Selection of Bariatric Procedures

Abstract

Obesity surgery has increased its popularity worldwide in match with the increased obesity rate. Many techniques have shown their beneficial effects on individuals with varying degrees of obesity, including non-obese metabolically ill patients. Current guidelines define selection criteria. In terms of technique the debate is still ongoing. Accurate description of each technique must be done in order to reach a gold standard in the confection of a procedure.

1 Introduction

The socioeconomic circumstances in the Western nations, as well as the profusion of food have drastically changed in the second half of the last century. As a result, the prevalence of morbid obesity has increased rapidly and in some countries obesity has reached an epidemic magnitude. Obesity is a multifactorial entity with aggregation of excessive body fat leading to harm to general health. Basically, morbid obesity is based on an imbalance between calorie uptake and calorie consumption. The causes for this imbalance may differ from patient to patient. For an exact definition/classification and gradation of obesity, the body mass index (BMI) was introduced. BMI is calculated as weight in kilograms divided by the square of height in meters (kg/m².). Based on BMI, obesity is divided into three severity grades: A BMI of 30–35 is considered as grade I obesity, 35–40 as grade II and a BMI >40 as grade III.

The basic treatment of obesity is psychological therapy, diet measures and increasing physical activities.

For patients with a BMI > than 40, the only efficient treatment for weight loss at long term is surgery. The endpoint in evaluating all bariatric surgery is: does the procedure allow the patient to resume physical activities and to maintain a healthy attitude towards food.

Laparoscopic bariatric surgery has been shown to be a safe and effective treatment option causing long-term weight loss in the morbidly obese patient

2 Surgical Indications

The selection criteria for bariatric surgery are clearly defined by EAES guidelines.

General indication: Obesity surgery should be considered in adult patients with a documented BMI greater than or equal to 35 kg/m² and related comorbidity, or a BMI of at least 40 kg/m². All patients must fully understand the proposed procedure and agree with postoperative care. Adults with a BMI between 30 and 35 accompanied by substantial obesity-related comorbidity or after prolonged medical treatment should undergo obesity surgery only in the context of controlled clinical trials.

Based on this precondition the following directives are further formulated by the obesity societies:

• 1. Age of the patients is between 18 and 65 years.

• 2. The patients must have received intensive medical/conservative treatment for weight loss in an obesity treatment center.

• 3. The patients should have undergone conservative therapy for weight reduction under medical supervision with all suitable non-surgical therapies for a minimum period of 12 months.

• 4. Patients with an underlying endocrinological disorder should be excluded.

• 5. Patients should be suitable candidates for general anaesthesia.

• 6. Patients should be aware of the long-term (if necessary lifelong) need for medical follow-up.

• 7. Patients should be willing to change existing eating habits and life style.

National and international professional societies have defined the following as absolute contraindications for a bariatric procedure:

• 1. Abuse of alcohol or drugs

• 2. Concomitant psychiatric comorbidities such as schizophrenia, psychotic condition

• 3. Noncompliance with regard to the necessary lifestyle modifications as well as the prescribed medical aftercare

• 4. Manifest malignancies

• 5. Manifest esophagogastric diseases (e.g. gastric ulcer)

• 6. Limited tolerance to anaesthesia

• 7. Pregnancy

3 Choice of Bariatric Procedure

Available procedures in our department are: adjustable band gastroplasty (AGB), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion with duodenal switch (DS).

There is no consensus on the criteria of choice for one bariatric procedure over another.

The first laparoscopic bariatric procedure was realized in October 1992, and consisted of an AGB. The different procedures experienced successive waves of popularity in Europe: the AGB reached a peak in terms of number of procedures performed in 2004, only to decline rapidly to the benefit of the RYGB that reached a peak in 2007. In turn, the RYGB witnessed a decline from 2010 to the benefit of SG. Conversely, for the DS, the specific indication of the procedure has limited the numbers throughout the years.

There are four criteria to evaluate a bariatric procedure :

• 1. long term efficacy in terms of weight loss : the procedure should in addition allow a healthy attitude towards food

• 2. operative mortality and morbidity (MM): should be less than the MM of the obesity disease.

• 3. late complications including (but not restricted to) GERD, pouch dilation, band erosion, marginal ulcer, stenosis and internal hernia

• 4. quality of life evaluated by subjective and objective parameters including the number and severity of reinterventions

Based on these criteria one can identify the procedures as follows:

• 1. efficacy in terms of weight loss : weight loss varies with the performed procedure, with in decreasing order of efficacy the DS, the RYGB, the SG and the AGB; moreover the latter two procedures may facilitate poor alimentary behavior

• 2. operative MM : procedures involving stapling and/or an anastomosis are likely to carry more morbidity and mortality than AGB. MM figures are, in declining order, linked with DS, RYGB, SG and AGB

• 3. late complications are not amenable to be classified as such because of the inherent complications characteristic for each procedure:

  • For the AGB: band erosion and pouch dilation with GERD

  • For the SG: GERD

  • For the RYGB: anastomotic ulcer and stenosis; dumping, no longer considered a desired side effect, nutritional deficiencies

  • For the DS: protein malnutrition and nutritional deficiencies.

• 4. quality of life : the procedures may be ranked in decreasing order : RYGB, SG, AGB. There are to our knowledge no data available yet for the DS.

The above mentioned criteria will orient the surgeon in his/her choice of procedure for the individual bariatric patient depending on the patient’s characteristics.

Hence, in presence of severe eating disorders such as binge eating (BED), a merely restrictive procedure (AGB, SG) should not be chosen and a malabsorptive operation (DS) preferred.

In case of GERD, SG and AGB should not be chosen because they may worsen the condition, wheres the RYGB is known to improve GERD.

In case of type 2 diabetes (T2DM) (likely the most weight sensitive comorbidity), the most effective procedure should be favoured, i.e. DS and RYGB

In case of super-obesity (BMI >50 kg/m²) the more effective procedure (DS, RYGB) will be chosen.

Decision of final patient procedure selection will additionally depend on the surgeon’s experience, and on the patient’s choice (Fig. 12.1).

Fig. 12.1

Algorithm

4 Preoperative Assessement

Assessment and preparation of the bariatric patient requires a multidisciplinary team approach.

Psychological assessment will allow to rule out binge eating disorder (BED) and to detect anxiety and depression.

Dietary counseling will document past and current eating behavior (grazing, volume eating, sweets eating) and provide the history of weight loss.

Medical history must include previous surgeries and systemic diseases (such as arterial hypertension (AHT), T2DM, sleep apnea), life style and physical activity and present medication that might interfere with the surgery as well as with the weight loss process. Medication that might provide an issue is: anticoagulant drugs, orexogenic drugs such as antidepressants and drugs that cause weight gain such as Metformin and other antidiabetic drugs. Nicotine and alcohol abuse must be ruled out.

Physical examination shall include recording of weight, height (and BMI), neck circumference, blood pressure, examination of existing scars on the abdomen, and heart and lung auscultation

Complete blood work should include: hemoglobin and hematocrit, thyroid hormones, serum cortisol, serum cholesterol and serum triglycerides, iron, Calcium, vitamin D and parathyroid hormone (PTH), liver function tests, Zinc, Magnesium, Selenium, vitamin A, K, E, B1, B6 and B12, fasting plasma Glucose, glycated hemoglobin A1c (HbA1c), Insulin and C peptide (to differentiate T2DM from T1DM).

Cardiovascular and pulmonary assessment is mandatory. This may include in selected patients a cardiac stress test, which should help exclude any contraindication to anesthesia, an echocardiogram to assess left ventricle ejection fraction, pulmonary function tests and arterial blood gas analysis.

An ultrasound examination of the abdomen should be done routinely merely to evaluate liver steatosis and to rule out gall bladder stones. If there are unclear findings, a CT scan or MRI should be performed. All patients should be screened for sleep apnea and treated consequently if needed.

Upper gastrointestinal evaluation should include an esophagogastroduodenoscopy with biopsies of the gastroesophageal junction and stomach to detect esophageal mucosal abnormalities (e.g. reflux esophagitis, Barrett’s mucosa, esophageal/gastric malignancies, the presence of Helicobacter Pylori (HP)) and a barium swallow to detect hiatal hernia.

5 Patient Preparation

A good patient preparation is of the utmost importance to reduce the surgical aggression. Drugs interfering with the surgical procedure (anticoagulants) and substances of abuse (nicotine and alcohol) must be discontinued. Comorbidities should be addressed as needed. T2DM, arterial hypertension should be stabilized by adequate medication; sleep apnea should be treated preoperatively by a continuous positive pressure device (CPAP).

Patients routinely are put on a protein diet for at least 7 days prior to surgery to reduce steatosis

5.1 Different Types of Procedures

5.1.1 Adjustable Band

5.1.1.1 Principle of the Procedure

The satiety center is stimulated by gastric distension and suppresses the feeling of hunger. However, when one eats too fast, the satiety center does not obtain appropriate activation at an optimal time. The feeling of hunger then persists and encourages to continuing eating. With time the stomach adapts and becomes progressively distended which allows the individual to ingest increasingly larger quantities of food without feeling full. The principle of AGB is to reduce the stomach’s volume by dividing it into two parts, similar to an hour glass. With AGB the first compartment has a volume of 25 cc, the equivalent of two tablespoons. The second compartment comprises the rest of the stomach. As soon as one ingests two spoonfuls, the first compartment is filled and one experiences a feeling of fullness. Since it takes a long time for the first compartment to empty because of the narrow outlet, more food can only be ingested after substantial time has elapsed. One must therefore eat at a much slower pace. Because of the slower emptying pace, the satiety center has the time to be stimulated. As the hunger sensation is no longer present, overall food intake is reduced. The outlet size of the first compartment can be adjusted as needed and the pace at which the stomach empties depends on the outlet size, as determined by the status of inflation of the band cuff, depending on the amount of fluid injected into a subcutaneous port which is connected to the cuff.

5.1.1.2 Instruments

• 5 trocars: 3 trocars of 5 mm, 1 trocar of 10 mm, 1 trocar of 15 mm

• 30° optical system

• Veres needle

• band

• 4 atraumatic grasping forceps

• coagulating hook

• suction device

• scissors

• needle-holder

• two stitches of Silk or Prolene 2/0

• two stitches of Ethibond 2/0

5.1.1.3 Technique

5.1.1.3.1 Patient, Team and Trocars Position

The patient is positioned supine with the legs apart and is carefully strapped to the operation table. The arms are placed in abduction. Shoulder supports are placed as well and extreme care is taken to pad the pressure points and articulations with foam cushions. The sequential calf compression devices are placed around the legs and activated. The surgeon (5) stands between the patient’s legs, the cameraman to the patients right (C), the assistant to the patient’s left (A). Abdominal insufflation up to 16 mmHg is obtained with the insertion of a Veres needle at the left upper quadrant, or, alternatively, at the umbilicus. Trocars are placed as follows: a 10 mm trocar (Ti) for the optical system (30° angled scope) just to the left of the midline, 10 cm distal to the xyphoid process; a 15 mm trocar (T2) on the left anterior axillary line 2 cm below the costal margin; a 5 mm trocar (T3) in the left upper quadrant on the mid clavicular line and between the 1″ and 2′d trocar; a 5 mm trocar (T4) in the right upper quadrant on the right mid clavicular line; a 5 mm trocar (T5), used for liver retraction, just distal and to the left of the xyphoid process.

5.1.1.3.2 Dissection of the Phrenogastric Ligament and of the Retrogastric Area

The grasper (T2) pulls the gastric fundus caudally in order to put the phrenogastric ligament under tension. A small window is now created in this ligament using the coagulating hook (T3). Location of this window is usually half way between the upper pole of the spleen and the esophagus just to the left side of the left crus (A). The gastrohepatic ligament is opened widely. The base of the right crus covered by the peritoneal sheet (posterior layer of the gastrohepatic ligament) is identified. The peritoneal sheet is incised (B).

5.1.1.3.3 Retrogastric Tunnel

A grasper (14) is advanced under direct vision from the right crus to the left staying close to the hiatus. The grasper is advanceed until its tip becomes visible in the dissection area of the phrenogastric ligament.

5.1.1.3.4 Introduction and Placement of the Band

An adjustable band with its tubing is introduced into the abdominal cavity through the 15 mm port (12). The band is grasped by the grasping forceps (14) and looped around the stomach at the level of the dissection. The tip of the tubing is introduced in the locking area of the band.

5.1.1.3.5 Calibration and Suture Stabilization of the Band

The anaesthesiologist introduces a balloon tiped orogastric tube inside the stomach, and 25 cc of air is insufflated in the balloon. The tube is pulled back until it fits snugly below the gastro-esophageal junction (A). The surgeon can now be ascertained of the correct positioning of the band, and the band is tightened around the stomach and locked. Four to five stitches (Silk or Prolene 2/0) are placed between the serosa of the stomach just above and below the band to avoid slipping (BC).

5.1.1.3.6 Placement and Injection of the Port

The 15 mm port is removed, and the non-kinking tube is cut to an appropriate length and connected to the injection port (A). The port is buried, convex side up, and stitched (Ethibond 2/0) to the parietal fascia overlying the costal margin to the left (B). The band is left deflated. Alternatively, a minimal amount of methylene blue can be infused into the band through the port, in order to facilitate subsequent fill-up sessions.

6 Postoperative Management

First postoperative day: a gastrograffin swallow is performed and provided good passage is demonstrated and the band is proven to be in a correct position, the patient can be discharged from the hospital.

The adjustment of the band is performed by the radiologist as it requires puncture under fluoroscopic guidance. Fill up sessions start 1 month postoperatively and are repeated as needed. The volume of injected fluid will depend on the pace of clearance of ingested contrast material. The band insufflation will be adjusted based on complications (reflux, food intolerance), on the obtained weight loss and on the radiographical findings

6.1 Gastric Sleeve

6.1.1 Principle of the Procedure

Sleeve gastrectomy is mainly a restrictive procedure of the stomach, aiming at making a gastric tube of 100–150 mL, with the preservation of the antrum. The mechanism of weight loss is to reduce the intake of food, by volume restriction and by reduction of appetite linked to a reduced ghrelin production. Other gastrointestinal hormones may intervene as well.

6.1.2 Instruments

• 5 trocars : 2 trocars of 5 mm, 1 trocar of 10 mm, and 2 trocars of 12 mm

• 30° optical system

• Veres needle

• 4 atraumatic grasping forceps (2 with 5–10 cm marks)

• coagulating hook

• suction device

• scissors

• needle-holder (5 and 10 mm)

• .1 Harmonic scalpel/Ligasure

• 60 mm (45 mm optional) linear stapler (5–6 blue/green/black cartridges)

• one or two stitches of PDS 1

• one stitch of Vicryl 2/0 and of Vicryl1

6.1.3 Technique

6.1.3.1 Patient, Team and Trocars Position

The patient is positioned supine with the legs apart. The patient is carefully strapped to the operation table and the arms are placed in abduction. Shoulder supports are placed and extreme care is taken to pad the pressure points and joints with foam cushions. The sequential calf compression devices are placed around the patient’s legs and are activated. The patient is positioned in slight reversed Trendelenburg position with a 10° tilt. The surgeon (S) stands between the patient’s legs, the cameraman to the patient’s right (C) and the assistant to the patient’s left (A). Abdominal insufflation up to 16 mmHg is obtained with the insertion of a Veres needle at the left upper quadrant, or at the umbilicus. Trocars are placed as follows: a 10 mm trocar (Ti) 20 cm distal to the xyphoid process for the 30° optical system; a 5 mm trocar (T2) on the left anterior axillary line, 5 cm distal to the costal margin; a 12 mm trocar (T3) in the left upper quadrant on the mid clavicular line just between the 1″ and the 2″d trocars; a 12 mm trocar (T4) in the right upper quadrant on the right mid clavicular line; a 5 mm trocar (T5), used for liver retraction, just distal and to the left of the xyphoid process.

6.1.3.1.1 First Technique

After identification of the pylrus, an area some 3–4 cm proximal to it is scored by cautery. The lesser sac is accessed through a window made in the greater omentum, across from the gastric angle, close to the greater curve of the stomach, within the epiploic arch. This window is extended in a caudal direction in order to devascularize the greater curve up to the marking (A). The dissection subsequently proceeds cranially in order to completely dissect the omentum off the greater curve. The dissection thus reaches the base of the left diaphragmatic pillar. The base of the right diaphragmatic pillar should be dissected as well to rule out all potential hiatal hernia. All retrogastric adhesions must be divided (B). A first firing of linear stapler (black or green load) (T4) divides the greater curve in the direction of the crow’s foot. Other firings of linear stapler (black or green load) (13) transect the stomach parallel to the lesser curve, from the antrum up to the angle of His. Before the firing of the stapler, the anesthesiologist advances an orogastric tube of 34 Fr, in order to guide the gastric section (C). A running suture (PDS 1) reinforces the staple line (D). Alternatively, buttress material may be inserted on the staple loads The resected greater curve is extracted through the 12 mm left trocar site (T3).

6.1.3.1.2 Second Technique

After marking the stomach and opening the lesser sac as in the first technique, (A) a window is made in the greater omentum, close to the greater curve, across from the gastric angulus. The greater curvature is devascularized in a caudad direction until the score marks are reached. The stapler is inserted and using black or green load the stomach is transected, hereby guided by an orogastric tube of 34 French introduced by the anesthesiologist, but only up to the level of opening of the lesser sac. Further firings of the linear stapler (black or green load) are kept parallel to the lesser curve. All posterior gastric adhesions are divided. in the direction of the angle of His (C). Before the last firing of stapler (usually green load) (13) the angle of His is freed. In cases where no staple buttressing has been used, the staple line is reinforced by a running suture (PDS 1). The greater omentum is dissected from the now separated greater curve of the stomach, using the coagulating hook or the Harmonic scalpel or Ligasure (0). The resected stomach is then extracted through T3.

6.1.3.2 Leak-Test

The patient is placed in the Trendelenburg position. The operating field is immersed in saline solution. Compressed air is insufflated by the anaesthesiologist into the gastric sleeve. The absence of air bubbles is testimony to the integrity of the sleeve. Importantly, this manoeuvre allows to assess good symmetry of the sleeve as well. The procedure is concluded with the placement of a nasogastric tube and of a drain along the sleeve up to the upper pole of the spleen and the 12 mm left trocar site (T3) is closed with absorbable suture (Vicryl 1).

6.1.3.3 Postoperative Management

On the first postoperative day a methylen blue test is performed and provided there is no evidence of a leak, the nasogastric tube is removed and the patient allowed to drink water. On the third postoperative day the drain is taken out and the patient is discharged.

The patient is restricted to a semi-liquid diet for 1 week, followed by a pureed diet for another 4 weeks. An office visit is scheduled for around that time. When assessment is positive, the patient is advanced to a regular diet. Exercising is encouraged from the fifth postoperative week onwards. Patients are instructed to take either an H2 blocker or proton pump inhibitor, usually for up to 6 months.

6.2 Gastric Bypass

6.2.1 Principle of the Procedure

Biliopancreatic diversion with duodenal switch is primarily a malabsorptive procedure. The biliopancreatic diversion, pioneered in Genoa (Italy), is widely used in Europe and relatively sparingly in the United States. The duodenal switch is an adaptation of the biliopancreatic diversion developed in Canada and America. It consists of a combination of a sleeve gastrectomy and a biliopancreatic diversion. A Roux-en-Y limb is anastomosed to the first part of the duodenum at one end, and to the transeeted bowel some 75–100 cm proximal to the ileocaecal valve at its other end. With the duodenal switch the mechanism of weight loss is double:

• 1. sleeve gastrectomy ensures restriction in the amount of calories taken by mouth

• 2. the functional shortening capacity of the bowel reduces the absorption capacity of the latter since the exchange surface is smaller. Moreover fat can only be digested once the biliary and pancreatic juices are mixed with the food which obviously occurs only quite distally.

6.2.2 Instruments

• 5 trocars: 2 trocars of 5 mm, 1 trocar of 10 mm, and 2 trocars of 12 mm

• 30° optical system

• Veres needle

• 4 atraumatic grasping forceps (2 with 5–10 cm marks)

• coagulating hook

• suction device

• scissors

• needle-holder (5 and 10 mm)

• .1 Harmonic scalpel/Ligasure

• 60 mm (45 mm optional) linear stapler (5–6 blue/green/black cartridges)

• four stitches of PDS 2/0

• one stitch of Silk 2/0

• 2 stitches of Prolene 1

6.2.2.1 Patient Position and Disposition of Trocars

The patient is positioned supine with the legs apart and is carefully strapped to the OR table. The sequential calf compression devices are placed around the patient’s legs and are activated. The surgeon stands between the patient’s legs. The screen is placed above the patient’s head. The patient is placed in steep reversed Trendelenburg. Abdominal insufflation up to 16 mmHg is obtained by the insertion of a Veres needle at the patient’s left upper quadrant or at the umbilicus.

Trocars are placed as follows: a 10 mm trocar for the optical system, (a 30 ° angled scope) immediately to the left of the midline (trocar 1), 10 cm distal to the xyphoid, a 12 mm trocar in the right upper quadrant on the mid clavicular line (trocar 4), a 12 mm trocar in the left upper quadrant on the mid clavicular line at the same level as the optical trocar; a 5 mm trocar used for liver retraction just distal and to the left of the xyphoid (trocar 5) and finally a 5 mm trocar on the left anterior axillary line 5 mm distal to the costal margin (trocar 3).

6.2.2.2 Dissection of the His Angle

The liver is retracted with a 5 mm rod retractor inserted through the subxyphoid port. The root of the left diaphragmatic crus is exposed by caudad traction on the stomach fundus by the assistant to the patient’s left, and the phrenogastric ligament is incised at the level of the angle of His with a coagulating hook (3) until visualization of the left diaphragmatic crus is obtained.

6.2.2.3 Dissection of the Lesser Curvature

Dissection is then initiated at the lesser curvature 5–6 cm under the esogastric junction. The third vessel (counting from proximal) is identified at this lesser curvature and a plane developed between Latarjet’s pedicle and the serosa of the stomach. By continuing the dissection posteriorly the lesser sac is entered.

6.2.2.4 Gastric Pouch Manufacturing

The stomach is transected horizontally at that level by one firing of the linear stapler, blue load, introduced through the right upper quadrant 12 mm trocar. The posterior phrenogastric ligament is dissected until the previous dissection is reached.

The linear stapler (blue load) is introduced in the left upper quadrant 12 mm trocar and aimed from the left lateral horizontal section level towards the angle of His. Two or three vertical firings of the stapler are performed to reach the His angle. This allows for complete detachment of the gastric pouch from the remnant.

6.2.2.5 Latero Lateral Mechanical Linear Gastrojejunal Anstomosis

The transverse colon is lifted in upwards to visualize the Treitz Angle. The reversed Trendelenburg position facilitates the identification of the Treitz angle.

The intestinal loop is lifted in an ante-colic position over some 100 cm to reach the oesogastric junction. The patient is replaced in a neutral position. An opening is created in the loop with the coagulating hook which allows the introduction of a blue load linear stapler. The stapling is realized parallel and as close as possible to the vertical staple of the gastric pouch. The opening is closed with two running sutures (PDS 2.0). The superior running suture is initiated at the summit of the stapling line and comprises the gastric pouch and anastomosis stapling line.

70 cm of bowel are measured on the alimentary loop, from the gastrojejunal anastomosis. The alimentary loop at this point is secured to the biliopancreatic loop with a suture (silk 2.0). The suture is held by a grasper and is elevated to reach the upper part of the stomach.

6.2.2.6 Mechanical Side to Side Jejunojejusnostomy

A linear mechanical jejunojejunostomy is performed. The opening is closed by two converting running sutures (PDS 2.0). The jejunum in between the two anastomosis is sectioned with a linear stapler with white load.

6.2.2.7 Closure of the Mesenteric Defect and of the Petersen Space

The mesenteric defect, between the alimentary and the biliopancreatic limbs must be closed after conclusion of the jejunojejunostomy. A purse string stitch (prolene 2/0 or 1) is used for this purpose. A purse string is preferred over a running suture because it allows more mobility of the anastomosis, hence avoiding kinking which is the usual cause of blow out of the remnant stomach.

6.2.2.8 Postoperative Management

Provided there is no evidence of a leak, the patient is allowed to drink water. On the third postoperative day the patient is discharged.

The patient is restricted to a semi-liquid diet for 1 week, followed by a pureed diet for another 4 weeks. An office visit is scheduled for around that time. When assessment is positive, the patient is advanced to a regular diet. Exercising is encouraged from the fifth postoperative week onwards. Patients are instructed to take either an H2 blocker or proton pump inhibitor, usually for up to 6 months.

6.3 Duodenal Switch

6.3.1 Principle of the Procedure

Biliopancreatic diversion with duodenal switch is primarily a malabsorptive procedure. The biliopancreatic diversion (BPD), pioneered in Genoa (Italy), is performed mainly in Europe The duodenal switch is an adaptation of the BPD and was developed in Canada and America. It consists of a combination of a sleeve gastrectomy and a BPD. A Roux- limb is anastomosed to the first part of the duodenum at one end, and to the transected bowel some 75–100 cm proximal to the ileocaecal valve at its other end. With the duodenal switch the mechanism of weight loss is double :

• 1. sleeve gastrectomy ensures restriction in the amount of calories taken by mouth

• 2. the functional shortening capacity of the bowel reduces the absorption capacity of the latter since the exchange surface is smaller. Moreover fat can only be digested once the biliary and pancreatic juices are mixed with the food which obviously occurs only quite distally.

6.3.2 Instruments

• 6 trocars: 3 trocars of 5 mm, 1 trocar of 10 mm, and 2 loads linear stapler

• 30° degree optical system

• Veres needle

• 4 atraumatic grasping forceps (2 with 5–10 cm marks)

• coagulating hook

• suction device

• scissors

• needle-holder (5 and 10 mm)

• Harmonic scalpel/Ligasure

• 60 mm (45 mm optional) linear stapler (6–7 black/green cartridges and 3–4 white cartridges)

• two stitches of PDS 1

• two stitches of PDS 2/0

• two stitches of Prolene 1 or 2/0

• one stitch of white Vicryl 3/0

• one stitch of Silk 210

• one stitch of Vicryl 2/0 and 1

• one stitch of Ethibond 2

6.3.3 Technique

6.3.3.1 Patient, Team and Trocars Position

The patient is placed in the supine position with legs apart. The patient is carefully strapped to the operation table and the arms are placed in abduction. Sequential calf compression is used. Shoulder supports are placed as well and extreme care is taken to pad the pressure points and joints with foam cushions. The table is tilted head up at some 10°. The surgeon (5) stands between the patient’s legs, the cameraman to the patient’s right (C) and the assistant to the patient’s [eft (A). Abdominal insufflation up to 16 mmHg is obtained with the insertion of a Veres needle at the patient’s left upper quadrant, or at the umbilicus. Trocars are placed as follows: a 10 mm trocar (Ti) 20 cm distal to the xyphoid process for the 30° optical system; a 5 mm trocar (T2) on the [eft anterior axillary line; a 12 mm trocar (T3) in the left upper quadrant on the mid clavicular line just between the 1″ and the 2 trocars; a 12 mm trocar (T4) in the right upper quadrant on the right mid clavicular line; a 5 mm trocar (T5), used for liver retraction, distal and to the left of the xyphoid process; a 5 mm trocar (T6) just to the left of the linea alba, midway between the umbilicus and the pubis.

6.3.3.2 Sleeve Gastrectomy

This step constitutes the first part of the procedure and has been described in detail in chapter 5.

6.3.3.3 Duodenal Section and Cholecystectomy

A cholecystectomy is performed and the gallbladder is retrieved by T3. Two methods are available for transection of the duodenum.

• ANTERIOR APPROACH: After identification of the pylorus, the anterior peritoneal sheet at the lower border of the first duodenum, across from the common bile duct, is dissected with the coagulating hook (A). A passage between the duodenum and the pancreatic head is created under direct vision. This permits the introduction of the linear stapler (white load) (T3) (B) and the duodenum is transected (D). The gastroduodenal artery should become visible at this stage

• POSTERIOR APPROACH: The stomach is held up and all retrogastric adhesions at the distal end of the antrum are divided with the coagulating hook. With gentle dissection a passage is created just anterior to the pancreatic head and to the gastroduodenal artery. The anterior and posterior edge of duodenum are dissected (A) and a grasper is introduced between them and severs the peritoneal sheet from posterior to anterior. A tape (Ethibond 2) is looped around the duodenum at that level, and facilitates in holding the first part of the duodenum upwards. A firing of a linear stapler (white load) (T3) divides the duodenum (C).

Regardless of the approach, a stitch (white Vicryl 3/0) is placed at the inferior angle of the proximal sectioned duodenum.

6.3.3.4 Measurement of Common, Alimentary and Biliopancreatic Loops

The patient is positioned in a 10° Trendelenburg position with a 100 right tilt. Surgeon and assistants are now positioned to the patient’s left (A-B). An appendectomy is performed and the appendix is retrieved by T4. The caecum is dissected off the parietal wall by the coagulating hook, in order to facilitate subsequent lifting of the alimentary loop. Starting at the ileo-caecal valve, the small bowel is measured for a distance of 75 or 100 cm. A PDS 2/0 stitch is placed on the bowel wall exactly at this level and fixed to the abdominal wall. The bowel distal to the stitch is marked gently with a coagulating hook (future common limb). From this point another 200 or 225 cm is measured, so that the sum of alimentary + common equals 300 cm. The bowel proximal to this point is marked with the coagulating hook (biliopancreatic limb) and a marking clip is placed just distal to this point (proximal end of the alimentary limb). A firing of stapler (white load) (T3) divides the bowel between the biliopancreatic and the alimentary limbs (C-D).

6.3.3.5 Jejunoileostomy: Semi-mechanical Side-to-Side

The bowel at the 75–100 cm marking (the marks will help to remain oriented) is sutured to the biliopancreatic limb, using the same stitch that was fixed into the parietal peritoneum. The common and biliopancreatic limbs are opened by the hook (A). A linear stapler (white load) (T3) joins the two limbs (B). The enterotomy opening is closed by a running suture (PDS or silk 2/0) with two separated suture lengths starting at each corner which are then tied together (CD).

6.3.3.6 Closure of the Mesenteric Defect

The mesenteric defect, located between the common and the biliopancreatic limbs, is closed after performance of their anastomosis. A purse string stitch (Prolene 2/0 or 1) is used to close this defect in order to prevent an internal hernia.

The patient is re-placed in the reversed Trendelenburg position. The surgeon returns between the patient’s legs, the cameraman to the patient’s right and the assistant to the patient’s left (A-B).

6.3.3.7 Duodenoileostomy Totally Handsewn End- to-Side

The surgeon places himself again between the legs of the patients, the two assistants on either side. The alimentary limb is moved up in the direction of the duodenum. A running suture (PDS 1) is initiated on the superior corner of the transected duodenum and successive bites are taken alternatively on the duodenum and on the alimentary limb. This suture line constitutes the posterior layer of the anastomosis (A). A new running suture (PDS1) starting on the superior corner initiates the anterior layer of the anastornosis; the duodenum and the small bowel are opened with the coagulating hook (B). The posterior running suture is carried over the inferior corner of the anastomosis and is driven onto the anterior layer for a short distance (C). Finally the two running sutures are joined together halfway on the anterior layer and tied (D).

6.3.3.8 Closure of the Petersen’s Space

The Petersen’s space, a potential defect formed as a result of the procedure between the alimentary limb and the transverse rnesocolon, has to be closed in order to prevent an internal hernia. A purse string stitch (prolene 2/0 or 1) is used to this purpose.

6.3.3.9 Leak-Test of Both Anastomosis

A gastric tube is pushed down by the anaesthesiologist into the sleeve gastrectomy until it reaches the pylorus. The patient is placed in Trendelenburg position. The operating field is immersed in saline solution. Compressed air is insufflated into the gastric tube by the anaesthesiologist. The absence of air bubbles is testimony of the integrity of the sleeve gastrectomy and of the duo-denoileostomy. Subsequently the surgeon manipulates the entire alimentary limb until the air reaches the jejunoileostomy and compressed air is used again to test the integrity of the common, the alimentary and the biliopancreatic limbs. The procedure is concluded by the positioning of two drains, one near the sleeve and one near the duodenoileostomy and the 12 mm left trocar site is closed with absorbable suture (vicryl 1).

6.3.3.10 Postoperative Management

First postoperative day: methylen blue test is performed. If there is no evidence of a leak the patient may drink water.

Third postoperative day: gastrograffin swallow is performed only if there is suspicion of a leak. If not, the patient can start a liquid diet.

Fourth postoperative day: the drain is taken out and the patient is discharged if fit.

The patient is put on PPI IV for 24 h, followed by the same drug orally for 6 months. The patient is restricted to a semi-liquid diet for 1 week, followed by a pureed diet for another 4 weeks. An office visit is scheduled at around that time. If patient progress is good, the patient is allowed a regular diet. Sweets, alcohol and carbonated drinks are prohibited. Exercising is encouraged from the fifth postoperative week on. At 4 weeks, the patient receives follow up nutritional counseling for a protein-enriched diet and is given twice-daily multivitamins, oral calcium supplements, iron and fat-soluble vitamins (A, D, E, K). Laboratory evaluation for nutritional deficiencies is performed at each visit, including iron, ferritin, vitamin B12, folate, albumin, PTH, calcium, alkaline phosphatase, zinc, selenium, lipid profile, vitamin A and D levels, electrolytes, total proteins, and albumin. Liver enzymes and routine hematology are also included.

7 Follow Up

Obesity is a life long disease. “The fat cell never dies”. Despite all surgical efforts, the patient will have a tendency to regain weight. The weight regain phenomenon usually occurs as of the third postoperative year. The weight regain issue as well as the potential complications linked with the surgery should be addressed by a multi disciplinary team that acts in synergy. To assure long term weight maintenance the team must encourage the persistence of the patient’s life style changes initiated by the surgery, and, more specifically, help the patient to persevere in daily physical activity and good dietary choices. The following parameters should be monitored on the long term:

• 1. Nutritional management

• 2. Weight loss

• 3. Comorbidities that may have disappeared initially

• 4. Nutritional status to avoid malnutrition. Should be monitored especially: plasma protein, Potassium, Cholesterol

• 5. Vitamin and mineral deficiency. Should be monitored especially: Iron, Calcium, PTH, the water soluble vitamins A, D, E and K, the vitamins B1,B6 and B12, Zinc, Magnesium and Selenium

• 6. Medical symptoms after surgery: vomiting, dumping syndrome and hypoglycemia, neurological symptoms

• 7. Late surgical complications: gall stones, intestinal obstruction (internal hernia, trocar hernia), stoma complications (erosion, ulceration, dilation), candy cane formation, gastro-intestinal bleeding

• 8. Psychological issues (anxiety, depression)

• 9. Physical activity, if possible in cooperation with a trainer or physiotherapist

The patient should be seen by the surgeon at least once a year, by the medical nutritionist at least three times a year, and by the psychologist whenever needed.