Read Core Topics in General & Emergency Surgery: Companion to Specialist Surgical Practice Online
Authors: Simon Paterson-Brown MBBS MPhil MS FRCS
Core Topics in General & Emergency Surgery: Companion to Specialist Surgical Practice (90 page)
Staple-line leak
These operations have several staple lines to consider: the gastric pouch, the gastro-jejunal anastomosis, the gastric remnant (in a gastric bypass) and the more distal jejuno-jejunostomy. Only the first two of these can be imaged on a contrast swallow. CT may show the others but the receiving surgeon should have a low threshold for returning the patient to theatre for laparoscopy if a leak is suspected. It should be remembered that a tachycardia or elevated C-reactive protein (CRP) may be the only evidence of such a problem in obese patients. If more than 48–72 hours have elapsed since the initial operation, then laparoscopic repair is less likely to be feasible and laparotomy may be required. Surgical treatment should address drainage of sepsis, control of any ongoing leakage and the provision of nutrition (
Box 19.2
).
Box 19.2
Nutritional support in the bariatric patient
It is a mistake to assume that obese patients are well nourished: although their diets may have been high in calories, they have often been deficient in protein, vitamins and other micronutrients. As for any patient with an upper GI anastomotic leak, consideration should be given to commencing enteral feeding or total parenteral nutrition. When re-operating on a bariatric patient for complications, it is sensible to place a feeding gastrostomy or jejunostomy at the same time.
Patients may bleed into the GI tract or into the peritoneal cavity. A bleed into the ‘blind’ gastric remnant after a bypass will only be evident on CT, or by early return to the operating theatre (see
Box 19.3
). Treatment involves establishing drainage of the collection of the haematoma by gastrotomy and controlling the bleeding point, usually by oversewing the staple line. Placement of a transcutaneous gastrostomy tube is wise, not only to decompress the stomach but also to use for later nutritional support if required. Angiographic embolisation of the bleeding point may be an alternative but the surgeon must not allow the inherent delays of such intervention to postpone what might be life-saving re-operative surgery.
Box 19.3
Early recognition of complications is essential
Many of the early complications after gastric bypass and duodenal switch are potentially life threatening. Prompt recognition is important. CT scanning is useful but delay in the diagnosis will worsen a perilous situation so urgent return to theatre is often a better strategy.
Full-thickness injury to the small bowel can easily be incurred as a result of handling with instruments, and perforations may occur ‘off-camera’, out of the laparoscopic field of view. Missed enterotomies may take several days to become apparent, usually presenting with increasing abdominal pain, tachycardia and fever. Enteric fluid may leak out from one or more of the laparoscopic port sites. CT may demonstrate free intraperitoneal fluid and even intraperitoneal gas, but these findings are non-specific. Return to theatre for laparoscopy or laparotomy and drainage/repair is required.
Early postoperative small-bowel obstruction is uncommon after laparoscopic surgery and should not immediately be attributed to a paralytic ileus. Port-site bowel herniation, often of the Richter type, is always a possibility but after operations involving Roux-en-Y reconstruction one should always consider internal herniation, small-bowel volvulus and iatrogenic jejuno-jejunal anastomotic stricture or distortion. Vomiting will be absent if the blind gastroduodenal limb is obstructed and abdominal X-rays may be unreliable, especially in a morbidly obese patient. CT is indicated (
Fig. 19.14
). The treating surgeon should not delay operating to correct an established obstruction.
Figure 19.14
CT scan showing ‘blind’ gastroduodenal biliopancreatic limb obstruction. Note the dilated, fluid-filled stomach and duodenum (large arrows) and the oral contrast in the non-distended alimentary limb (small arrow).
Small-bowel obstruction arising months or years after laparoscopic gastric bypass is a well-recognised problem. The most frequent cause is internal herniation, occurring in up to 7% of cases if the mesenteric defects are not closed.
25
,
26
Hernias typically develop through the mesocolic defect if the retrocolic route is used, the jejunal mesenteric defect at the site of jejuno-jejunostomy, and Petersen's space between the alimentary limb and the transverse colon (see
Fig. 19.15
). For many patients the presentation is insidious, with post-prandial pain and/or bloating. Imaging may not reveal significant small bowel dilatation. Laparoscopy is the investigation and treatment of choice, where chyle within the abdominal cavity is a clue to the diagnosis. The ileocaecal junction is identified first and then the small bowel is carefully ‘walked’ back until the point of internal herniation is seen and reduced. The defect is then closed with non-absorbable material to prevent recurrence.
Figure 19.15
The three common sites for internal hernia after Roux-en-Y reconstruction: the mesocolic defect (green arrow), Petersen's space (blue arrow) and the jejunal mesenteric window (red arrow).
This is a consideration in the medium to long term if a patient develops weight regain. It may also present with dysphagia or pain on eating. It is often associated with stomal ulcers in the gastric pouch, which prove resistant to acid suppression medication, and likely arises following a staple-line leak with abscess formation that discharges into the gastric remnant. The treatment is surgical to divide the fistula and resect some of the distal stomach. This may be achievable laparoscopically.
A recognised complication of gastric resectional surgery, this syndrome comprises post-prandial cramping abdominal pain, nausea, sweating, light-headedness and sleepiness. It reflects hyperinsulinaemic hypoglycaemia, usually precipitated by a high carbohydrate load in the jejunum from rapid gastric emptying,
27
although it is also described after Nissen fundoplication where vagal injury is the likely cause.
28
Mild forms are common and it is rarely severe enough to present as a surgical emergency, but surgeons should nevertheless be aware of it as a cause of post-bypass malaise. Dietary regulation, medication to slow gut motility and/or somatostatin analogues generally provide relief.
A similar spectrum of complications can be expected as might follow a Roux-en-Y bypass, BPD or duodenal switch. However, because of the loop gastro-jejunostomy, bile reflux can be a problem – especially if the efferent limb takes a long time to function. Prolonged nasogastric drainage and nutritional support may be required, with or without the addition of somatostatin analogues or other agents to reduce secretions. If the problem is intractable, conversion to a Roux-en-Y configuration may be necessary.
Nausea and vomiting are almost universal symptoms after balloon insertion but usually subside by the end of the first week. Patients may need intravenous hydration, PPI medication and parenteral anti-emetics over this time. A small minority of patients cannot tolerate oral intake even after several weeks and, in this group, early balloon removal should be offered and will provide instant relief. Although a special kit is produced for balloon removal, it can easily be performed by using a standard endoscopic injection needle (to puncture and empty the balloon) and some strong grasping forceps, or a snare, to remove the deflated balloon.
Abdominal or chest pain is uncommon and should raise the possibility of reflux oesophagitis, gastric ulceration or even gastric/oesophageal perforation. If relief is not obtained with hydration, PPI and anti-emetic medication, then gastroscopy is warranted – though urgent CT is the preferred investigation if perforation is a serious consideration.
There is little information about the long-term outcomes of this new procedure. Epigastric discomfort, attributable either to the transmucosal barbs that fix the collar of the device into the first part of the duodenum, or simply to the foreign body sensation itself, is common and usually settles within a week or two with PPI medication and analgesics. However, several specific complications have been reported.
The device may fail to fix adequately in the duodenal cap and shift out of position. This may cause pain, nausea, bleeding or a degree of gastric outflow obstruction. Abdominal X-ray and/or gastroscopy should diagnose the problem, and endoscopic removal is likely to be required. A special kit is needed and so either the original bariatric surgeon, or alternatively the manufacturers, should be contacted.
This may be minor or catastrophic. Diagnosis and management would be along the lines of any upper GI bleed, although removal of the device is likely to be required if simple endoscopic means do not control the bleeding.
This may occur with a food bolus if the patient does not eat slowly and chew well, but may also arise if the device migrates distally into the small bowel. The wire frame of the collar of the device will be visible on abdominal X-ray but, without some knowledge of the endoscopic procedure done, these appearances may be difficult to interpret. Because of the metal barbs, simply waiting for the device to pass spontaneously is risky and as a result laparotomy is likely to be required.
Whether this is done laparoscopically or endoscopically, the procedure-specific risks include gastric trauma (bleeding or perforation), liver/spleen trauma incurred by traction, direct pressure or injury and perforation of the stomach.
18
As patients will have had their operations many years earlier, only late complications will arise. These include exacerbations of long-standing problems such as blind loop syndrome following a JIB and pouch outlet stenosis after a VBG. Nutritional deficiencies, which may manifest in many ways, are also possible complications (see below).
Gallstones
Dramatic weight loss from any cause promotes gallstone formation owing to mobilisation of cholesterol from peripheral fat stores and changes to the enterohepatic cycle. Patients may present with biliary colic, cholecystitis, pancreatitis or obstructive jaundice and should be managed according to established protocols. Laparoscopic cholecystectomy is generally no more difficult after a bariatric surgical operation than otherwise, but the management of common bile duct stones can be problematic because endoscopic retrograde cholangiopancreatography (ERCP) may be impossible if there has been a previous bypass or duodenal switch/BPD. Intraoperative cholangiography is therefore recommended at the time of cholecystectomy, with concurrent surgical duct exploration as required.
The common nutritional deficiencies seen in the bariatric surgery population concern thiamine, iron, zinc, vitamin D and vitamin B
12
. These may have been present preoperatively, in which case replenishment can be difficult, especially if a malabsorptive-type operation has been done. The clinical features of various deficiency syndromes are well documented but, like the neurological manifestations of thiamine deficiency presenting as Wernicke–Korsakoff's syndrome, may not be readily recognised by general surgeons. If one deficiency is diagnosed then others should be sought. These are of particular importance if re-operative surgery is planned because of the possible detrimental effects that nutritional deficiencies might have on wound healing.
Even the best operations do not work for everyone. While most patients do well in the first few months after surgery, and for many the weight loss is maintained indefinitely as they adopt a new and healthy lifestyle, some degree of late weight regain is very common. This rarely means that the operation has been done incorrectly or failed in some way, although this should be excluded first: bands may become too loose, gastric pouches may stretch, staple lines may disrupt, bypassed bowel may adapt. More usually, however, weight regain reflects a re-emergence of underlying poor eating behaviours – in other words, patients tend to slip back into their old eating habits.
29
Ongoing follow-up with the multidisciplinary bariatric team is important to both prevent and manage postoperative weight regain.
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–
11
Key points
Weight loss operations are becoming more common and complications are increasingly likely to present to the general surgeon on call.
Knowledge of the operation performed will help the receiving surgeon anticipate any problems that might arise.
It is wise to contact the original bariatric surgical team as they may provide useful advice but, as for all emergency admissions, the prime clinical responsibility for the patient rests initially with the receiving surgeon.
Physical examination may be difficult and X-rays may be hard to interpret. Look carefully for clinical and biochemical features of dehydration and sepsis.
Beware the acute band slippage in a gastric band patient. Percutaneous band decompression may provide short-term relief but definitive operative release/removal/resection may be required.
Urgent CT to demonstrate a bleed, leak or obstruction in a patient who is unwell following a gastric bypass or duodenal switch procedure can help to make the diagnosis but immediate return to theatre may be a better strategy.
Incessant vomiting after gastric balloon insertion may respond to inpatient gut rest and anti-emetic medication but instant and permanent relief will be obtained by removal of the balloon.
Tachycardia should never be disregarded as it may be the only clue to an intra-abdominal catastrophe.
Because complications may arise some years after bariatric surgery, patients may no longer be overweight and thus the link to the initial procedure may not be obvious.