Core Topics in General & Emergency Surgery: Companion to Specialist Surgical Practice (89 page)
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Authors: Simon Paterson-Brown MBBS MPhil MS FRCS
Jejuno-ileal bypass (JIB)
It is rare to see patients with an intact jejuno-ileal bypass today. This operation involved anastomosing the proximal jejunum to the terminal ileum less than 100 cm from the ileo-caecal valve (
Fig. 19.7
). It gained popularity between the 1950s and1970s before the emergence of the Roux-en-Y gastric bypass operation. The jejuno-ileal bypass resulted in significant protein malabsorption and vitamin/mineral deficiency, the long blind jejunal limb commonly led to bacterial overgrowth, and patients were prone to liver failure as a result of both protein malnutrition and toxaemia from bacterial overgrowth in the blind loop.
9
The majority of patients, if still alive, have had their operations reversed.
Figure 19.7
Diagram of a jejuno-ileal bypass (JIB) procedure. Note the long blind loop of jejunum.
This operation gained popularity in the 1980s and early 1990s but its high failure rate, and the advent ofbetter procedures, has resulted in it being abandoned. Just above the incisura, a short distance in from the lesser curve, the anterior and posterior walls of the stomach were stapled together with a circular stapler. Through the resultant hole made by the stapler, a linear stapler could be applied vertically towards the angle of His. This staple line fixed the anterior and posterior gastric walls together but did not divide the stomach. The outlet of the small gastric pouch thus created was then ‘banded’ with a 360° ring of tape to prevent dilatation (
Fig. 19.8
). The high failure rate resulted from pouch outlet stenosis and/or pouch dilatation (usually caused by overeating), and this was often followed by disruption of the vertical staple line with the consequent loss of restriction to eating.
Figure 19.8
Diagram of the vertical banded gastroplasty (VBG) procedure.
Ileal transposition
This operation is still experimental although it may have an emerging role in patients with diabetes who have a lower body mass index (BMI) than would traditionally be offered weight loss surgery, or in those with no more than truncal obesity (sometimes termed ‘normal-weight obesity’). In essence, a short segment of terminal ileum is excised with preservation of its mesentery, and then re-implanted in an isoperistaltic fashion into the proximal jejunum. This brings endocrine receptors from the hindgut mucosa into the foregut environment, with dramatic effects on the insulin/glucagon axis, pancreatic function and GI tract motility.
21
This endoscopically inserted tube of thin, impervious plastic material has its proximal end secured to the mucosa of the first part of the duodenum with small barbs and then runs distally, effectively lining the duodenum and upper small bowel, preventing ingested food from making contact with the mucosa until the proximal jejunum is reached (
Fig. 19.9
). Its effect on the gut hormone milieu mimics that of the gastric bypass and early clinical results have shown a similar improvement in type II diabetes control, along with modest weight loss. At present it is suggested that such barriers be removed at around 1 year. As yet, however, no long-term follow-up information is available regarding the extent of weight regain or the return of glucose intolerance after the barrier is removed.
Figure 19.9
Diagram of the duodenojejunal scene
Reducing the size of the stomach either endoscopically or laparoscopically has been described where the greater curve of the stomach at the fundus is invaginated to reduce gastric volume.
22
Infolding the gastric wall in this way may also provide stimulation of mural stretch receptors to reduce hunger. Endoscopically this can be performed by firing a series of staples or clips that ‘gather’ the stomach wall from the inside.
23
Outcomes are not yet known, but the same technology has been described previously for plicating the gastro-oesophageal junction for treating reflux where, despite early successes, long-term results have been disappointing.
A number of laparoscopically implantable devices are now undergoing trials. They register the presence of food in the stomach and are designed to mediate satiety by vagal feedback. Lack of outcome data in addition to concerns about battery life and cost are currently a block to their more widespread use.
There are
general
complications such as might follow any abdominal operation, and
specific
complications that relate to the procedure performed.
It should be within the capability of any abdominal surgeon to manage the general complications of bariatric surgery, which include pulmonary atelectasis/pneumonia, intra-abdominal bleeding, anastomotic or staple-line leak with or without abscess formation, deep vein thrombosis (DVT)/pulmonary embolus and superficial wound infections. Patients may be expected to present with malaise, pallor, features of sepsis or obvious wound problems. However, clinical features may be difficult to recognise owing to body habitus. Abdominal distension, tenderness and guarding may be impossible to determine clinically due to the patient's obesity. Pallor is non-specific. Fever and leucocytosis may be absent. Wound collections may be very deep. These complications in a bariatric patient should be actively sought with appropriate investigations. In particular, it is vital for life-threatening complications such as bleeding, sepsis and bowel obstruction to be recognised promptly and treated appropriately. A persistent tachycardia may be the only sign heralding significant complications and should always be taken seriously.
24
It is useful to classify complications as ‘early’, ‘medium’ and ‘late’ because, from the receiving clinician's point of view, the differential diagnosis will differ accordingly (
Table 19.1
). Early complications usually arise within the first few days of surgery but, with ever-advancing laparoscopic surgery and shorter lengths of stay, these may still present to the non-bariatric surgeon after the patient has left the specialist centre.
Table 19.1
General complications following bariatric surgery (similar to those that may arise following any GI operation)
These relate to the procedure performed. Again, they may be grouped into ‘early’, ‘medium’ and ‘late’, although the ‘early’ complications overlap with the general complications mentioned above. Medium-term complications are likely to arise while the patient is still overweight and thus may be difficult to diagnose. Late complications may develop many years later. Patients at this stage may be of normal weight, and therefore a link to their previous bariatric surgery may not be obvious (
Table 19.2
).
Table 19.2
Specific complications of bariatric surgery: early, medium and late
Once the receiving clinician understands the operation that has been performed and the specific complications to look out for, the next step is the interpretation of the presenting clinical features and formulation of a management plan.
Vomiting and/or dysphagia
These are very common and not surprising symptoms, considering that the band works by causing a constriction ring around the upper stomach. Band patients are accustomed to a degree of dysphagia and occasional vomiting, so for them to present for medical attention implies that it is ‘worse than usual’. These symptoms indicate a degree of obstruction at the level of the band and there are three main causes.
Band too tight:
Has the patient had an adjustment recently? Perhaps they have a food bolus obstruction. Once the patient begins to vomit the gastric wall becomes oedematous within the confines of the band and the apparent obstruction becomes worse. The treatment is urgent band decompression using the subcutaneous injection port (see
Box 19.1
and
Fig. 19.10
). Once the patient can drink freely they can be discharged, with arrangement for follow-up by their bariatric specialist team.
Box 19.1
Urgent percutaneous band decompression
The subcutaneous injection port should be palpable beneath the skin on the abdominal wall, usually close to one of the longer laparoscopic scars. Some surgeons place it over the lower sternum. The patient usually knows where it is. Using a strict aseptic technique, the port is steadied between the fingers of one hand while the other holds an empty 10-mL syringe with needle attached. Ideally a non-coring ‘Huber’ or spinal needle is used so as not to damage the port, but in an emergency a conventional 23-gauge hypodermic needle works well (although it may not be long enough). Entering at right angles to the skin, the rubber diaphragm of the port is punctured. The needle hits the metal base-plate with a ‘clunk’ and aspiration can begin. The reservoir is aspirated to dryness; it may contain up to 14 mL. The needle is simply withdrawn when finished and a small dressing applied.
Figure 19.10
Diagram of needle access to the subcutaneous injection port. Strict aseptic technique is important and a non-coring Huber needle should be used.
Acute band ‘slippage’:
This is the term commonly used to describe what is really a process of gastric prolapse upwards through the band. It typically occurs months or years after the original operation and is possibly more common when no gastro-gastric tunnelling sutures are used to secure the band in place. The patient usually presents with vomiting, often in association with being able to eat a sizeable meal, as the food accumulates in the large gastric pouch above the band before eventually being regurgitated. Urgent decompression often provides relief but if not, then an urgent contrast swallow should be ordered. Slippage is often evident on a plain abdominal or chest radiograph, with the band lying at an unusual angle (see
Fig. 19.11
), although a contrast swallow provides more conclusive information. The most serious complication of band slippage is ischaemic necrosis of the prolapsed fundus, secondary to distension and/or occlusion of the blood supply to the proximal stomach as it passes through the band. Failure of the symptoms to resolve with percutaneous band decompression is an indication for urgent surgical intervention.
Figure 19.11
Abdominal X-ray of an acute band slip. The band lies 90° out of alignment (compare with
Fig. 19.1
).
The operation to remove the band is generally by laparoscopy. The tight band must be released. Unclipping it may be difficult, especially laparoscopically, but if possible – and if the stomach is viable – then it may be left in situ for an experienced bariatric surgeon to re-position at a later date. An alternative to unclipping the band is simply to cut it in half, after which it should be removed. Once local adhesions have been divided the band should just slide out. If there is gastric necrosis then laparotomy and some form of gastrectomy will be required along with complete removal of the band, tubing and injection port.
Band erosion:
This is not usually an acute problem but presentation may be precipitated by an aggravation of dysphagia with or without pain and sepsis. Symptoms will not improve after percutaneous band decompression. An urgent contrast swallow may also demonstrate band erosion with leakage of contrast around the band (see
Fig. 19.12
) but the most definitive test for erosion is gastroscopy, where a portion of the white silicone band will be visible from within the lumen.
Figure 19.12
Barium swallow demonstrating band erosion. Note the barium leaking out around the band (arrow). Compare with
Fig. 19.1
.
This is uncommon in band patients (as a result of the band) and so should alert the clinician to a serious problem such as visceral distension from acute slippage (see above), inflammation related to band erosion (see above), peritonitis from gastric necrosis with or without perforation or postoperative haematoma. If the symptoms are of recent onset (hours) and pain is a prominent feature, necrosis and/or perforation should be suspected and urgent imaging is required, followed by laparoscopy with or without laparotomy if necessary. Peritonitis is an unlikely consequence of band erosion but may occur with gastric necrosis (acute band slippage) or perhaps foreign body perforation of the gastric pouch.
This is a common reason for anyone to present to the hospital emergency department and cardiac causes need to be excluded. In patients with a gastric band, the possibility of band slippage, erosion and reflux oesophagitis (secondary to a tight band) needs to be considered.
This is the result of long-standing, excessive restriction and usually follows either a period of excessive band tightness, or chronic malpositioning due to band slippage. It is recognised on a contrast swallow. It usually improves over a period of several weeks following band decompression but may necessitate band removal to prevent recurrence.
Migration:
The subcutaneous injection port may move about within its subcutaneous pocket, depending on how well it has been fixed in position. This makes it difficult to access for percutaneous needle aspiration and if it has flipped over completely, the band will be impossible to decompress.
Leakage:
Repeated attempts to needle the subcutaneous reservoir should be avoided as damage to the rubber diaphragm or perforation/rupture of the tubing can produce a slow leak.
Infection:
The injection port may become infected through breach of sterile technique; this may present as abdominal wall cellulitis or an abscess. An infected port will need to be removed but can be replaced at a later date when the sepsis has completely cleared. Sometimes an infected subcutaneous port may be the first manifestation of band erosion (see above), as the tubing effectively acts as a conduit to convey infected material from the eroded band to the skin surface.
Skin erosion:
The port may also erode through the skin surface (
Fig. 19.13
). While not an emergency, this situation may present to the general surgeon. Again, plans will need to be made for removal, then later replacement, of the injection port.
Figure 19.13
Port erosion through the skin.
Early postoperative reflux/vomiting and dysphagia are common as the narrow and oedematous gastric sleeve tends to empty poorly at first. Some degree of reflux oesophagitis is common. Patients are usually discharged from hospital on proton-pump inhibitor (PPI) medication with instructions to adhere to a fluid diet, gradually thickening their intake over several weeks. However, if the problem is severe or associated with early signs of dehydration, then specific complications should be sought.
Any disruption of the staple line along the narrow sleeve of remaining stomach is likely to cause luminal compression, either from oedema or direct pressure such as from a collection or haematoma. A contrast swallow or computed tomography (CT) should demonstrate this, although both imaging modalities may be falsely negative. Furthermore, some obese patients may be too large for the scanner or X-ray table. If there is reasonable clinical concern of a staple-line leak or bleed, perhaps because of grumbling sepsis or worsening anaemia, laparoscopy should be arranged as this is likely to both confirm the diagnosis and allow repair/control/drainage as necessary.
As the greater omentum is separated from the fundus of the stomach it is possible to take one or more apical splenic vessels, leading to segmental infarction. This will present as left upper quadrant pain with or without some features of sepsis. A contrast CT should demonstrate this. Conservative management is likely to be successful.
The blood supply to the omentum may be compromised if the gastro-epiploic arcade is damaged as it is separated from the stomach. Ischaemic necrosis may be the result, presenting with abdominal pain and features of sepsis. Surgical debridement of the necrotic tissue is likely to be required, either laparoscopically or by open surgery.
This is usually a late complication of a staple-line problem but may be evident within the first week postoperatively if an intense local inflammatory reaction is established, usually following an otherwise undetected leak. After imaging as above, rehydration and possibly nutritional support are all that is required initially. At a later date, once any evidence of active perforation or leak has settled, endoscopic dilatation may help, although this brings its own risk of causing further disruption/perforation. Completion gastrectomy with conversion to a Roux-en-Y bypass may ultimately be required.