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Laparoscopic Roux-en-y Gastric Bypass

mr James Kellymr James Kelly

Laparoscopic Roux-en-y Gastric Bypass

Laparoscopic Roux-en-y Gastric Bypass is a minimally invasive weight loss (bariatric) surgical procedure. It involves the formation of a gastric pouch, enabling food to bypass much of the original stomach. It is one of the most commonly performed bariatric procedures and is associated with the highest rates of postoperative weight loss compared to the other procedures.

The surgery is performed under general anaesthetic and recovery usually takes up to 4 weeks, during which time the patient is placed on a liquid diet to aid recovery.

Complications of the surgery range from postoperative leakage which can occur even after 12 weeks, alongside more serious complications such as stenosis and ulcer formation. Dumping Syndrome is also a common complaint after the procedure and usually resolves within 7 - 12 weeks.


A Laparoscopic Roux-en-y Gastric Bypass (LRYGB) is a minimally invasive bariatric (weight loss) surgical procedure. It is the current gold standard bariatric procedure, and has been proven to result in the highest levels of postoperative weight loss out of all the different surgeries (1). It is a restrictive bariatric procedure, and hence works by limiting the amount of food that a person can eat by making them feel more full. The procedure involves conversion of the stomach into a small pouch which is then connected directly to the small intestine; as a result of which food is passed directly from the oesophagus into the pouch, and then into the small intestine. Hence the ingested food bypasses most of your stomach through its journey in the gastro-intestinal system (2).


LRYGB is conducted to help lose weight, particularly in patients where previous medical or lifestyle treatment hasn’t worked. Typically patients will have a BMI more than 40, where the obesity is severe. However, the procedure is also conducted in patients with a BMI between 35 - 40 who present with one or more serious complications of obesity, such as:

  1. Gastroesophageal reflux disease (GORD)
  2. Chronic Heart Disease
  3. Hypertension (High blood pressure) and High Cholesterol
  4. Obstructive sleep apnoea
  5. Type 2 diabetes
  6. Stroke
  7. Infertility (3)

You will be assessed by a multidisciplinary team involving dietitians, bariatric surgeons, and psychologists to ensure that the procedure is safe and right for you.


LRYGB has been shown to be very effective regarding postoperative weight loss. Studies have shown how the average excess weight loss is between 70% - 75%, with a sustained weight loss of 60% - 70% over five years (4).

If you have uncontrolled type II diabetes, LRYGB has been shown to be particularly effective at treating insulin resistance when compared to the other bariatric surgeries, and results in lower rates of relapse (5). Studies have shown how 80% of diabetic patients maintain glucose control after a LRYGB compared to 0% for just medical treatment. Part of this success is to do with the weight loss, but part of it is attributed to an unknown mechanism whereby bypassing the majority of the stomach and beginning of the small intestine decreases insulin resistance (6). Hence your doctor will take this into account when deciding whether or not to proceed with a LRYGB. Furthermore, many surgeons prefer performing a LRYGB over a sleeve gastrectomy in patients with severe Gastroesophageal reflux disease or evidence of Barrett’s Oesophagus to reduce the risk of complications. Studies have shown a 50% reduction in prevalence of reflux disease after a LRYGB procedure (7).



The preparation for bariatric surgery is often comprehensive, and involves both a psychological and physical component. This is performed in conjunction with nutritional assessments, and hence the preparation for bariatric surgery often involves multiple members of the multidisciplinary team.

An important aspect of bariatric surgery is ensuring that you are able and willing to make the lifestyle changes for the weight loss to be sustainable. Hence the psychologist will take into account factors such as previous attempts at weight loss, substance abuse, risky eating habits, and physical activity levels to assess whether you have the motivation required to make the necessary changes before and after surgery. The doctor will give you the appropriate advice to help you in this process, and may refer you to specialist nutritional and psychological services which will offer more specific help.

You will also have to undergo a comprehensive medical assessment to investigate for any other comorbidities such as hypertension, lung disease, and obstructive sleep apnoea. The doctor will assess any medications you are currently taking as these may need to be temporarily stopped in the period surrounding your surgery to reduce the risk of bleeding. These include anticoagulant medications such as warfarin and clopidogrel.

If you have Gastroesophageal reflux disease, the surgeon may want to perform an Esophagogastroduodenoscopy (OGD). This will allow for any Barrett’s Oesophagus to be identified which should be treated before the surgery is scheduled to take place. An EGD is an endoscopic procedure regularly conducted in patients who are being considered for bariatric surgery. It involves inserting a thin tube with a camera into your mouth and then down your oesophagus. This allows the surgeon to assess for any other diseases within the oesophagus such as oesophagitis, as well as to test the patency of the gastroesophageal junction flap allowing entry of food contents into the stomach.You will be prescribed a low-calorie liquid diet to adhere to 1-4 weeks before the surgery is scheduled to take place. This is performed to help reduce the stiffness and size of the liver, which makes the operation easier and safer to perform (8).


The surgery is carried out under general anaesthetic, which means that you will be unconscious throughout the surgery. For this reason, you will need to have an endotracheal tube placed down your throat to help you breathe during the procedure (see diagram below). You will have an appointment with the anaesthetist before the surgery where you can discuss any concerns or queries you may have, and go through any on the day procedures. Obesity can impact the delivery of anaesthetic, and the anaesthetist may have to make adjustments to normal practice, such as using a ramp to allow some body fat to move away from your head and neck.


On the day of the surgery, you will be given antibiotics one hour before the surgery is expected to start. This reduces the chances of any wound or internal infection. You will also be fitted with a mechanical compression stocking on each leg, which will periodically compress your legs during the surgery to prevent any blood clots forming (Deep Vein Thrombosis). The steps of the surgery are as follows: 

1) Once the anaesthetic has had its effect, you will initially be placed in the supine position (lying on your back). This is to allow the surgeon the best possible exposure to make the incisions. You will also have your legs strapped to the operating table to prevent any sliding. If the surgery is expected to take longer than usual due to the presence of other comorbidities, you may have a urinary catheter placed inside your bladder to allow urine to drain out and for your hydration levels to be monitored. 

 2) An orogastric tube will be placed through your mouth and oesophagus into the stomach. This is to allow decompression of the stomach and for any remaining stomach contents to be removed. This orogastric tube will be removed once the surgeon begins to make the pouch. 

3) At this stage of the procedure, the surgeon can begin to make the incisions. The exact incision location depends upon the preference of the surgeon, but typically five incisions will be made at various places of the abdomen. 

4) The surgeon begins by using a laparoscope (thin tube with a camera on the end) to see inside the abdomen and check for any damage to the internal organs caused by trocar insertion as the incisions were made. 

5) The next step involves identifying the falciform ligament of the liver. This ligament is divided to allow easy visualisation of the upper abdomen. Any adhesions to the abdominal wall are divided to allow the small intestine and transverse colon to be mobilised. 

6) The surgeon then enters the lesser sac which is a cavity in the abdomen. This is done through the use of an electrosurgical device. The tissue which connects the posterior abdominal wall to the transverse colon (transverse mesocolon) is then entered using a similar procedure. 

7) The surgeon then begins to measure a portion of the jejunum (the middle portion of the small intestine) which is then divided using staplers. The surgeon takes care at this stage to avoid stapling too close to the mesentery, which may result in small bowel ischaemia. 

8) A side to side anastomosis (join) between the two portions of the small intestine is then made using a suture. You will now be placed in the steep reverse trendelenburg position for the rest of the surgery to allow the surgeons to operate safely. 

9) The surgeon will now move to mobilising the fundus (top portion of the stomach) to ensure that the gastric pouch is not too large. The stomach is divided into two, forming a gastric pouch alongside the remnants of the stomach. This is done using a stapling device. At this point, all tubes and probes will be removed from your mouth to avoid these being divided and left in your stomach. 

10) The gastric pouch is connected to the jejunum (anastomosis) using a stapled technique alongside hand sewing. Once this join has been made, the surgeons will test for any leaks in any of the anastomosis. 

11) Once the surgeon is confident that no leaks are present, potential hernia sites are closed using permanent sutures. This reduces the risk of post-operative hernia formation. 

12) All equipment is removed and using laparoscopic guidance local anaesthesia is given to reduce postoperative pain control (9). 


As described this is a big procedure and the surgery time is around 3 hours but then there is the anaesthetic time of going to sleep and the recovery from the anaesthetic so in all, it takes most of the day. 


After the operation, you will be taken to a recovery room where you will be woken up and closely monitored. It is common to feel postoperative nausea after a LRYGB procedure, and hence you will be given intravenous antiemetics such as ondansetron to help with this. On the day after your procedure, the doctors will test once more for any leaks using a leak test using a contrast dye scan. If there are no leaks present, you will be given water to drink every hour. Once you can tolerate water well, you will be moved onto a clear liquid diet on day 2, alongside a full liquid diet once you are comfortable. You will be kept in hospital until you can tolerate a full liquid diet well and your pain is controlled.

During your stay in hospital, you will be closely monitored for any Deep Vein Thrombosis. You will also be guided on deep breathing exercises to prevent any lung collapse that may occur from shallow breathing due to postoperative pain (atelectasis). Antibiotic therapy will be continued for 24 hours.


This varies patient to patient but as a rough guide 4-7 days. 


You will be asked to stay on a full liquid diet for two weeks or until your first postoperative follow up appointment. At this stage, you can move onto a soft diet. Before discharge, you will meet the dietician who will give you advice on the different types of food you can eat at each stage. It is important you stay well hydrated to help with the healing process.







It is a good idea to have someone stay with you at home for one night if you live alone. 


You will be given a course of proton pump inhibitors to take for up to three months to reduce the risk of ulcer formation in the newly formed gastric pouch. The removal of a large portion of the stomach means that you will be required to take nutritional supplements to compensate. These include iron and calcium supplementation, which will be prescribed to you on discharge. Your doctor will likely request you to have regular blood tests to ensure that your vitamin levels are kept within the healthy range. You may also be given regular lifelong Vitamin B12 injections which take place every 6 months.

It is important to stay healthy during your recovery to ensure that the operation is successful. This includes incorporating regular physical activity in your day, and choosing food and drinks which are low in calories. Small but regular meals are also encouraged over large meals 3 times a day; this allows your body time to process and digest the food and reduces the chance of diarrhoea and bloating after eating a heavy meal. This also helps to reduce the risk of stretching the stomach pouch, which can reverse the desired effects of the surgery as you will feel the need to eat more.


You will have a follow up appointment with the surgeon between 4-6 weeks after surgery to check on your recovery progress. This is a good time to raise any concerns or questions that you may have.