Overview of Sleeve Gastrectomy
Obesity, being extremely overweight, has become more and more common in the United States in the last 50 years. Shockingly, over 98.7 million people in the US are now affected by it. In fact, in 2014, managing health problems related to obesity took up 14.3% of the country’s health care spending. To deal with obesity, one of the most effective and long-lasting solutions is weight loss surgery, which has been getting better and more advanced.
There are many types of weight loss surgeries, and one of the most popular is called sleeve gastrectomy. This surgery was first done in 1990. Originally, it was the part of a two-step operation known as biliopancreatic diversion with duodenal switch (BPD-DS). The first time a sleeve gastrectomy was done using a less invasive method, laparoscopic surgery, was in 1999. They initially used this surgery for patients who were extremely obese (with a Body Mass Index >60) to help them lose weight and be able to handle the second part of the BPD-DS operation more safely.
While monitoring patients who had undergone the sleeve gastrectomy, doctors noticed that they were losing a lot of their extra body weight. In 2008, guidelines were published outlining who would be good candidates for laparoscopic sleeve gastrectomy (LSG). Compared to other weight-loss surgeries, sleeve gastrectomy is simpler and comes with lesser risks, making it the most common weight loss surgery done in the United States.
Anatomy and Physiology of Sleeve Gastrectomy
If you want to understand how a type of weight-loss surgery called a sleeve gastrectomy works, it’s important to know a bit about the anatomy of the stomach, the structures around it, and how it gets its blood supply.
The stomach is a muscular tube that starts just under the left lung at the stomach’s entry point, where it connects with the esophagus, and continues to a section of the small intestine called the duodenum. The stomach has several parts: the cardia, which is closest to the esophagus; the fundus, which lies underneath the diaphragm; the body, which is the main part of the stomach; the antrum, which is the lower part; and the pylorus, which is the part that connects to the small intestine.
The stomach has two curved borders. The smaller, right curve (lesser curvature) is beneath parts of the liver, and the larger, left curve (greater curvature) is next to the body wall on the left and is connected to a piece of fat-filled tissue called the greater omentum. Where the esophagus enters the abdomen and the top part of the stomach meet is a sharp bend called the “angle of His”. Behind the stomach is a small space directly in front of the pancreas.
Various ligaments (tough bands of tissue) help keep the stomach in place including the gastrohepatic ligament, gastrophrenic ligament, gastrosplenic ligament, and gastrocolic ligament. All these ligaments connect the stomach to different neighboring organs like the liver, diaphragm, spleen, and the part of the large intestine called the transverse colon.
The stomach gets its blood supply from a large artery called the celiac trunk, which has branches that supply various parts of the stomach with blood. The left and right gastric arteries supply the upper curve of the stomach. The left gastric artery is particularly important during a sleeve gastrectomy because it provides most of the blood supply to the stomach. The right gastric artery is supplied from a branch of the liver’s artery and meets with the left gastric artery. The parts of the stomach on the left curve receive blood from the right gastroepiploic and left gastroepiploic arteries. The top part of the stomach also gets blood supply from 3 to 5 short gastric arteries from the spleen.
Why do People Need Sleeve Gastrectomy
Sleeve gastrectomy is a type of weight loss surgery, which may be suggested for certain individuals who are extremely overweight. The common criteria considered for picking viable candidates for such surgeries include:
1) Having a Body Mass Index(BMI) of 40 or above, or a BMI of 35 or above but also suffering from conditions related to obesity (such as high blood pressure, type 2 diabetes, or severe issues with the musculoskeletal system – the body’s system of muscles and bones).
2) Making several unsuccessful attempts to lose weight without surgery.
3) Being mentally fit to undergo surgery as per a mental health check-up.
4) Not having any medical conditions that would make surgery risky.
Recent considerations for this procedure also include patients with a BMI of 30-35 who are struggling to control their type 2 diabetes or who have metabolic syndrome – a group of conditions that increase the risk of heart disease, stroke, and type 2 diabetes. They may also be considered for a laparoscopic sleeve gastrectomy, which is a less invasive procedure where small incisions are made and a camera is used to guide the surgery.
When a Person Should Avoid Sleeve Gastrectomy
There are some conditions where certain medical procedures shouldn’t be done. For example, if someone can’t handle general anesthesia, which puts them to sleep for surgery, they shouldn’t undergo certain operations. The same is true for those with an uncontrollable blood clotting issue, known as coagulopathy, or severe mental health conditions.
Also, in some cases, medical procedures might only be risky rather than completely off-limits. This is the case for people who have Barrett’s Esophagus, a condition where the tissue lining the esophagus changes due to repeated burning from stomach acid. Likewise, severe cases of gastroesophageal reflux disease, a type of chronic acid reflux, might also make a procedure more risky.
Equipment used for Sleeve Gastrectomy
For the surgery, we need certain specialized equipment. This includes things to inflate your belly with CO2 gas (this makes it easier to see and work), some surgical covers or drapes, screens to see what we’re doing, surgical tools that can be used through small holes, an electrocautery device (this uses electricity to cut tissue or stop blood vessels from bleeding), and trocars (those are the tubes that we insert into your belly for the operation).
Because people having weight loss surgery often have thicker belly walls, we need longer trocars and tools than we’d use for other types of laparoscopic surgery (which is surgery done through small holes rather than a big cut).
We’ll also use:
- Four trocars, three which are 5 mm in size and one which is 15 mm.
- A tool to hold your liver out of the way.
- A special surgical camera that lets us see everything clearly from an angle.
- A device to join tissues together with staples.
- A tube, about 32 to 40 French in size (that’s a measurement we use in medicine), to guide us during the procedure.
- A flexible camera to check our work and make sure everything is okay.
- A device to safely deliver energy for cutting and controlling bleeding.
Who is needed to perform Sleeve Gastrectomy?
Before qualifying for weight loss surgery, a patient must undergo evaluation from a team of different medical professionals. This team includes a nutritionist (expert in food and diet), a psychiatric specialist (mental health expert), a surgical team, and a primary care doctor (your usual health provider).
During the surgery itself, four key members are needed for the procedure: an anesthesiologist (doctor responsible for the medicine that puts you to sleep), a metabolic surgeon (a surgeon trained in weight loss surgery), a scrub nurse (a nurse who assists in surgery), and a first assistant (another professional who helps the surgeon).
Preparing for Sleeve Gastrectomy
Being severely overweight can cause many health issues for women. It can make their menstrual cycles irregular and make it harder to get pregnant. Women with severe obesity are also at a higher risk of complications during pregnancy, like gestational diabetes and high blood pressure. Also, the baby may grow to be larger than normal. To prevent these problems, organizations such as the American Society for Metabolic & Bariatric Surgery suggest avoiding getting pregnant before and for around a year to a year and a half after weight-loss surgery.
This caution is due to the fact that the quick weight loss and potential lack of vital vitamins and minerals following the surgery might impact the growing baby. The mother’s health could also be affected due to the risk of malnutrition that comes with rapid weight loss.
The American College of Obstetricians and Gynecologists suggest using non-pill birth control methods, like hormonal IUDs or implants, for women who’ve had weight-loss surgery and are looking for hormonal birth control. Barrier methods of contraception like condoms also help in preventing sexually transmitted diseases. The physical and physiological changes that come with weight loss surgery might increase the chance of birth control pills not working. Also, birth control pills increase the risk of blood clots in overweight patients.
Before surgery, patients should undergo an examination of the upper digestive tract – the esophagus, stomach, and upper small intestine. Also, following a very low-carb diet could help shrink the liver before surgery, which could lead to better outcomes.
Before the start of the surgery, the patient will be given antibiotics and be treated to prevent blood clots. They will also have the hair on their stomach removed. Once on the operating table, the patient will be secured in place, and a tube will be placed in the stomach after anesthesia is administered.
How is Sleeve Gastrectomy performed
A laparoscopic sleeve gastrectomy is a type of weight loss surgery that is performed with small incisions and special tools. Here’s an example of how this procedure generally works, though every patient’s case can be different.
To start with, the surgeon will make an entry into your abdomen, usually on the left upper part, by making a small incision or cut. After that, your abdomen will be filled with gas to create space for the surgeon to see and work. A laparoscope – a thin tube with a camera – is then used to look around inside your abdomen. The surgeon will make a few more small cuts to place other medical instruments needed for the operation.
The surgeon starts by separating the fatty layer attached to the stomach and then cuts the blood vessels along the curvature of the stomach. The surgeon will make the cut at a variable distance from a part known as the pylorus, based on careful evaluation. The part of the stomach being cut off will determine how much weight you might lose after the surgery.
In some cases, a small hernia may be found in the diaphragm, around the food-pipe area. If the hernia is present, the surgeon will repair it. Next, the surgeon will move the stomach to expose its back wall and cut any connections on the back side of the stomach.
Then, a special tube called a bougie is inserted through your mouth down to the stomach. This tube helps to guide the surgeon in making the appropriate size for the new stomach. The exact size of the bougie used can vary as smaller bougies might increase the risk of post-surgery complications, but would also help in weight loss.
The creation of the new stomach or “sleeve” happens by placing staples along the length of the bougie, which allows for the excess part of the stomach to be removed. The remaining part of the stomach forms a tube-like structure that is much smaller than the original size of the stomach. This smaller stomach reduces food intake and leads to weight loss.
The safety of the surgery is extremely important, so the surgeon will use various methods to prevent any bleeding from the staple line. Sometimes, after making the new stomach, the surgeon might use a special type of stitches to further secure the end of the stomach. An endoscope, another type of tube with a camera, is used to check for any leaks from the staple line to ensure everything is alright.
To end the procedure, the surgeon closes all the small cuts made at the beginning of the surgery. A final check is done to make sure that everything is intact, and then the gas is released from your abdomen.
This process, from start to finish, works towards ensuring you have a safe and effective weight loss procedure, with the end goal of improving your health and quality of life.
Possible Complications of Sleeve Gastrectomy
Laparoscopic sleeve gastrectomy, a type of weight loss surgery, has a risk of complications within 30 days of 0-17.5% and a risk of death of 0-1.2%.
Complications can happen soon after the operation (early) or some time later (late).
Early complications:
– Hemorrhage: This is when there’s too much bleeding, which happens in 1 – 6% of patients. It can occur inside or outside of the digestive tract. If the bleeding is outside, it could come from the area where the staples were used, the spleen, liver, or the abdominal wall. Treatment may require another operation. If the bleeding is inside, the patient might experience dark, tarry stools or vomit blood, along with a drop in red blood cell count. This may be managed using a procedure to look inside your digestive tract and occasionally needs surgery.
Some evidence suggests that reinforcing the staple line can prevent bleeding. Specific reinforcing materials are more effective than stapling alone, but more research is needed.
– Leak: This happens in 2-3% of cases, when liquid leaks out from the staple line due to excess pressure and lack of blood supply. It often happens just below the junction connecting the esophagus and stomach because that’s where the blood supply gets cut off during the operation. Problems could come up if the tools used in surgery are too small or if the stapler is applied too close to the incision. Studies have shown using wider tools lower the chances of leaks but more research is needed to confirm.
Patients may feel fine, but could also experience fever, rapid heart rate, and rapid breathing. Typically, a CT scan is used to diagnose the leaks. If the leak is new and the patient is unstable, drain the leaked fluid and place a feeding tube in the patient’s stomach. For a chronic leak, wait out to see if the situation improves while draining any abscess formed and giving antibiotics as needed.
Late complications:
– Stricture: This is when the passage into or out of the stomach gets narrow, happens in up to 4% of patients. This can show up acutely due to swelling or more often over time. Patients may experience difficulty swallowing, nausea, and vomiting. This is often diagnosed using a contrast study where a dye is drunk by the patient and then X-ray images are taken. Initial treatment usually involves inflating a balloon inside the stricture to stretch the passage. If this doesn’t work, the patient may require another surgery.
– Gastroesophageal Reflux: This is when the stomach acid flows back into the esophagus causing heartburn. This could develop or get worse following the surgery. Initially, doctors would prescribe medicine to reduce the acid production. If the reflux is severe and the medicines are not working, the patient could require another surgery where the stomach is connected to the lower part of the small intestine.
– Nutritional Deficiencies: All weight loss surgeries risk nutritional deficiencies which are generally prevented by regular testing and supplements. Sleeve gastrectomy has a lower risk of this compared to gastric bypass, a different type of weight loss surgery, except for deficiency in folate (a type of vitamin B).
If a patient shows symptoms of thiamine deficiency such as encephalopathy (a brain disease), oculomotor findings (problem with eye or eye lid movements), signs of cerebellar impairment (problems with balance, coordination, and speech), psychosis, confabulation (making up experiences), it should be treated immediately even before diagnosis is confirmed. Then they should be monitored constantly to see if the symptoms are improving.
What Else Should I Know About Sleeve Gastrectomy?
The laparoscopic sleeve gastrectomy, a type of weight loss surgery, has become increasingly popular in the United States over the past twenty years. Recent long-term studies show very promising results. People who have this surgery typically lose about 60% of their extra weight within five years, and it also significantly improves associated health conditions (comorbidities).
A 2017 research report compared the outcomes of sleeve gastrectomy with another type of weight loss surgery called roux-en-y gastric bypass. They found that both surgeries led to similar weight loss and improvement in health conditions in the medium-term (3-5 years after the surgery).
However, in the long term, the gastric bypass surgery led to slightly more weight loss. Still, both surgical procedures were equally effective in improving health conditions. To sum up, if you’re considering weight loss surgery, both these options can help you lose a significant amount of weight and improve your overall health in the long run.
