Introduction:

Obesity has recently been called an epidemic.  It is the underlying etiology of a number of disease processes that are the top among causes of mortality in industrialized societies. In the United States, more than 60% of adults are overweight.[i]  Obesity differs greatly from Morbid Obesity. Therapy for obesity and obesity-related medical conditions, currently costs nearly one trillion dollars each decade in the US alone.[ii]  Although both share numerous etiologic factors including genetic, environmental, psychosocial, and economic factors, the accepted treatment options differ. Obesity needs attention and treatment to prevent potential complications, while Morbid Obesity, requires urgent and definitive correction to treat both current complications and highly likely future complications and shortened survival. Whereas medical weight loss may provide beneficial small percentage excessive body weight loss (EBWL) for obese patients, we know that medical weight loss for the morbidly obese has a 95% failure rate and is extremely unlikely to provide sustained results, reduction of morbidity, or improved survival. For this reason, morbidly obese patients are candidates for surgical intervention, which has low morbidity and mortality, and provides a significant and sustained EBWL with reduction of co-morbidity rates and improvement of survival and quality of life. A number of varied procedures exist for the treatment of morbid obesity. The procedures can be performed open or laparoscopically. Located in Virginia, with the second fastest increasing obesity rate (74%) in the nation[iii], our bariatric surgery program has been established to provide bariatric surgical care in a patient-centered manner to the morbidly obese population.  We present here our approach to the care of the morbidly obese patient, discussing the whole perioperative experience with a focus on intra-operative care and nursing considerations.

Patient Selection:

States of over nutrition are classified based on body mass index (BMI). This is calculated by dividing the patient’s weight in kilograms by their height in meters squared. The following chart provides a simplified categorization of states of over nutrition as taken from the American Society of Bariatric Surgery (ASBS) and the National Institute of Health (NIH) and simplified.[iv]

Although BMI can be misleading for very muscular persons, or persons with little to no central or abdominal fat, this problem is limited to those with BMI’s less than 35.  Once the Patient reaches a BMI of greater than 35, measurements such as waist to hip ratio and sagittal abdominal diameter become less important. As such, our criteria remains that of the NIH and ASBS. Patients with prior failed attempts at medical weight loss, and who are currently severely obese (BMI >35) with one or more associated co-morbidities, or who have a BMI of >40 with or without co-morbidities, are considered candidates for surgical treatment.

Choice of Procedure:

            In contrast to the majority of bariatric surgery programs throughout the country, we do not prefer any particular weight loss operation. Our approach is more patient-centered. All operations currently available in the USA and generally accepted in the bariatric surgical community are offered to patients seeking primary treatment for their condition. Of course physiology and underlying dietary and medical issues are considered in making the final decision. Redo patients are even more rigorously evaluated.  Many patients present with a preset decision as to the specific procedure desired and are extensively self-educated at presentation. Others are unsure at the time of presentation and have done little research on options on their own. Regardless, all patients are extensively educated on the history of bariatric surgical operations, their evolution in history due to results and complications, and the currently available procedures in the USA and other procedures or devices that are not available in the USA. Each surgical intervention option is carefully analyzed and pros, cons, risks, and benefits are discussed with attention to short and long term results, weight loss, vitamin and malnutrition risks, and early and late complication rates. Patients are told that the decision is mostly theirs, but that the decision should be based on understanding the etiology of their obesity (source of excess caloric intake if present), the physiology that is best suited to eliminate that source, personal and health goals, risk tolerance, and the ability to tolerate/accept consequences / side effects of the particular procedure(s) contemplated. This process is mediated by the surgeon and generally is in the form of a 1 ½ hour lecture and question-answer session. Immediately following this educational and information-gathering session, the patients attend a support group meeting where they are able to interact with patients who have undergone a number of different operations.  At the support group, the pre-operative patient has an opportunity to meet and discuss their particular concerns with post-op patients of a number of operations. Only after this process is complete are patients actually given an appointment to see the surgeon for physical examination and specific pre-operative testing and scheduling. This allows the patient ample opportunity to contemplate their options and decision and to give truly INFORMED consent. 

Obesity has a number of untoward effects on almost all body systems and has been associated with increased risk for a number of malignancies.

Endocrine/Metabolic:

ü       Hyperlipidemia

ü       Diabetes Mellitus

ü       Gout

ü       Glomerulosclerosis and renal failure

Cardiovascular

ü       Hypertension

ü       Atherosclerotic disease

ü       Venous insufficiency and stasis disease

ü       Varicose veins

ü       Congestive Heart Failure

Pulmonary

ü       Sleep apnea

ü       Obesity hypoventilation syndrome

ü       Asthma

ü       Pulmonary Hypertension

Gastrointestinal

ü       Gall bladder disease

ü       GERD

ü       Fatty Liver

ü       Irritable Bowel Syndrome

ü       Abdominal Wall Hernia

Genitourinary Disease:

ü       Urinary stress incontinence

ü       Dysmenorrhea

ü       Infertility

ü       Polycystic Ovarian Disease

ü       Hirsuitism

Musculoskeletal

ü       Osteoarthritis*

ü       Bone demineralization

ü       Low Back Pain

ü       Carpel Tunnel Syndrome

Neuropsychiatric

ü       Depression

ü       Idiopathic intracranial hypertension

ü       Stroke

Opthalmologic

ü       Glaucoma

ü       Cataracts

Dermatologic:

ü       Panniculitis

ü       Cellulitis

ü       Dermatitis

ü       Necrotizing Infections

Malignancies

ü       Endometrial cancer

ü       Colorectal cancer

ü       Pancreatic cancer

ü       Gallbladder cancer

ü       Uterine cancer

ü       Ovarian cancer

ü       Breast cancer

ü       Prostate cancer

 Non-surgical approaches to weight loss for the morbidly obese are uniformly unsuccessful. No study or intervention other than surgery has provided any meaningful long-term success. This includes dieting, exercise regimens, psychotherapy, or prescription medications.[i] In fact it is currently the consensus that for the morbidly obese, surgery is the only known effective treatment option.

In fact, almost all available surgical interventions provide nearly a 70% EBWL during the first year.[ii] Furthermore, as opposed to failure rates of worse than 95% for non-surgical therapies, there is better than 90% long term success for surgical interventions when using 35% EBWL as the cut-off for success. When using 50% EBWL as the cut-off, the success rate is still better than 70% even for purely restrictive procedures. With bypass procedures and biliopancreatic diversion, success is even greater. With respect to the complications associated with surgery itself, the international registry of bariatric surgeries provides data that reflects an overall operative mortality of 0.17% and a complication rate of only 8.5%.[iii]  Considering the condition and the risks these patients bring with them to the operating room, these represent very low numbers suggesting that surgical intervention is safe, much safer than a lack of intervention. Failure to intervene surgically for these patients undoubtedly results in promulgation of their co-morbidities and eventual morbidity and early mortality.

Anatomic, Physiologic and Patient considerations in selecting the appropriate intervention for patients with morbid obesity:

The most important factor in achieving success in bariatric surgery is patient selection and intervention selection. Most patients who present for evaluation for bariatric surgical procedures are self-referred, determined to achieve change, and willing to make personal life-long sacrifices to achieve their goals. Candidates who are not self-referred, reluctant, uncertain, and attached to certain eating behaviors are to be counseled extensively before proceeding to surgery. Once you have determined that the patient is in the first of the above two categories, or after extensive counseling, therapy as needed, and appropriate time you have succeeded in establishing that the patient belongs to the former category, the next step is education.

Education:

 Anatomic and Historically Known Considerations:

The esophagus is the first passageway into the stomach. History tells us that interventions above or at the level of the esophagus are not effective for the treatment of morbid obesity. For example, wiring the teeth shut is ineffective because the patient’s nutritional source is liquid and shakes. Rapidly, patients consume such high calorie liquids and reach their homeostatic or baseline level of nutritional intake and therefore do not loose weight. The Angelchick prosthesis of the past taught us that obstructive devices on the esophagus were frought with complications such as erosion, and esophageal dilation and are therefore not an option. The EG junction and its physiologic function to relax for food passage and tighten to prevent reflux is important. In patients with significant reflux disease, certain operations should be avoided. The fundus of the stomach has a thin wall and a great propensity to stretch. Prior historical experience tells us to avoid using this portion of the stomach in the formation of a pouch because of this propensity. The body of the stomach produces acid and has muscular digestive function as well for mixing chyme. The lesser curvature of the stomach is the thicker walled portion of the stomach, has lesser propensity to stretch, and is more fixed in position. The pylorus is the outlet of the stomach and is important in regulating the output of the stomach so as to properly limit acid output to the duodenum, control chyme and other fluid output from the stomach, and prevent bile reflux between meals. Denervation of the pylorus results in spasm and obstruction here, and disabling (pyloroplasty or pyloromyotomy) or bypassing the valve results in dumping syndrome because of unregulated emptying of high solute concentration liquids (specifically sweets) into the small bowel. The antrum is the lower 1/3 of the stomach. It is important for two main reasons. First, it harbors G cells that secrete gastrin. This is a paracrine and endocrine hormone that stimulates acid production. This is important when considering the larger pouch of the Scopinaro BPD where the endocrine gastrin effects can increase pouch acid production and increase the rate of ulceration. This is why a distal gastrectomy is recommended with larger pouch procedures. The acid is also important when considering the duodenal switch procedure where preservation of antral acidification helps convert dietary iron to its absorbable oxidized ferric form. Parietal cells in the antrum also produce an intrinsic factor, a protein necessary for B12 absorption in the ileum. The duodenum is important in the secretion of a number of hormones including secretin, cholecystokinin, and enteroglucagon. Leaving the duodenum within the digestive food channel is believed to allow for more normal GI hormonal response to meals which is felt to provide improved physiologic response to meals and improved satisfaction. The bile duct, main pancreatic duct and accessory pancreatic ducts are shown to illustrate the anatomic and surgical hazards associated with performance of the duodenal switch procedure, and to allow for an understanding of its mechanism. The portions of the small bowel are shown with their approximate lengths (unstretched) to allow also for understanding the lengths of intestinal tract used in various parts of the available surgical procedures.

The Simplified Basics of Weight Balance:

The concept of weight balance or caloric equilibrium is based on the concept of basal metabolic rate mandating that each individual has a certain daily caloric need that will result in neither weight gain (anabolism) nor weight loss (catabolism). For most people this is about 1800 calories per day. For some it is lower, for others higher.

Patients who have gained excess body weight, have done so by caloric intake that exceeds their daily caloric need on a daily basis for a sustained period of time. If weight gain is on-going, then this excess intake is on-going.

Weight loss requires that intake (and/or absorption of intake) be reduced below metabolic need on a daily basis for a sustained period of time.  Balance is reached by this process when the patient’s total body size now requires less calories for maintenance, and that need is met by the intake and absorption that the patient is capable of achieving post-operatively. Weight loss therefore stops at this equilibrium.

How then do we reduce the caloric intake of the patient? The best approach is to determine where the EXCESS calories are coming from and eliminate (restrict) that source or prevent that source of excess calories from being absorbed (malabsorption).   In order to target these sources, we attempt to categorize patients’ excess caloric intake sources.

These excesses are categorized as follows:

1)     “Bloating”: over-eating, eating large meals

2)     “Grazing”: constant snacking during the day and between meals or at night.

3)     “Sweeting”: frequent ingestion of high calorie simple sugar containing foods/drinks/shakes

4)     “Choosing”: choosing the wrong foods at each meal (high fat, fried, high carbohydrate, low fiber)

Patients are then asked to classify themselves to determine where their excess calories have come from. If the patient reports that they do not get excess calories currently, then when they were getting excess calories, where did they come from in the past. Most patients can classify themselves into one or two of the above categories, for the most part. Patients who report that they have had stable weight for over one year, are likely to be no longer eating excess calories but rather have truly modified their diets to reach balance. These patients are classified as normal to low metabolizers depending on their reported caloric intake.

The first step in selection is education. The best judge of the patient’s need is the patient. The only limiting factor is the patient’s knowledge base. Once the patient determines their classification, then an effective procedure can be chosen.  This process is accomplished with the patient. Other factors that play into the decision include the patients weight loss goals, short and long-term risk tolerance, and side-effect tolerance.

Flow Chart of Decision making:

Flow Chart of Decision making: