Bariatric operations and perioperative care

Selection of procedure

Patient choice

Patients need to have a reasonable knowledge of the concepts of appetite, satiety, and weight-loss maintenance. An understanding of healthy diet, portion sizes, and eating behaviour is mandatory to successful long-term efficacy of bariatric surgery.

Patients should also have an understanding of the main procedures and their pros and cons.

Patients should discuss their own clinical situation with the multidisciplinary team (MDT) and chose a procedure based upon their specific needs and expectations. While the patient should actively choose their procedure, the MDT manages the process. Guidance may be required if the patient chooses an option that the MDT considers clinically inappropriate.

Counselling of procedure risks is especially pertinent to bariatric surgery. Patients must understand the impact of the major complications of each procedure, with emphasis on the relevance to their own life circumstances (e.g. gastric band slippage, gastric sleeve leak).

The importance of regular follow-up to long-term outcomes cannot be overemphasised. Patients must be aware of their obligations to their own health following a bariatric procedure and be fully ‘signed-up’ to comply with long-term review.

Surgical factors influencing selection

Previous surgery may impact on the technical feasibility of bariatric surgery. Previous gastric surgery (e.g. fundoplication) may prevent placement of a gastric band or accurate gastric sleeve formation. Previous intestinal surgery or known small-bowel adhesion disease may preclude any form of intestinal bypass.

Intestinal disease, such as Crohn’s disease or extensive colitis, may render any form of bypass surgery intolerable and unwise. Those patients who have lost significant small intestinal length would also be unwise to consider intestinal bypass for weight loss.

A diagnosis of hiatal hernia does not preclude bariatric surgery. Most bariatric surgeons would repair the hiatus around a suitable oesophagogastric bougie and then proceed with whichever procedure was planned. Anterior repair is preferred for modest defects, while larger hiatal defects are repaired ‘fore and aft’ to prevent oesophageal kinking at the oesophagogastric junction (OGJ).

Gallstones are common among the obese population. Many bariatric surgeons would counsel for a possible cholecystectomy to remove stones and ensure duct clearance before undertaking a bariatric procedure, as gastric band patients with severe cholecystitis may risk infection of the gastric band. Patients with a gastric bypass who suffer small gallstones passing into the common bile duct are faced with a dilemma of access for stone extraction.

Open versus laparoscopic?

The vast majority of modern bariatric surgery is undertaken laparoscopically. Even those that have undergone a prior open abdominal procedure can expect a successful laparoscopic revision procedure.

General preoperative care

Familiarity with the ‘patient pathway’ and preoperative expectation setting

Patients should be carefully counselled regarding their proposed procedure. They should understand the preoperative preparation required, the pre-assessment process and optimisation of comorbidities, and the sequence of events on the day of surgery. This will help allay anxiety and fear regarding the procedure. A careful explanation of the immediate postoperative experience and subsequent early postoperative dietary rehabilitation is useful. Finally, patients should be aware of the expectations for weight loss and dietary tolerance for their procedure.

Patients should also be counselled regarding potential complications and their signs and symptoms. They should also have a contact number in case of emergency, and instruction on where to present and what information to relate to attending doctors.

Nutritional repletion

Despite being obese, many patients can harbour vitamin or mineral deficiency, which must be identified and addressed before surgery is undertaken. Specifically, vitamin B group, vitamins C and D, iron, and folate can be assessed and normalised with dietetic advice and supplementation.

Consent for surgery

The process of patient consent is especially important in bariatric surgery. While many patients will have undergone careful counselling and assessment through the Tier 3–4 process, it cannot be assumed that they understand the personal implications of their surgery and the complications that may arise. It is the operating surgeon’s responsibility to ensure that consent is both informed and appropriate to the individual. Many centres will utilise a detailed procedure-specific consent form that would list both general and procedure-specific risks and complications. Ideally, patients should be given a consent form for their chosen procedure to read and sign at home.

Stabilisation of comorbidities

Patients should undergo a structured assessment by a physician as part of the multidisciplinary management of their perioperative care. Optimisation of any comorbidity is essential to optimal outcomes from surgical intervention.

1.
Obstructive sleep apnoea (OSA): Patients should ideally have been screened for this during their initial referral or Tier 3 work-up. A minimum period of 6 weeks continuous positive airway pressure (CPAP) therapy is recommended before undertaking surgery in a newly diagnosed OSA sufferer. Adequate CPAP therapy is vital to reduce pulmonary hypertension and right heart strain in the preoperative period.
2.
Type 2 diabetes mellitus :

Patients with less-than-optimal control should have a diabetic review before surgery. Blood glucose and HbA1c levels must be optimised to reduce risk in the perioperative period. However, it is accepted that those patients with significant insulin resistance will require bariatric surgery to gain better glycaemic control.

1.
Ischaemic heart disease and hypertension: Optimisation of drug therapy is important to minimise preoperative risk of infarction or stroke. Cardiological advice should be sought in such patients.
2.
Depression: Many patients present for bariatric surgery with depressive illness on medication. Generally, their medication can be continued immediately postoperatively. However, contact with their psychiatrist or general practitioner should be sought to clarify the past psychiatric history and medication requirements.
3.
Non-alcoholic fatty liver disease (NAFLD): The majority of patients presenting for bariatric surgery will have an enlarged fatty liver. This can progress to NAFLD with varying degrees of fibrosis and eventually cirrhosis. Patients with deranged liver function tests should be investigated to exclude gallstones as well as NAFLD. Preoperatively, patients should undergo a very low-calorie diet for at least 2 weeks to effect ‘liver shrinkage’. This is usually achieved by a low-carbohydrate diet, or a milk diet.
4.
Pre-habilitation fitness: Enhancement of patient fitness can be achieved by structured exercise regimes and the encouragement of physical activities in daily life. This has been shown to improve exercise tolerance and recovery following surgery.

Enhanced recovery after bariatric surgery

A variety of schemes have been devised in order to provide a streamlined patient pathway with high-quality perioperative care, designed to achieve a fast-track service. These have many features in common with other enhanced recovery pathways, but require some bariatric-specific points for this patient population.

Day of surgery

Most patients are admitted on the day of surgery. This requires thorough pre-assessment, as well as screening of preoperative blood tests and investigations by an anaesthetist to prevent cancellation. Blood crossmatch is rarely required for elective primary surgery, although many centres will hold a group and save specimens for ‘stapled’ cases or revision surgery.

Venous thromboembolism (VTE) prophylaxis must be prescribed for bariatric patients. NHS hospitals have ‘in house’ protocols for patients of all sizes and these should be applied to all bariatric cases.

Patients should be advised to bring their own CPAP machine to hospital for use postoperatively. This will be optimally adjusted for the individual patient’s use.

Patients are encouraged to walk to the operating theatre if at all possible to avoid issues with handling and bed management. The patient is then asked to self-position on the theatre table and is anaesthetised in-situ.

Requirement for high-dependency unit/HiCare

Patients with severe OSA, complex surgery, or complicated surgery, or the complex comorbid patient will require a greater degree of postoperative monitoring and intervention. These are best managed in a high-dependency unit (HDU)/HiCare setting.

General considerations for surgery

Equipping the service

Staff

Many bariatric surgical units are self-contained services. A minimum of two surgeons, a specialist nurse, a specialist dietician, and a psychologist should make up the surgical team. This allows for availability of appropriate skills and facilitates 24/7 cover for bariatric patients. The availability of a bariatric physician to assist the preoperative management of severe comorbidities would be advantageous.

Furniture

Clearly, patients with high body weight need appropriate furniture. This applies to all points in the patient pathway. Chairs, couches, beds, and theatre tables need to be of an appropriate weight rating for the individual patient. Specifically designed furniture is now available for all shapes and sizes of patients, and it is therefore inappropriate to subject a patient to risk of harm by ‘bodging’ together furniture items to accommodate them. Table lateral extension pieces and footplates are particularly valuable.

Surgical kit

The vast majority of bariatric patients can be managed using standard laparoscopic equipment. Careful port positioning and a willingness to move ports, or use extra ports, gives better access than struggling with ‘difficult’ ports or long instruments.

A choice of laparoscope should be available. Most surgeons would prefer 30-degree angled scopes, but for difficult cases a long 45-degree scope is useful.

Availability of ‘open’ kit

In the rare instance of conversion to open surgery, the availability of suitable mechanised retraction systems is vital to access and efficient operating.

Patient handling and positioning

Patients should be encouraged to move themselves whenever possible. Once anaesthetised, trained personnel should undertake patient handling utilising appropriate aids such as Hover mattresses, slides, and support equipment.

Surgeons differ in their patient position preference. Both supine and split leg configurations have their pros and cons. If a patient is supine on the table, a foot board should be employed to minimise patient slippage when placed steeply head-up to assist access.

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