Revision Bariatric Surgery is Surgical Treatment for Failed or Otherwise Complicated Weight-Loss Operations
There are several reasons why patients may seek out revisional bariatric surgery. For many patients, a single operation to treat obesity is sufficient to produce durable, long-term weight loss without complications. For some patients, however, a weight-loss procedure may yield less-than-optimal results, either through inadequate weight-loss, inadequate resolution of co-morbidities, or by medical complications specifically related to their weight-loss surgery. You may have heard the adage, "if the only tool one has is a hammer, every problem ends up looking like a nail". In the practice of revision bariatric surgery, one needs to make every tool in the toolbox available, and be open to the concept of using new tools as they are developed, as well as understanding the diversity of problems and being able to invent new tools as each situation demands.
Risk and Results
The decision to undergo revisional bariatric surgery is one not to be taken lightly, and, as in any other operation, that decision hinges on weighing the risk against the benefit. Revision bariatric procedures are inherently higher risk than first-time bariatric procedures. They are typically longer procedures, often (but not always) through open incisions, with greater blood loss, and a higher incidence of leak and infection. The higher leak rate is thought to be a result of microscopic changes in blood flow to the stomach, induced by the original surgery. Whereas the results of a revision bariatric procedure are fairly predictable when treating medical complications of weight-loss surgery, the results of revision procedures to further weight-loss are less so. It has been observed that the weight-loss results of revision surgeries do not seem to be as good as if the operation was performed as a first-time procedure. This phenomenon is metabolic in nature; the body appears to undergo metabolic adaptation to the first bariatric operation making subsequent weight-loss more difficult, and patients who are particularly metabolically stubborn are more likely to fail a first-time weight-loss procedure in the first place. Given these factors, revisional bariatric procedures are best approached on a highly individualized basis, tailoring weight-loss surgery to the patient's unique and specific needs.
Revision Bariatric Surgery: Reasons
- Weight Regain/Inadequate Weight Loss
- Inadequate Resolution of Co-morbidities
- Medical Complications
Revision Bariatric Surgery: Specific Revision Considerations
- LapBand
- Roux-N-Y Gastric Bypass
- Vertical Banded Gastroplasty (VBG) and Other "Stomach Stapling" Procedures
- Mini-Gastric Bypass
- Vertical/Sleeve Gastrectomy
- Duodenal Switch
- Metabolic Bone Disease
- Vitamin Deficiencies
Weight Regain/Inadequate Weight Loss
This is the most common reason for patients to consider revisional bariatric surgery. A certain operation may be expected to yield a certain amount of average weight-loss for the "average" patient, but not all patients are "average". A particular patient may not be suited for adapting to the lifestyle required for success for a particular operation; a particular operation may not be suited for the patient's particular metabolism; a particular operation may not maintain its original anatomy over time. All these are reasons why a bariatric operation may fail.
The first consideration is determining whether it is the patient or the operation that has failed. Sometimes patients lack insight into how to make their particular operation work optimally. Getting "back on track" with proper aftercare and support may be all such patients need. Many times, however, a patient's body may be particularly resistant to losing weight after a period of weight regain, which may limit their ability to lose - for a second time - the weight that they had previously lost.
In many instances it is the operation that has failed the patient, whether it be for "mechanical" or for "metabolic" reasons.
Mechanical reasons for failure encompass those instances where the anatomy of the original operation has changed over time. A pouch may stretch out and enlarge; the outlet of a gastric pouch may dilate to a larger diameter; a gastro-gastric fistula may form between a gastric pouch and the bypassed stomach; the absorptive capacity of the intestine may increase beyond that expected; a band may have slowly slipped, resulting in less restriction. In these cases, re-construction of the original surgical anatomy may restore the original conditions that allowed the patient to lose weight in the first place. Re-trimming of a dilated gastric-bypass pouch is one such approach, or a re-trimming of a stretched-out vertical sleeve gastrectomy. Placing a band around a dilated gastric-bypass outlet often makes a suitable remedy for a dilated outlet. Re-stapling broken down staple-lines of gastroplasty procedures has been advocated in the past, but are probably best addressed by conversion to a different bariatric operation, given the high failure rate of gastroplasty operations long-term.
And then there are those cases of metabolic failure, where the operation fails to meet the metabolic needs of the patient.
Success after surgery is often more than a simple matter of watching what one eats; there is a metabolic component to obesity as well, which explains why some people are able to eat massive amounts of food and remain lean, while others are stuck in the rubric of "once on the lips, forever on the hips". "Metabolic failure" is a case of the operation failing the patient. Whereas remedial operations for "mechanical failure" aim to restore the previous anatomy, operations to address "metabolic failure" involve a paradigm shift directed at converting the patient to a more metabolically-active operation. One example of this paradigm-shift thinking would be revising a patient with a stretched out and dysfunctional Gastric Bypass pouch to a Duodenal Switch, as opposed to re-trimming the pouch to restore it to its original size.
For more information on these procedures, see the "Specific Revision Considerations" portion of this section.
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Inadequate Resolution of Co-morbidities
Inadequate resolution of co-morbidities is another reason for consideration for revision/conversion surgery. These considerations are usually related to the causes of metabolic failure, as inadequate resolution of co-morbidities usually parallels inadequate weight-loss, and co-morbidities are intimately linked to metabolism. These cases parallel the approach to metabolic failure cases, and often involve a conversion to a more metabolically active procedure.
For more information on these procedures, see the "Specific Revision Considerations" portion of this section.
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Some patients have medical complications as a result of their weight-loss operations that require revision surgery. Some of these revision procedures parallel the "mechanical" vs. "metabolic" paradigm outlined in the previous section, whereas others require reversal of the original procedure while preserving weight loss. Conditions potentially requiring revision include ulcer, stricture, severe dumping, malnutrition, over-malabsorption, metabolic bone disease, iron deficiency/anemia, vitamin deficiency, vitamin-D deficiency, and thiamine (vitamin B-1) deficiency.
For more information on these procedures, see the "Specific Revision Considerations" portion of this section.
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Revision Bariatric Surgery: Specific Revision Considerations
Patients may require revisional bariatric surgery after LapBand surgery for a variety of reasons. Band slippage may be a slow chronic condition, or an acute surgical emergency. In either event, the band fails to function as it should. Remedial options potentially include band removal, repositioning, or replacement, depending on the circumstances. Removal of the band, of course, leaves the patient with the possibility of weight regain, potentially requiring additional surgery.
Band erosion is another potential complication of LapBand surgery. This is a condition where the band wears a hole into the stomach, rendering the band relatively ineffective. Patients may notice a single episode of vomiting blood as the initial sign of band erosion. The most common presenting symptom is an infection around the port site. This occurs as a result of saliva leaking through the hole in the stomach, tracking along the band tubing, and subsequently infecting the tissues under the skin around the port. Treatment consists of removal of the band. This leaves the patient without a weight-loss operation, making weight regain likely. My recommendation in these instances is to convert the patient to a Vertical/Sleeve Gastrectomy based procedure, such as Vertical/Sleeve Gastrectomy, Duodenal Switch, or VERGITO. These procedures can be performed with a minimal amount of cutting through the area of erosion, which is a weakened part of the stomach made more prone to leak as a result of the erosion.
LapBand failure is another reason for seeking revisional bariatric surgery. LapBand is essentially a restrictive procedure, and not all patients are metabolically tuned to be able to lose the necessary amount of weight with LapBand. Other patients are simply unable to maintain the appropriate eating behaviors that success with LapBand demands, which can result in counterproductive, maladaptive eating patterns, leading to weight regain and failure. Conversion to any other weight-loss procedure is possible, but it is these cases where a paradigm-shift in thinking away from restrictive procedures to more metabolically active procedures is most likely to yield the best results. There is a fair body of evidence that a well-managed LapBand is nearly as good as a Gastric-Bypass over time, as both rely on the maintenance of restrictive eating through similar size pouches long-term. Conversion to a Gastric-Bypass procedure may therefore yield only marginal benefit, while putting the patient at significant risk of leak.
For those patients who still want nothing more than a restrictive procedure, conversion to Vertical/Sleeve Gastrectomy makes an excellent option. Their results will still be limited by the metabolic limitations of their bodies and of the surgery, but there are several ways in which Vertical/Sleeve Gastrectomy may yield better results than LapBand over time. For those patients willing to undergo more involved procedures, proceeding to Duodenal Switch or VERGITO, which build from the platform of Vertical/Sleeve Gastrectomy, make excellent choices. These procedures invoke metabolic mechanisms to maintain weight loss, without relying merely on restriction, and take the patient one step beyond where they were with the original LapBand surgery.
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Patients with Gastric Bypass are candidates for revision surgery for two general reasons: failure (weight gain/inadequate weight loss) and medical complications. Sometimes medical complications of Gastric Bypass may result in failure as well. The causes of failure may be either mechanical or metabolic, with consideration of the patient's eating behaviors as well. Adhering to the principle of "making the best of what you've got", the first step in evaluating a post-Gastric Bypass patient with weight-loss failure is to take a careful inventory of their food intake. Keeping a detailed food diary is the best way to begin to make such an assessment, and patients are often surprised to see what their actual daily intake is. We may have a general idea of what our food intake consists of - what we believe we are eating - only to look back on an accurate food diary and be confronted with the truth. If patients are off track with what they should be doing from a dietary standpoint, getting them back on track is the next step. What happens next is variable: some patients are able to get back on track and back to where they were; some patients get back on track with their eating without success at weight-loss; some patients are never able to resume appropriate eating behaviors, which does not necessarily mean that the patient is "non-compliant". There may be a mechanical reason for patients having to resort to maladaptive eating behaviors, such as what occurs when a patient with an anastomotic stricture falls into the "soft-calorie syndrome" out of necessity, because soft foods are the only foods that can be tolerated without vomiting. We must also realize what it means to be "compliant" with a Gastric-Bypass. What constitutes "appropriate" eating for a Gastric Bypass patient would be a most unusual pattern of eating for the rest of humanity; some people just aren't cut out for that sort of thing, even with the help of a small gastric pouch, and not necessarily due to any character flaw, either.
Reasons for mechanical failure of Gastric-Bypass include gastro-gastric fistula, pouch dilation, and anastomotic dilation. Gastro-gastric fistula is where the stomach pouch grows back and re-connects to the bypassed stomach. This can occur as a consequence of a pouch leak, where the resulting local inflammation from the leak disrupts the staple line of the bypassed stomach where it lies next to the pouch. More often, though, gastro-gastric fistula formation is a result of a less acute, slower process. Regardless the cause, gastro-gastric fistula allows food to pass from the pouch to the bypassed stomach, effectively partially reversing the Gastric-Bypass. Revision surgery for this condition may consist of closure of the fistula, restoring the original surgical Gastric-Bypass anatomy. Conversion to a Vertical/Sleeve Gastrectomy based procedure is an option as well, especially if there are reasons other than mechanical failure to explain the patient's weight gain.
Pouch dilation is a condition where the stomach pouch stretches out and enlarges; anastomotic dilation is where the connection between the stomach pouch and the intestine stretches out. Both conditions result in allowing the patient to eat more than what would be required to remain successful. Re-trimming the pouch to make it small again is one approach to treating pouch dilation. Surgical banding and endoscopic fixation are two approaches to treat an enlarged anastomotic connection. These approaches to pouch and anastomotic dilation are both directed at restoring the anatomy of the Gastric-Bypass procedure back to what it was prior to stretching out. Another approach is to make a paradigm shift and convert to a more metabolically active procedure such as Duodenal Switch. Other Vertical/Sleeve Gastrectomy based procedures are options as well, especially if the patient's Gastric-Bypass is complicated by nutrient malabsorptive issues, such as osteoporosis and anemia.
Conversion from Gastric-Bypass to Duodenal Switch is the most definitive revision procedure for inadequate weight-loss or weight gain after Gastric-Bypass. This approach addresses the issues of metabolic failure and maladaptive eating as causes of failure. This conversion may be done laparoscopically in many cases. A potential concern with this procedure is that of proper stomach function after surgery. The bypassed stomach is now brought back into use, and some patients may have had the nerves to the bypassed stomach cut during their original Gastric-Bypass procedure. This is rarely a problem, as the nerves seem to grow back as the bypassed stomach "wakes up" and resumes working again. Sometimes it may not be safe to re-connect the gastric pouch to the bypassed stomach due to excessive scar tissue. If the patient has acceptable protein tolerance and satisfactory calcium metabolism, conversion to a Scopinaro-type Bilio-Pancreatic Diversion makes a very satisfactory option.
Medical issues complicating Gastric-Bypass include marginal ulcer, stricture, and severe dumping syndrome. These conditions may often be treated conservatively, but when conservative treatment fails, revision surgery is indicated. Treatment for ulcer or stricture may involve resection of the ulcerated/strictured connection between the pouch and the intestine. Another approach is to convert to a Vertical/Sleeve Gastrectomy-based procedure, as stricture and marginal ulcer are conditions that arise as a result of the intrinsic physiology of Gastric-Bypass. This approach is favored for cases of severe dumping as well, as it is the inherent nature of the Gastric-Bypass itself that results in the condition. Rarely, reversal of Gastric-Bypass may be necessary to treat cases of malnutrition, including issues of vitamin and mineral malabsorption. Reversals for nutrient malabsorption may be accompanied by revision to a non-malabsorptive weight-loss procedure, allowing patients to stave off any weight re-gain that may otherwise result from the reversal of their malabsorption.
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Vertical Banded Gastroplasty (VBG) and Other "Stomach Stapling" Procedures
Most patients with VBG and other "stomach stapling" procedures seeking revision surgery do so for two reasons: weight re-gain and maladaptive eating. Although some of these cases can be successfully treated by re-stapling and re-banding, most cases are best treated by conversion to a more definitive procedure. Given the stubbornness of many patients' bodies at losing weight after failure of a weight-loss procedure, conversion to a more metabolically active procedure brings patients out of the difficulty of trying to induce further weight-loss by relying on restriction alone. Revision to Duodenal Switch is one such example, and can often be performed laparoscopically. For patients with previous VBG, removal of the band during revision to Duodenal Switch is not always necessary. Given the variety of stomach-stapling procedures, and the various ways in which their anatomy may change over time, these cases are highly individualized in their surgical approach.
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The issues with revision of Mini-Gastric Bypass procedures are the same as for Roux-n-y Gastric-Bypass. Bile reflux is a potential condition unique to this type of Gastric-Bypass. Although this is an uncommon condition (and a concern more theoretical than actual), revision to Roux-n-y Gastric-Bypass is sufficient to treat this, and is a relatively straightforward conversion, and is done without having to disrupt the original connection between stomach pouch and intestine.
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While highly effective for many, some patients fail to lose adequate weight with Vertical/Sleeve Gastrectomy, and may seek revision surgery in order to induce further weight loss. Sometimes failure is a result of stretching of the stomach, and re-sleeving the stomach may suffice as a revision procedure. For others, adding metabolic and malabsorptive components onto the Vertical/Sleeve Gastrectomy "platform", such as Duodenal Switch and Ileal Transposition, may be indicated. Whereas most revision operations carry a higher risk than first-time bariatric procedures, revision of Vertical/Sleeve Gastrectomy to Duodenal Switch is less risky than performing Duodenal Switch as an all-at-once, first-time operation. Vertical/Sleeve Gastrectomy is one component of a Duodenal Switch procedure, so when converting to a Duodenal Switch procedure, a good portion of the operation has already been done, resulting in a lesser surgery than performing Duodenal Switch in its entirety.
In addition to weight loss, stretching of the stomach may result in other difficulties as well. The stretching of the stomach tube may not be uniform along its entire length, resulting in parts of the stomach tube being more stretched-out than others. This may result in an “Hourglass Stomach”, where the stomach has a large upstream portion separated from an enlarged downstream portion by an area of relative narrowing. This does not necessarily result in increased eating, but may result in uncomfortable, disordered eating. Patients usually experience reflux symptoms and a generalized difficulty eating. Depending on the constellation of the patient’s symptoms and meal volumes, surgical revision may take a couple of forms, but all result in a more direct passage of food from the upstream to downstream stomach.
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Anywhere from 2-5% of Duodenal Switch patients may be candidates for revision surgery. As our understanding of how best to balance the seemingly contradictory demands of weight-loss and malnutrition improves, the likelihood of a Duodenal Switch patient requiring revision surgery can be minimized, but not eliminated entirely. Inadequate weight-loss, excessive weight-loss, and malabsorptive/nutritional deficiencies comprise the most typical reasons for revision of Duodenal Switch.
Excessive weight-loss and malabsorptive/nutritional deficiencies usually go hand-in-hand, and are some of the most straight-forward issues to surgically correct in Duodenal Switch patients. As in many endeavors, timing is everything. The overall malabsorptive effect of Duodenal Switch changes over time, with the intestine becoming more efficient at absorbing protein calories and nutrients. It is important to not revise a patient with malabsorptive complications too early after Duodenal Switch. An earnest attempt at conservative therapy should be instituted prior to revision, to allow time for the natural increase of absorptive capacity of the intestine to manifest itself. If revision is performed too early, patients risk excessive weight re-gain later on, after the intestine has fully adapted. Treatment for malabsorptive complications after Duodenal Switch generally involves adding intestinal length, a process known as elongation. Specific elongations of the common limb using the biliopancreatic limb are possible to obtain specific effects. A fairly common elongation procedure involves an elongation of both the alimentary limb and the common limb, which allows more surface area for protein absorption as well as starch and fat absorption. Increasing the capacity to absorb fat also increases the ability to absorb fat-soluble vitamins such as vitamin-D. Revision procedures to treat protein malnutrition and excessive weight-loss therefore have the added effect of increasing the capacity for fat-soluble vitamin absorption. The simplest procedure to increase both alimentary and common limb length involves a single small intestine connection, known as "entero-enterostomy", known quasi-affectionately by some as a "kissing-X". With elongation procedures patients are generally able to maintain some degree of weight-loss due to the "neuro-endocrine brake" effect, the same mechanism responsible for weight-loss following Ileal Transposition surgery.
Ileal Transposition used as a method of intestinal elongation may be used to treat cases of calcium and iron malabsorption following Duodenal Switch. Unlike a conventional Ileal Transposition, when used in these instances the Ileal Transposition can be performed at the level of the duodenum, without having to re-connect the duodenum, which - after Duodenal Switch - is no small feat. Such "High Duodenal Ileal Transposition" procedures may use only a portion of the alimentary limb to accomplish the transposition, using the remainder of the alimentary limb for a "Parallel Ileal Transposition" at the level of the biliopancreatic limb, which is at that point incorporated back into the flow of food as a result of the High Duodenal Ileal Transposition performed upstream. This approach allows restoration of calcium and iron absorption without having to completely reverse the Duodenal Switch procedure.
Occasionally patients have inadequate weight-loss, or weight regain after a period weight-loss, following Duodenal Switch surgery. Two conceptual approaches to this problem - assuming that a trial at non-surgical weight-loss has failed - are to reduce the stomach size and to shorten the common limb length. Results of these revisions are variable, and, in North America at least, surgically reducing stomach size seems to yield better results than common limb shortening.
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For patients suffering from osteoporosis as a result of weight-loss surgery, there are options for treatment.
With any operation that results in bypassing the duodenum - such as Gastric-Bypass and Duodenal Switch - malabsorption of calcium occurs. The duodenum is the site of maximal absorption of calcium, which is why Gastric-Bypass and Duodenal Switch patients require calcium supplementation. Despite full supplementation, many patients still show signs of malabsorptive metabolic bone disease from calcium malabsorption. Calcium metabolism is monitored post-operatively by measuring blood levels of calcium, vitamin-D, and parathyroid hormone (PTH). It is important to maintain a normal vitamin-D level, as this vitamin is important in maintaining normal calcium levels.
There are a few easily correctable situations that may result in inadequate calcium absorption after these procedures: taking the wrong form of calcium and taking iron supplements that interferes with calcium absorption.
Not all forms of calcium are equally absorbable. Calcium citrate and calcium apatite are known to be easily absorbed. The most common form of calcium supplement - calcium carbonate - is actually poorly absorbed. Many bariatric surgical patients, though, are advised to take this form of calcium for their calcium needs. Although calcium carbonate is quite helpful in preventing kidney stones in bariatric surgical patients, it is a poor choice for preventing osteoporosis. Patients need to be on a form of calcium that they can absorb.
Iron supplements are known to interfere with calcium absorption as well. It is generally recommended that iron pills and calcium pills not be taken within two hours of each other, which can make scheduling one's supplement routine rather difficult. Iron and calcium are both maximally absorbed in the duodenum, which is why metabolic bone disease and anemia often go together in Gastric-Bypass and Duodenal Switch patients. Many patients with iron deficiency will push their iron supplementation to the point that it interferes with their calcium absorption. In their attempt to raise their iron levels to normal, patients worsen their calcium deficiency, resulting in both anemia and osteoporosis. Many patients with iron deficiency require iron infusions when iron pills fail to do the trick. To many patients in this situation, this can be a cause of concern, but it is easier to treat iron deficiency this way than it is to treat calcium deficiency. If the choice is between taking iron pills while putting calcium absorption at risk, or receiving iron infusions while allowing calcium pills to be better absorbed, the clear choice is to take the iron infusions.
Some patients continue to show signs of metabolic bone disease despite high-dose calcium supplementation and healthy vitamin-D levels. For these patients, reversal of their operation may be necessary. Ideally, reversal should be limited to that part of the operation that affects calcium malabsorption, without resulting in excessive weight re-gain. For Gastric-Bypass patients, conversion to Vertical/Sleeve Gastrectomy, with or without Ileal Transposition or Omentectomy, is an effective way to accomplish this. The result is the re-establishment of normal flow through the duodenum while adding the neuro-endocrine brake effect for weight-loss maintenance. For Duodenal Switch patients, a High Duodenal Ileal Transposition will accomplish the same effect without having to totally reverse the patient's operation. Although not the primary goal, revision bariatric surgery for metabolic bone disease also has the effect of improving iron absorption.
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The two classes of vitamins most likely to be deficient in weight-loss surgery patients are the fat-soluble vitamins (A, D, E, K) and certain B-vitamins (B-1/Thiamine, Folate, B-12). Given the effectiveness of oral supplements and vitamin injections, revision surgery to treat these conditions is quite uncommon. Fat soluble vitamin deficiencies are found mainly in Duodenal Switch patients, the most common deficiency being vitamin-D. Elongation of the common limb, as is done for malnutrition/protein deficiency, will usually remedy this problem.
