Bariatric Surgery: preoperative assessment

: Obesity is associated with increased morbidity and mortality and impaired quality of life. Weight losse is associated with improvement or even cure of cardiovascular risk factors with cardiometabolic benefit. nonsurgical measures for weight loss is rarely successful in the long term. Bariatric surgery has achieved clear success in reversing the abnormal metabolic profile associated with obesity. Pre surgical evaluation is important to rule out any medical or psychological problems that increased the surgical mortality or adversely affect the outcome.

Obesity epidemic is associated with increased burden health-care costs and more utilization of healthcare resources. [5] Weight losses of just 5-10% of initial body weight significantly increased the odds of achieving clinically meaningful changes in glycemic control, blood pressure, HDL cholesterol, and triglycerides at 1 year. [6] In the Diabetes Prevention Program, it became clear that in subjects with a BMI>24 modest weight loss of only 5.6 kg on average reduced the incidence of diabetes by 58%. [7,8] Bariatric surgery has proved to be the most effective mode of treatment of the morbidly obese patients and to date it is the only option resulting in substantial and durable long-term weight loss. [8] A number of factors determine the decision for bariatric surgery based on clinical need, and the potential for long-term outcome benefits against the risks for each patient.
In this assignment the assessment of suitability of a patient for bariatric surgery and pre surgical preparation them is outlined.
The decision to refer patients for bariatric surgery is based on a number of criteria as, obesity degree, patients' age, and absence of any medical or psychological problems that increased the surgical mortality or adversely affect the outcome.
The pre surgical evaluation also involves searching for factors responsible for failure of life style modification and medical treatment in promoting weight loss, these include under lying pathology or drug induced obesity, lack of proper motivation or dietary advices from an expert personal, under lying psychological problem that may precludes the patient from coping with medical treatment and dietary advices.

Degree of obesity
According to AACE/TOS/ASMBS Guidelines suitable candidates for bariatric surgery are those patients with a BMI >40 kg/m 2 without coexisting medical problems and for patients with a BMI >35 kg/m 2 and 1 or more severe obesity related co-morbidities that could be improved by weight loss, including T2D, hypertension, hyperlipidemia, obstructive sleep apnea (OSA), obesity-hypoventilation syndrome (OHS), Pickwickian syndrome (a combination of OSA and OHS), non-alcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH), pseudotumor cerebri, gastroesophageal reflux disease (GERD), asthma, venous stasis disease, severe urinary incontinence, debilitating arthritis, or considerably impaired quality of life.(Recommendation grade A) [9] The evidence for benefit for surgery in these two groups is strong (best evidence level (BEL) 1); based on meta-analysis of randomized controlled trials (MRCT) and randomized controlled trials (RCT).
Studies have demonstrated benefit on mortality, weight loss, diabetes remission; improved beta-cell function and improved pulmonary function.
According to AACE/TOS/ASMBS Guidelines patients with BMI of 30-34.9 kg/m 2 with diabetes or metabolic syndrome may also be offered a bariatric surgery although a welldesigned clinical trials with long follow-up periods to demonstrate safety and benefits in surgical group, compared to medical therapy comparator group is lacking. [9] 2. Age The evidence for effect of age on surgical outcome is conflicting some Surveillance studies have found that older age was a predictor for increased risk of morbidity and mortality after bypass surgery. [10,11] However, more recent studies found that advanced age was not predictor of increased mortality risk after bypass surgery. [12,13] Expert opinion suggests poorer outcomes and more complications in older people.
Some centres have established cut-off levels for age at 65-70 years, while others primarily consider overall health risks and physiological status.
Most guidelines do not recommend the surgery for people aged less than 18 years, as it is more appropriate to address lifestyle issues within the family and social settings. Rule out medical contraindications to bariatric surgery-for example, severe gastrointestinal disease, active cancer, severe heart failure, unstable coronary artery disease, advanced liver disease with portal hypertension, uncontrolled obstructive sleep apnoea with portal hypertension, end-stage lung disease and serious blood or autoimmune disorders and pregnancy.
Crohn's disease may be a relative contraindication to Roux-en-Y gastric bypass and Biliopancreatic diversion, [14,15] and is listed by the manufacturer as a contraindication to the LAP-BAND® system. [16] Laparoscopic surgery may be difficult or impossible in patients with giant ventral hernias, severe intra-abdominal adhesions, large liver, high BMI with central obesity or physiological intolerance of pneumoperitoneum. [16] 2. Look for comorbidities and other factors that may affect the outcome of the surgery Any obesity-related comorbidities should be managed before surgery, when they are identified, and patients may need to be referred to the appropriate specialists (for example, cardiologist, respiratory physician, and endocrinologist).

Psychological evaluation
Obese patients are more likely than the non obese counterparts to have psychopological problems as somatization, social phobia, depression, generalized anxiety disorder, obsessivecompulsive disorder, substance abuse/dependency, binge-eating disorder [16,17] Patients with psychiatric disorders may have a suboptimal outcome after bariatric surgery. [16,17] Pre surgical psychological evaluation is important to help avoid adverse post-operative outcomes Surgery should be undertaken only after there has been a comprehensive evaluation of any psychosocial or other factors that may affect adherence to post-operative care requirements. 10% of Excess body weight loss before surgery is associated with shorter hospitalization and more rapid weight loss. [18] Nonalcoholic fatty liver disease is a risk factor for liver tearing during surgery and preoperative very-low-calorie diet for 6 weeks has been shown to reduce liver volume by 20% and to improve access to the upper stomach during laparoscopic surgery [19,20] , with 80% of the volume change occurring in the first 2 weeks. [19] 6. Respiratory evaluation may include chest radiograph, arterial blood gas, and pulmonary function tests.
Sleep apnea may be diagnosed by sleep study and the patient started on continuous positive airway pressure prior to surgery.
Upper endoscopy may be used if suspicion of gastric pathology exists. If H. pylori infection is present, preoperative therapy is advised. [16] Ultrasound may be used to detect non alcoholic fatty liver, gallstones, allowing the surgeon to decide on concomitant cholecystectomy. In cases of suspected cirrhosis, biopsy may be indicated.

Patient's informed consent to surgery to surgery
The patient should be well informed about the risks and benefits, and is prepared and able to commit to dietary and lifestyle changes.
He must be able to give fully informed consent to bariatric surgery and commit to postoperative care plans.
It should reflect that: [21] a. The patient fully understands the potential benefits, risks and long-term consequences associated with the procedure b. The choice of surgical intervention was made jointly by the patient and the healthcare professionals responsible for treatment, following detailed individualised assessment and discussion of risks and benefits c. The patient is motivated to make necessary dietary and lifestyle changes d. The patient commits to long-term follow-up after surgery.

Perioperative care
The best results are obtained when the surgical team includes an expert anaesthesist support, and highly qualified nurses beside an experienced bariatric surgeon who is able to manage, complication in the intraoperative or the post-operative period.
Availability of a full spectrum of expert consultants (for example, cardiologists, respiratory physicians and psychiatrists) is also necessary.
Management plans should be individualised to ensure optimal results.

Multidisciplinary input
For optimal results of surgery specialist care is provided by a multidisciplinary team that comprises of physicians, surgeons, dieticians and nurses, and should ensure a joint approach to the delivery of care based on the best available evidence. [9,22] Conclusion Obesity is one of the most important public health challenges of the present century; its prevalence is increasing rapidly. Overweight and obesity are associated increased morbidity and mortality and impaired quality of life. Weight losses is associated with improvement or even cure of cardiovascular risk factors with cardiometabolic benefit. The decision to refer patients for bariatric surgery is based on a number of criteria as, obesity degree, in addition to presence of 1 or more of the obesity related morbidities. The pre surgical evaluation also involves searching for factors responsible for failure of life style modification and medical treatment in promoting weight loss, these include under lying pathology or drug induced obesity, lack of proper motivation or dietary advices from an expert personal, under lying psychological problem that may precludes the patient from coping with medical treatment and dietary advices. Pre surgical evaluation is important to rule out any medical or psychological problems that increased the surgical mortality or adversely affect the outcome.