surgery Gastrointestinal Imaging Clinical Observations Myrosia T. Mitchell 1 runas E. Gasparaitis 1 John C. lverdy 2 Mitchell MT, Gasparaitis E, lverdy JC Keywords: complications, CT, fluoroscopy, gastric bypass surgery, gastrointestinal tract, misconstruction DOI: /JR Received July 12, 2007; accepted after revision ugust 16, Department of Radiology, University of Chicago, 5841 S Maryland ve., MC 2026, Chicago, IL ddress correspondence to M. T. Mitchell (myrosiam@gmail.com). 2 Department of General Surgery, University of Chicago, Chicago, IL. JR 2008; 190: X/08/ merican Roentgen Ray Society Imaging Findings in Roux-en-O and Other Misconstructions: Rare but Serious Complications of Roux-en-Y Gastric ypass Surgery OJECTIVE. The purpose of this study was to present the clinical and imaging findings of Roux-en-O and other misconstructions of Roux-en-Y gastric bypass surgery. The more common complications of Roux-en-Y gastric bypass have been described in the literature. Complications secondary to misconstructions are rare and difficult to diagnose. CONCLUSION. Roux-en-O or other misconstruction should be suspected in patients with chronic bilious vomiting after Roux-en-Y gastric bypass when no mechanical basis for obstruction can be identified. Fluoroscopic motility assessment is often critical in the diagnosis of these misconstructions. T he prevalence of obesity has been steadily increasing since the 1950s [1]. In the management of morbid obesity, surgery has proved better than dieting and lifestyle modifications. ccording to a National Institutes of Health Consensus Conference in 1991, gastric bypass surgery is considered effective and acceptable treatment [2]. For weight reduction, the Roux-en-Y gastric bypass procedure is the most commonly used surgical technique in North merica [3]. First described by Wittgrove et al. [4] in 1994, the operation involves construction of an approximately 20-mL gastric pouch isolated from the distal portion of the stomach. The jejunum is transected cm beyond the ligament of Treitz, and a 100-cm Roux-en-Y limb is made and anastomosed to the gastric pouch (Fig. 1). The more common complications of Roux-en-Y gastric bypass have been described [5, 6]. Complications secondary to misconstruction are rare and difficult to diagnose [7]. Misconstruction occurs when the divided segments of small bowel are misidentified and anastomosed incorrectly. We present our experience with a group of misconstructions we have termed Roux-en-O misconstructions. Materials and Methods This study was conducted with institutional review board approval. retrospective review of our gastric bypass surgical patient database from 2002 to 2004 yielded the cases of four patients who had undergone Roux-en-Y gastric bypass and had a preoperative diagnosis of Roux-en-O misconstruction. In three patients, the diagnosis was suspected clinically because of the presence of chronic bilious vomiting without radiologic evidence of mechanical common limb obstruction. The fourth patient had chronic bilious vomiting with radiologic evidence of complete bowel obstruction. In two cases, the diagnosis of Rouxen-O misconstruction was confirmed at surgery; in the other two cases, other types of misconstruction were identified. Clinical data were reviewed for each patient. Imaging evaluation consisted of fluoroscopic examination, CT, or both. Fluoroscopic examinations were performed with either a remote radiofrequency unit (D-340 Siregraph, Siemens Medical Solutions) or a conventional radiofrequency unit (Sireskop SD, Siemens Medical Solutions). CT was performed with one of two scanners (CTi helical, GE Healthcare; rilliance, Philips Medical Systems). Imaging findings were reviewed by two experienced gastrointestinal attending radiologists (more than 10 years of experience each) to confirm the accuracy of the original imaging interpretations. For fluoroscopic examinations and for CT examinations, a consensus interpretation was made regarding the surgical anatomic features, the loops delineated by enteric contrast material, the presence or absence of bowel dilatation, and any other pertinent pathologic findings. For fluoroscopic examinations, the videotaped record of each study was reviewed in consensus for assessment of bowel motility and evaluation of functional pathologic findings. There were no discrepancies between JR:190, February

2 Mitchell et al. Fig. 1 Schematic shows components of Roux-en-Y gastric bypass procedure. the consensus retrospective interpretations and the original radiology reports of these studies. The clinical data and imaging findings were compared with the surgical findings. Results ll four patients in this study had undergone surgery at hospitals other than ours and had been transferred to our Center for the Surgical Management of Obesity for management of chronic malnutrition and bilious vomiting. The diagnosis of Roux-en-O misconstruction was not suspected before transfer. ll patients needed long periods of nutritional supplementation before undergoing surgery for the misconstruction. During the period, approximately 400 Roux-en-Y gastric bypass operations had been performed at our institution, and none of these operations was complicated by misconstruction. Disconnected Roux-en-O Miscontruction 52-year-old woman had undergone Roux-en-Y gastric bypass 3 months before referral. Her postsurgical course had been complicated by vomiting and by anastomotic dehiscence and leak, which were repaired 2 months after the initial operation. The patient was referred to our facility because of continued bilious vomiting. CT performed with IV and oral contrast media showed the orally administered contrast agent opacifying dilated alimentary and biliary limbs, contrast material reaching the excluded gastric lumen (Fig. 2). The common limb and colon were unopacified and gasless. Surgical exploration revealed a disconnected Rouxen-O misconstruction (Fig. 3). The biliary limb had been incorrectly anastomosed to the proximal gastric pouch, forming a Roux-en-O limb. The distal limb had been reanastomosed to itself and was completely separated from the Roux-en-O limb. The bilious vomiting resolved after surgical revision. Connected Roux-en-O 60-year-old man had undergone Rouxen-Y gastric bypass just over 1 year before referral. He had a prolonged hospital stay because of multiple postoperative complications, including anastomotic leak and septic shock. The patient was referred to our facility for further management of the complications, which included continued vomiting with oral and with gastrojejunal tube feeding, necessitating total parenteral nutrition. We suspected Roux-en-O misconstruction because the findings at multiple endoscopic examinations showed bile in the alimentary Roux limb. Surgical exploration was delayed nearly a year for management of the complications, malnutrition, and newly detected rectal cancer. C Fig year-old woman with disconnected Roux-en-O misconstruction. C, xial reconstruction CT scans show levels of gastric pouch (), descending duodenum (), and distal anastomosis (C). Enteric contrast medium administered orally opacifies markedly dilated gastric pouch (black asterisk, ), alimentary limb (short arrows, and C), and extruded stomach and biliary limb (white asterisks). Common limb, beginning at supposed distal anastomosis (long arrow, C), distal small bowel, and colon (arrowheads and C) are collapsed and gasless. t surgery, biliary limb was found to have been incorrectly anastomosed to gastric pouch, forming Roux-en-O loop that ran from gastric pouch to end blindly in excluded distal stomach. Distal portion of bowel is collapsed and gasless because common limb was completely disconnected from Roux loop. Fig. 3 Schematic shows disconnected Roux-en-O misconstruction. iliary limb is incorrectly anastomosed to gastric pouch. Roux-en-O limb is completely disconnected from Roux-en-Y alimentary limb, resulting in complete mechanical bowel obstruction. limentary limb was oversewn in patient depicted in Figure JR:190, February 2008

3 Imaging fter Gastric ypass Surgery During the management year, the patient underwent numerous imaging studies. Every CT scan showed mild dilatation of the alimentary limb, but the distal anastomosis, common limb, and colon appeared unremarkable (Fig. 4). n initial fluoroscopic examination was performed 1 month after referral (not shown). Contrast material was first administered through a gastric tube in the excluded gastric segment. The scans showed a normal-caliber biliary limb with normal antegrade peristaltic activity. Some angulation of loops was found near the distal anastomosis, a finding compatible with nonobstructing adhesions. Contrast material was then administered orally. The scans showed dilatation of the alimentary limb tapering near the distal anastomosis but without a clear cause. Peristalsis was considerably diminished but was thought to be overall antegrade during that examination. Two subsequent fluoroscopic examinations of the alimentary limb performed 4 and 10 months after referral had similar anatomic findings, but the two studies had different motility findings (Figs. 4 4E). Oral contrast administration showed abnormally diminished peristalsis in the alimentary limb with antegrade passage by gravity only. 15-minute delayed image was obtained for one of the studies. The images showed retrograde passage of contrast material to the gastric pouch. bnormal retrograde peristaltic activity was seen during the real-time examination. Surgical exploration revealed a connected type of Roux-en-O misconstruction (Fig. 5). The biliary limb was incorrectly anastomosed to the proximal gastric pouch. Unlike the findings in the first patient, however, the Roux-en-O limb in this patient communicated with the common limb. The bilious vomiting resolved after surgical revision. Roux Limb Inversion 48-year-old woman had undergone Roux-en-Y gastric bypass approximately 7 months before referral. Chronic vomiting developed after surgery, and because of this complication, the patient underwent four exploratory laparotomies at hospitals other than ours. t the laparotomies, the patient successively underwent cholecystectomy, revision of the Roux-en-Y gastric bypass, jejunojejunostomy revision, and another anastomotic revision. She continued to vomit bile despite ingesting nothing by mouth. She was referred to our facility for further evaluation. C Fig year-old man with connected Roux-en-O misconstruction., Representative axial CT scan through upper abdomen shows nonspecific mild dilatation of upper abdominal bowel loops (thick arrows). Ileum (thin arrow) and colon (arrowheads) are unremarkable. Gastrojejunostomy tube placed in excluded gastric segment is partially evident within transverse duodenum., Patient was given medium-density barium in serial patient-controlled swallows during fluoroscopic observation. Early spot image of gastric pouch (thick arrow) shows patent proximal anastomosis (paired thin arrows) and normal-caliber alimentary limb (arrowheads). Small collection of contrast material lateral to pouch (single thin arrow) is residual contrast agent from earlier anastomotic leak that had healed. C, Fluoroscopic spot image of alimentary limb during initial filling shows normal bowel caliber. Mild indentation of alimentary limb as it goes through transverse mesocolon (arrow) is evident. E Residual enteric contrast material from previous CT examination faintly opacifies colon. D, Fluoroscopic spot image of distal alimentary limb shows mild to moderate dilatation of limb. ntegrade contrast flow is by gravity only with no peristaltic activity observed. Most contrast material has reached distal alimentary limb (arrowheads). E, Fifteen-minute-delayed fluoroscopic spot image of alimentary limb shows retrograde peristalsis (arrows) with return of considerable amount of contrast material into dilated proximal alimentary limb (arrowheads). Fluoroscopy showed contrast material eventually reaching gastric pouch (not shown). D JR:190, February

4 Mitchell et al. Fig. 5 Schematic shows connected Roux-en-O misconstruction. iliary limb is anastomosed to gastric pouch instead of to distal end of Roux-en-Y limb. Proximal end of Roux-en-Y alimentary limb is anastomosed to biliary limb instead of to gastric pouch. Features may look anatomically correct on static images, but peristalsis in Roux limb connected to gastric pouch is reversed (thin arrows), causing functional obstructive symptoms. Initial fluoroscopic examination showed dilatation of the alimentary limb with nondilated distal bowel but no definable cause at the transition point (Fig. 6). radiographic study 2 weeks later showed persistence of contrast material in the alimentary limb (Fig. 6). fter bowel preparation, another fluoroscopic study was performed with mediumdensity barium administered through a gastric tube (Figs. 6C 6F). This examination revealed normal caliber of all small bowel segments and an unremarkable configuration of the distal anastomosis with no evidence of mechanical obstruction. Motility was abnormal, however, with preferential contrast flow into the alimentary limb. Peristalsis within the alimentary limb was predominantly retrograde, contrast material reaching the gastric pouch. preoperative diagnosis of Roux-en-O misconstruction was made. Surgical exploration revealed a limb inversion type of misconstruction (Fig. 7). It was determined that during one of the revisions, a 150-cm Roux limb had been harvested in isolation (both ends cut and separated from remaining small bowel) for use as the alimentary limb. This Roux limb had a 180 twist in its mesentery, so that when it was anastomosed to the stomach proximally and the common limb distally, it was inverted and placed in an antiperistaltic orientation. The entire limb was dilated with no evidence of mechanical obstruction. This antiperistaltic orientation explains the proximal migration of bile over 150 cm to the gastric pouch, a distance too long for random migration. The symptoms resolved after surgical revision of this faux O. Short Roux Limb 51-year-old woman had undergone Rouxen-Y gastric bypass approximately 1 year before referral. She did well for 6 months postoperatively, but then presented with severe upper gastrointestinal bleeding due to an anastomotic ulcer, for which the anastomosis was revised. fter the revision, persistent bilious vomiting and severe weight loss developed, and the patient was referred to our facility. Unenhanced CT performed as a localizing examination for an interventional procedure showed normal-caliber bowel loops. Fluoroscopic examination with contrast material administered through a gastric tube showed normal peristaltic activity of the biliary limb but with preferential flow into the alimentary limb rather than the common limb (Fig. 8). Contrast material ultimately refluxed proximally as far as the gastric pouch. Fluoroscopic examination with an orally administered contrast agent showed a proximal anastomotic stenosis that limited motility assessment of the pouch and the immediately postanastomotic alimentary limb. Surgical exploration revealed an excessively short Roux limb, the alimentary limb measuring only 25 cm from the proximal to the distal anastomosis (Fig. 9). This short length was believed to have allowed considerable bile reflux, causing an anastomotic ulcer. Surgical revision of this faux O resulted in resolution of the bile reflux and ulcers. Discussion Gastric bypass surgery is becoming an increasingly popular option for weight loss by morbidly obese patients. It is more effective than dieting for substantial weight loss and for maintaining weight loss in this patient population [2, 8]. Since its introduction in 1994, Roux-en-Y gastric bypass has become the most commonly used bariatric procedure [3]. nastomotic stenoses and anastomotic leaks are the most common complications diagnosed with imaging [5, 6]. These complications are more likely to affect the proximal anastomosis and are usually easily diagnosed with fluoroscopic examination. Less common complications include abscess, bowel obstruction, hernia, and fistula [7, 9]. bscesses are well depicted with CT. Gastrogastric fistulas can be seen with CT or fluoroscopic examination. Enterocutaneous fistulas are often late complications of leaks and are also usually readily diagnosed with a fluoroscopic examination. Ventral hernias are usually diagnosed with CT, and internal hernias can be diagnosed with fluoroscopic examination or CT. ll of these complications can be identified on the basis of the presence of anatomic distortion and discrete abnormalities visible on static images. Misconstruction occurs when the divided segments of small bowel are misidentified and anastomosed incorrectly. These complications are rare and are difficult to diagnose because the orientation of bowel segments looks completely normal on static images. owel dilatation is sometimes present but is a nonspecific finding that can be caused by a variety of mechanical and functional pathologic conditions. The diagnosis of misconstruction requires careful monitoring of motility during fluoroscopy to identify the abnormal peristaltic activity that characterizes these entities. Roux-en-O misconstruction occurs when the proximal divided jejunum is misidentified as the distal jejunum and is inadvertently anastomosed to the gastric pouch instead of to the distal aspect of the jejunal Roux limb. This misconstruction can occur in the primary operations or during surgical revisions. Early postoperative foregut function may be normal with acceptable tolerance of liquids and pureed foods. Chronic bilious vomiting is a characteristic clinical presentation. lthough bilious vomiting can occur with any obstruction of the common limb, as in the case of the patient with a disconnected Rouxen-O, the presence of this clinical symptom in the absence of common limb obstruction should raise suspicion of misconstruction. ecause of the O-loop configuration of the misconstructed bowel, the normal peristaltic activity of the loop directs the bilious duodenal succus into the alimentary limb toward the gastric pouch and eventually causes bilious vomiting. ttempts by the patient to eat distend the alimentary limb, further stimulating retrograde peristalsis and exacerbating the bilious vomiting. owel dilatation is variable. Fluoroscopic motility assessment should show preferential diversion of biliary limb contents into the alimentary limb and retrograde peristaltic activity of the alimentary limb. If not diagnosed early, Roux-en-O 370 JR:190, February 2008

5 Imaging fter Gastric ypass Surgery D Fig year-old woman with Roux limb inversion., Patient was given medium-density barium in patient-controlled boluses. Spot image from initial fluoroscopic examination shows alimentary limb is dilated (arrowheads) but more distal small bowel is of normal caliber (arrow). Fluoroscopic assessment shows no definable cause at transition point., Radiograph 2 weeks after shows persistence of contrast material in alimentary limb. C, Follow-up fluoroscopic examination was performed after bowel preparation to clear contrast material from alimentary limb. Image obtained after administration of medium-density barium through jejunal tube shows biliary limb of normal caliber. Peristalsis is antegrade within biliary limb. t distal anastomosis, divergent flow of contrast material is evident antegrade into common limb (white asterisk) and retrograde into alimentary limb (black asterisk). Thin arrows indicate direction of peristalsis. D, Spot image obtained minutes after C shows continued abnormal retrograde peristalsis (arrow) diverting contrast material farther up alimentary limb. E, fter acquisition of D, patient was given water-soluble contrast material orally in patient-controlled boluses. Spot image shows dilated gastric pouch (thick arrow) and flaccid and featureless proximal alimentary limb (arrowheads). Peristalsis was initially antegrade (thin arrows). F, Fluoroscopic image shows that with full distention of alimentary limb by contrast material, abrupt reversal of peristalsis (arrow) is evident with return of contrast material to gastric pouch and subsequent marked patient emesis, essentially reproducing symptoms of food intolerance. misconstruction can lead to severe malnutrition because of the patient s inability to keep food down. Roux limb inversion usually occurs when the segments of small bowel are transected at multiple points, resulting in a free segment that can be anastomosed in an inverted antiperistaltic manner [7, 10]. This problem is more likely to occur during revision than in the primary surgical procedure. The antiperistaltic orientation of the limb results in chronic vomiting and intolerance of oral intake; feeding through a gastric tube in the excluded stomach may be tolerated, however. Vomiting may be bilious, possibly because of the proximity of this inverted segment to the distal anastomosis with the biliary limb and the orientation of the distal anastomosis. The diagnosis can be clinically difficult to make. On static images, this inverted alimentary limb is often normal E in caliber and appearance. Diagnosis depends on dynamic fluoroscopic motility assessment. The antiperistaltic limb exhibits luminal dilatation only after an adequate volume challenge of the lumen, at which point dysfunctional retrograde peristalsis is stimulated and is fluoroscopically apparent [7]. Roux-en-Y gastric bypass operations can be performed with a short limb of cm or a long limb of up to 150 cm [11]. In C F JR:190, February

6 Mitchell et al. Fig. 7 Roux limb inversion., Schematic shows normal configuration of free segment Roux-en-Y limb. Orientation of anatomic proximal (P) and distal (D) ends of free segment is maintained, so that peristalsis (arrows) is antegrade., Schematic shows orientation of anatomic proximal (P) and distal (D) ends of free segment are inverted before anastomosis. natomic distal end is anastomosed to gastric pouch, and anatomic proximal end is anastomosed to common limb. s with connected Roux-en-O, the features may look anatomically correct on static images, but peristalsis is reversed (arrows), causing functional obstructive symptoms. Fig. 9 Short Roux limb misconstruction. Schematic shows all segments correctly oriented, but alimentary limb is abnormally short. Shortened length of Roux-en-Y limb allows random bile reflux up to gastric pouch (wavy arrows) despite normal antegrade peristaltic activity of alimentary limb (straight arrow). patients with a body mass index greater than 50, longer limb lengths are associated with greater weight loss [12]. n excessively short limb, as in the patient in whom the limb mea- sured only 25 cm, can allow reflux of biliary contents to the level of the gastric pouch. In our patient, this complication produced bile reflux gastritis and vomiting that mimicked Roux-en-O misconstruction. When gastric bypass patients present with obstructive symptoms, consideration should be given to mechanical obstruction, dysmotility, and misconstruction. Roux-en-O and other Roux-en-Y misconstructions should be suspected in patients with chronic bilious vomiting after Roux-en-Y gastric bypass in whom no mechanical basis for obstruction can be identified. The diagnosis can remain elusive for many months after the initial procedure, resulting in chronic malnutrition. Dynamic fluoroscopic assessment of bowel motility is critical to the radiologic diagnosis of these entities. Imaging findings can be misinterpreted if misconstruction is not considered. cknowledgment We thank Lydia Johns, Department of Surgery, University of Chicago, for the medical illustrations. Fig year-old woman with short Roux limb misconstruction. For upper gastrointestinal examination, medium-density barium was administered through gastric tube in excluded gastric segment. Fluoroscopic image shows distal portion of stomach (asterisk) and biliary limb (arrowheads) are unremarkable. t distal anastomosis, preferential flow of contrast material into alimentary limb (white arrows) is evident with little contrast material passing distally into common limb (black arrow). ntegrade assessment of alimentary limb was limited owing to concomitant proximal anastomotic stenosis (not shown). t surgery, Roux limb measuring only 25 cm was identified. Short length allowed retrograde reflux, resulting in Roux-en-O physiologic characteristics. References 1. National Institutes of Health Obesity Education Initiative. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults: the evidence report. ethesda, MD: National Institutes of Health, National Heart, Lung, and lood Institute, NIH publication no vailable at: guidelines/obesity/ob_gdlns.pdf. ccessed November 20, [No authors listed]. Gastrointestinal surgery for severe obesity: National Institutes of Health Consensus Development Conference statement. m J Clin Nutr 1992; 55[2 suppl]:615s 619S 3. Fisher L, Schauer P. Medical and surgical options in the treatment of severe obesity. m J Surg 2002; 184[suppl]:9S 16S 4. Wittgrove C, Clark GW, Tremblay LJ. Laparoscopic gastric bypass Roux-en-Y: preliminary report of five cases. Obes Surg 1994; 4: Podnos YD, Jimenez JC, Wilson SE, et al. Complications after laparoscopic gastric bypass: a review of 3464 cases. rch Surg 2003; 138: lachar, Federle MP. Gastrointestinal complications of laparoscopic Roux-en-Y gastric bypass surgery in patients who are morbidly obese: findings on radiography and CT. JR 2002; 179: Mitchell MT, Pizzitola VJ, Knuttinen MG, et al. typical complications of gastric bypass surgery. Eur J Radiol 2005; 53: Pories WJ, Swanson MS, MacDonald KG. Who 372 JR:190, February 2008

7 Imaging fter Gastric ypass Surgery would have thought it? n operation proves to be the most effective therapy for adult onset diabetes mellitus. nn Surg 1995; 222: Sandrasegaran K, Rajesh, Lall C, et al. Gastrointestinal complications of bariatric Roux-en-Y gastric bypass surgery. Eur Radiol 2005; 15: FOR YOUR INFORMTION 10. Nelson LG, Sarr MG, Murr MM. Errant and unrecognized antiperistaltic Roux limb construction during Roux-en-Y gastric bypass for clinically significant obesity. Surg Obes Relat Dis 2006; 2: Inabnet W, Quinn T, Gagner M, et al. Laparoscopic Roux-en-Y gastric bypass in patients with MI < 50: a prospective randomized trial comparing short and long limb lengths. Obes Surg 2005; 15: Choban PS, Flancbaum L. The effect of Roux limb lengths on outcome after Roux-en-Y gastric bypass: a prospective, randomized clinical trial. Obes Surg 2002; 12: The merican Roentgen Ray Society now provides instant Web exclusive access to its annual meeting abstracts. The abstracts, featured as a supplement to the merican Journal of Roentgenology, summarize the latest comprehensive and clinically important information presented at RRS s annual meetings. The abstracts can be viewed online by visiting JR:190, February