Radiology of adjustable silicone gastric banding for ... - BIR Publications

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Radiology plays an important role in evaluating complications after gastric restriction surgery. Knowing the variety of findings enables accurate treatment ...
T he British Journal of Radiology, 71 (1998), 717–722

© 1998 The British Institute of Radiology

Radiology of adjustable silicone gastric banding for morbid obesity 1F PRETOLESI, MD, 2G CAMERINI, MD, 1E BONIFACINO, MD, 1F NARDI, MD, 2G MARINARI, MD, 2N SCOPINARO, MD and 1L E DERCHI, MD 1Istituto di Radiologia, Cattedra R, and 2Clinica Chirurgica B, Universita` di Genova, L. go R. Benzi 10, 16132 Genova, Italy Abstract. We reviewed the radiological findings in 45 morbidly obese patients (weight range 80–129 kg; mean 95.7 kg) after gastric restriction surgery with adjustable silicone gastric banding (ASBG) according to the Kuzmak technique. Radiographic studies of the stomach were performed before, and at 4 and 12 months after surgery; symptomatic patients underwent additional studies when needed. Patients were evaluated using both liquid barium and a solid opaque meal to assess post-operative gastric morphology as well as emptying time of the proximal gastric pouch. 27 patients had a normal clinical course. Variation of the calibre of the silicone band under radiographic guidance was required in 12 of these patients, based on dilatation of the proximal pouch, variation of the stomal calibre from operative values, or an emptying time longer than 30 min. All these problems disappeared after the adjustment manoeuvres. 18 patients had complications, of which five had stomal stenosis which could not be managed through simple deflation of the band; two had posterior bending and dilatation of the proximal pouch; four had gastritis and oesophagitis; six had infection of the inflatable reservoir; one had cranial displacement of the band, and two had migration of the band into the stomach. Removal of the gastric band was necessary in 11 cases, and removal of the reservoir alone had to be performed in three additional patients. Radiology plays an important role in evaluating complications after gastric restriction surgery. Knowing the variety of findings enables accurate treatment planning and follow-up of these patients.

Morbid obesity is a chronic pathological condition with associated respiratory, cardiovascular and metabolic complications that both impair quality of life and reduce the lifespan of affected patients [1]. Although diet, combined with behavioural therapy and exercise, is the simplest method of weight control, it often fails to achieve and maintain an acceptable body weight in these patients, and surgery remains the only effective treatment. The surgical interventions employed in the treatment of obesity are aimed at determining a reduction either of intestinal absorption or food intake [1–3]. Gastric restriction procedures cause the patient to experience an early sensation of fullness after ingestion of small quantities of food; the size of meals is then diminished, global food intake decreases, and as a consequence body weight reduces. The vertical banded gastroplasty ( VBG), introduced by both Mason and McLean, and the adjustable silicone gastric banding (ASGB) attributed to Kuzmak are the techniques most widely used [1–5]. In the ASGB [4] the stomach is divided into two pouches by fastening a silicone band around Received 10 October 1997 and in revised form 26 January 1998, accepted 5 March 1998. T he British Journal of Radiology, July 1998

the gastric fundus. At surgery, the gastric fundus is mobilized and a tunnel is created under it by blunt dissection. The silicone band is passed within the tunnel, taking care to avoid both gastric vessels and the vagus nerve. To prevent band displacement, the anterior wall of the distal stomach is sutured over the band to the proximal pouch with three to four silk sutures, and the band is then tightened around the gastric fundus to the desired stomal diameter using special instruments (Figure 1). The band is connected to an inflatable reservoir placed outside the peritoneal cavity, either within the rectus abdominis muscle or under the external thoracic fascia: by means of an injection of a few millilitres of saline into the reservoir, it is possible to tighten or slacken the band and alter the gauge of the stoma between the two portions of the stomach, thus speeding up or slowing down the passage of the alimentary bolus. In terms of weight loss, the results of ASGB are comparable with those obtained using other surgical methods of gastric restriction. Despite its simplicity, the procedure is not free from complications, and radiological techniques have been proven able to identify them and to guide proper patient management [6]. In this study, we describe the radiological examination technique we used and review the radiological 717

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for male patients, or h−100−

h−150 2

for female patients; h is the patient height. The percent reduction of body weight at 12 months was then calculated from: (IOW%−12mOW%)−IOW%

Figure 1. Schematic drawing illustrating the postoperative appearance of the stomach, which is divided into two pouches by the band. The anterior wall of the stomach is sutured over the band to the proximal pouch to prevent band displacement.

appearances of complications encountered in a series of obese patients who had undergone gastric restriction using the technique of Kuzmak [4].

Materials and methods We reviewed the imaging findings obtained in a series of 45 obese patients submitted to ASGB between February 1990 and August 1996 (38 female, 7 male; age range 12–44 years, mean 29 years; weight range 80–129 kg, mean 95.7 kg). Of these patients, 34 had open surgery, while 11 patients were operated on using a laparoscopic technique. A barium study of the upper gastrointestinal tract was performed in all subjects before surgery to exclude the presence of lesions that would constitute contraindications to the operation. Postsurgical clinical and radiological examinations were routinely obtained at 4 and 12 months. Additional examinations were performed when patients reported symptoms suggesting complications. Some patients had follow-up studies at 2 (10 patients), 3 (1 patient), 4 (4 patients) and 6 years (1 patient). At each re-examination patients were weighed and interviewed to assess their food intake. To assess follow-up weight reduction, each patient had his initial overweight percentage (IOW%) calculated using the formula: IOW%=

A

B

RW ×100 −100 IW

in which RW is the real body weight and IW is the ideal body weight. The ideal body weight was calculated according to the formulas: h−100−

718

h−150 4

where 12mOW% is the overweight percentage at 12 months. The radiological study of the stomach initially included evaluation of the diameter of the proximal pouch and the patency and correct positioning of the banding using liquid barium ( barium suspension at 125% w/v). The patients were then given about 50 g of a solid meal consisting of homemade bread containing 20% barium powder, in order to evaluate transit time of solid food between the two portions of the stomach. The examination protocol included anteroposterior and oblique radiographs obtained with the patient standing erect, as well as an anteroposterior view of the stomach with the patient supine and a left oblique anterior projection with the patient in a prone position. When needed, additional views were obtained during fluoroscopy. When faced with specific oesophageal symptoms, an oesophagogram was also carried out.

Results No gastric abnormalities were encountered at radiological studies performed before surgery. In our study population, 27 patients had a normal clinical course and presented no symptoms related to malfunction of the gastric band; they underwent only the examinations programmed in the study protocol. 11 of these patients were operated on laparoscopically and 16 by open surgery. No stoma adjustment was required in 15 cases. In these patients no stoma or pouch changes were seen, according to the values established at the time of surgery (Figures 2 and 3). After ingestion of the solid meal, emptying of the proximal pouch was completed within 15–20 min (Figure 4). Adjustment manoeuvres were necessary in 12 patients. The decision to modify the stoma was based on two criteria. The first was fluoroscopic observation of a too tight or too large diameter, or demonstration of dilatation of the proximal pouch and/or oesophagus, with the liquid barium, as determined by subjective comparison with values established at surgery. The second was a slow passage of solid food through the stoma: persistence of solid food after 30 min was considered as evidence of abnormal stasis. Inflation or deflation of the reservoir was performed under fluoroscopic control. In one patient, the reservoir had migrated cranially and, even after its visualization on a plain film, it could T he British Journal of Radiology, July 1998

Radiology of gastric banding for morbid obesity

Figure 2. Normal post-operative findings on plain abdominal film. The radio-opaque band (arrows), the inflatable port (arrowhead), as well as the small tube connecting them are shown.

not be palpated due to presence of abundant subcutaneous fat. The reservoir was imaged with ultrasound examination of the subcostal region and was punctured under ultrasonic guidance (Figure 5). After the manoeuvre, barium studies showed rapid transit of the contrast medium through the stoma, with little or no stasis in the proximal gastric portion in all 12 patients. Changes to the stoma calibre were also needed in 11/18 patients who had complications (Figure 6). In five of these patients there was stenosis of the stoma which could not be managed through simple deflation of the band. Two other patients had functional stenosis with dilatation due to posterior bending of the proximal pouch over the band. Gastritis and oesophagitis were encountered in four cases; inflammatory reactions around the reservoir with infection, that in one case extended to the band, was seen in six patients (Figure 7). Cranial displacement of the band was observed in one case, while two had migration of

Figure 3. Normal post-operative findings showing good passage through the stoma of the liquid barium.

the band into the stomach. Two patients had multiple complications. Removal of the gastric band was needed in 11 cases, while removal of the reservoir alone had to be performed in three additional patients. Data regarding the kind of complications, the time from surgery, and the necessity for additional operation are summarized in Table 1. With regard to weight control, at the 1 year follow-up 41/45 patients had a significant decrease in weight, with the mean value reduced to 79.3 kg (range 64–104 kg). Only one patient, who did not

Table 1. Complications, time from surgery and necessity for additional surgery in patients having undergone adjustable silicone gastric banding (ASGB) Complications

No. of patients

Time from surgery (months)

Surgical therapy

Stenosis of the stoma Functional stenosis Gastritis and oesophagitis Infection of reservoir

5 2 4 6

7, 7, 24, 24, 68 24, 55 3, 15, 35, 44 3, 3, 3, 10, 18, 44

Cranial displacement Migration of the band

1 2

1 21, 22

Removal of ASGB (5) Removal of ASGB (1) — Removal of reservoir (6) and ASBG (1) — Removal of ASGB

T he British Journal of Radiology, July 1998

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Figure 4. Normal post-operative findings. After evaluation with liquid barium, patients are asked to eat about 50 g of an opaque solid meal. (A) A few minutes after ingestion, most of the meal is within the proximal pouch (arrows) and the distal oesophagus (arrowheads). (B) After 15 min, all opaque bread is within the body of the stomach.

(a)

(b)

Figure 5. (a) Plain film obtained to image a reservoir which could not be appreciated on physical examination (arrows); note presence of food within the proximal pouch. Given the presence of abundant subcutaneous fat, the reservoir could not be palpated even after knowing its location. (b) Ultrasound was needed to locate it and guide its puncture (the arrow is pointing at the surface of the reservoir).

follow the recommended diet, had an increase in body weight.

Discussion ASGB is the least invasive surgical therapy for morbidly obese patients since it does not involve gastric removal, section or stapling and is totally reversible. Furthermore, it is relatively simple to 720

perform, and can be carried out using a laparoscopic approach [7]. Follow-up of the procedure needs close liaison between surgeon and radiologist [6]. Since the silicone band is not sewn directly to the gastric wall, slight displacement can occur during the early post-operative period. Furthermore, although special procedures are employed at surgery to calibrate the diameter of the stoma, a too large or too tight opening may T he British Journal of Radiology, July 1998

Radiology of gastric banding for morbid obesity

Figure 6. Stenosis of the stoma. (A) Dilatation of the proximal gastric pouch, with lack of passage of the liquid meal through the stoma. (B) After deflation of the band, there is normal passage of barium into the distal pouch.

Figure 7. Fistulogram in a patient with cutaneous fistula (arrow) extending both to the inflatable reservoir (open arrow) and to the band (arrowheads).

be fashioned and adjustment manoeuvres under fluoroscopic control have to be performed in many cases. We do not consider this as a malfunction of the ASGB, since the system is actually designed to be modified following implantation according to the needs of each patient. At the first post-surgical examination, at 4 months, barium studies are employed to evaluate both morphology and function of the modified stomach and to guide adjustment of the stoma through inflation or deflation of the reservoir. After identification of patency and measurement of calibre of the stoma with liquid barium, we used opaque bread to mimic the passage of solid food. To the best of our knowledge, no reference data can be found in the literature about transit times through the stoma in ASGB. In our study population, asymptomatic patients T he British Journal of Radiology, July 1998

with good weight reduction had complete passage of 50 g of opaque food in 15–20 min, and we considered as evidence of delayed emptying persistence of solid food in the proximal pouch at 30 min. Although the technique proved effective in achieving weight loss, it resulted in a relatively high number of complications. 18 patients in the present series had complications, and 13 of them underwent a second operation which, in 10 cases, involved removal of the whole system. In the remaining three patients surgery was needed to remove the inflatable reservoir alone. Analysis of the time at which complications occurred in our series of patients shows that, with the exception of functional stenosis and band migration, problems developed at both a short and long time post-operatively. Although it may be difficult to obtain patient compliance with longterm follow-up, this indicates the need for periodic evaluation of these patients, even if asymptomatic and at many years after surgery. Stenosis of the stoma is the most important problem which can occur in these cases, and it usually requires removal of the device [8]. A variety of mechanisms can explain its development. The most important relates to a too tight fastening of the band at the time of surgery, with consequent tissue reaction to the silicone band causing perigastric fibrosis [9], negating the possibility of dilating the stoma by deflation of the reservoir. Furthermore, although silicone is one of the most inert materials used for body implants, it induces a chronic inflammatory response in tissues surrounding the implant itself [10] and can cause secondary stenosis around a well calibrated band. In addition, a stenosis can also be produced if cranial slippage of the anterior gastric wall develops during episodes of vomiting. As a result, the proximal pouch is enlarged but due to discrepancy between the length of its anterior and posterior walls, it bends over the ASGB and causes obstruction of the passage of food. Tissue reaction to silicone [10] can probably be 721

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considered as the most important aetiological factor in the six cases with inflammatory complications involving the reservoir; also minor bacterial contamination from puncture of the reservoir can cause infection in an altered tissue background. To our knowledge, no cases of migration of the band through the gastric wall have been reported in the literature. However, gastric migration is known as a possible complication of the Angelchik prosthesis, which is made of the same material as the ASGB and is placed around the oesophagogastric junction close to the site of the ASGB [11]. We believe that, in both situations, tissue response to silicone is an important aetiological factor in this complication. Pre-operative barium studies did not alter either the surgical approach or the clinical course in any of our patients and, at present, have been omitted from our protocol. Radiology plays an important role in the followup of patients with ASGB for morbid obesity, and has the capability to demonstrate the morphology of the operated stomach and detect post-surgical complications. We have also attempted to use radiological methods to monitor gastric function after ASGB. Although further experience is needed to determine the accuracy and possible role of functional studies in evaluating these patients, the study of transit times between the two gastric sections seems to be a promising technique for assessing the function of the ASGB and improving the care of these patients.

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References 1. Lardinois F, Jacquet P, Belachew M. Gastroplasty as a surgical treatment of obesity. Experience on over 400 operations. Acta Chir Belg 1994;94:75–9. 2. Kuzmak LI. Surgical management of obesity. Hosp Physician 1989;25:41–50. 3. Poulos A, Peat K, Lorman JG, Hatfield DR, Griffen AO Jr. Gastric operation for the morbidly obese. AJR 1981;136:867–70. 4. Kuzmak LI. Silicone gastric banding: a simple and effective operation for morbid obesity. Contemp Surg 1986;28:13–8. 5. MacLean LD, Rhode BM, Forse RA. A gastroplasty that avoids stapling in continuity. Surgery 1993;113:380–8. 6. Pomerri F, Liberati L, Curtolo S, Muzzio PC. Adjustable silicone gastric banding for obesity. Gastrointest Radiol 1992;17:207–10. 7. Morino M, Toppino M, Garrone C, Morino F. Laparoscopic adjustable silicone gastric banding for the treatment of morbid obesity. Br J Surg 1994;81:1168–9. 8. Loving T, Haffner JFW, Kaaresen R, Nygaard K, Stadaas JO. Gastric banding for morbid obesity: five years follow-up. Int J Obes 1993;17:453–457. 9. Kuzmak LI. Gastric banding. In Griffen WO, Printen KJ, editors: Surgical management of obesity. Basel 1987:225–59. 10. Tang L, Eaton JW. Inflammatory response to biomaterials. Am J Clin Pathol 1995;103:466–71. 11. Lilly MP, Slafsky SF, Thompson WR. Intraluminal erosion and migration of the Angelchik antireflux prosthesis. Arch Surg 1984;119:849–53.

T he British Journal of Radiology, July 1998