User:HrndzJuror/Gastrectomy

Lead
A gastrectomy is a partial or total surgical removal of the stomach.

Indications
Gastrectomies are performed to treat stomach cancer and perforations of the stomach wall such as tumors, ulcers, or other types of stomical damage. Laparoscopic surgery may also be performed in order to achieve this.

In severe duodenal ulcers it may be necessary to remove the lower portion of the stomach called the pylorus and the upper portion of the small intestine called the duodenum. If there is a sufficient portion of the upper duodenum remaining a Billroth I procedure is performed, where the remaining portion of the stomach is reattached to the duodenum before the bile duct and the duct of the pancreas. If the stomach cannot be reattached to the duodenum a Billroth II is performed, where the remaining portion of the duodenum is sealed off, a hole is cut into the next section of the small intestine called the jejunum and the stomach is reattached at this hole. As the pylorus is used to grind food and slowly release the food into the small intestine, removal of the pylorus can cause food to move into the small intestine faster than normal, leading to gastric dumping syndrome.

History
The first successful gastrectomy was performed by Theodor Billroth in 1881 for cancer of the stomach.

Historically, gastrectomies were used to treat peptic ulcers. These are now usually treated with antibiotics, as it was recognized that they are usually due to Helicobacter pylori infection or chemical imbalances in the gastric juices.

In the past a gastrectomy for peptic ulcer disease was often accompanied by a vagotomy, to reduce acid production. This problem is now managed with proton pump inhibitors.

In Japan, Tokyo University's Kintoji Shigeru succeeded in the first pyloric side gastrectomy in Japan in 1897, and Miyake Hideo reported the success of the total gastrectomy in 1918, and Tetsuo Maki of Tohoku University developed the Pilluminal Preserved Gastrectomy (PPG) in 1967.

Timeline
1881: Successful gastrectomy by Theodore Billroth

1885: Billroth II was first performed

1893: Gastrectomy reconstruction by the Roux-en-Y method was performed for the first time.

1897: In the same year, George Schlatter performed the first successful gastrectomy, and Jan Mikulicz-Radecki performed a lateral gastrectomy for the first time

1923: The Borrmann Classification for Stomach Cancer was devised.

1942: Kaoru Kajiya advocated broad lymph node purification

1950: Inventions of the Gastric Soft Mirror (Gastric Camera)

1961 Inventions of Gastric Double Imaging

1983: The discovery of Helicobacter pylori bacteria.

1987:  Erich Mühe performed laparoscopic cholecystectomy.

1994: Kitano Shigou Announces Gastrectomy of Parole Under Laparoscopic Assisted

Types of Gastrectomy Operations
The many types of gastrectomy can be put into the following categories: partial and total gastrectomy. In addition to those two categories, there is also pyloric side gastrectomy, pyloric preserved gastrectomy, jet side gastrectomy, gastric segmentectomy, and gastric local resection. Most of these operations are used for cases of gastric cancer.

The approaches include laparoscopic gastrectomy and laparotomy. In addition to gastric resection, lymph node dissection is performed for root healing purposes in gastric cancer.

Total Gastrectomy
Total gastrectomy is an operation to remove the entire stomach including the pylorus and the cardia [3] and reconstruction is done using a method using the Roux-en-Y method [5], the jejunum interposition method [5] and the double tract method [3].

Polya’s Operation
Also known as the Reichel–Polya operation, this is a type of posterior gastroenterostomy which is a modification of the Billroth II operation developed by Eugen Pólya and Friedrich Paul Reichel. It involves a resection of 2/3 of the stomach with blind closure of the duodenal stump and a retrocolic gastro-jejunal anastomosis.

Distal gastrectomy
Distal gastrectomy is the most common method of gastrectomy in surgery to remove two-thirds to four-fifths of the pylorus side of the stomach [6][4]. For reconstruction, Billroth I method [6], Roux-en-Y method [6], Billroth II method [6], and jejunal interposition method [3] are used.

Conserved Gastrectomy of the Pylorus
Although a pyloric conservation gastrectomy (PPG) is also a pyloric side gastrectomy, it is a method of leaving a part of the side of the stomach behind [4].

Proximal Gastrectomy
A proximal gastrectomy is an operation in which the ejector side of the stomach is removed by about a third to a quarter [4]. A jejunal placement method is commonly used for reconstruction [7].

Local Gastrectomy
Local gastrectomy is no longer a routine method because the adaptation targets are often overlapped due to the spread of endoscopic submucosal delamination (ESD).

Post-operative effects
The most obvious effect of the removal of the stomach is the loss of a storage place for food while it is being digested. Since only a small amount of food can be allowed into the small intestine at a time, the patient will have to eat small amounts of food regularly in order to prevent gastric dumping syndrome.

Dumping syndrome can undergo different stages. In early dumping syndrome, unprecedented large amount of food into the small intestine can cause a rapid rise in blood sugar. Symptoms include palpitations, dizziness, dizziness, and nausea. Late dumping syndrome causes hypoglycemia due to excessive secretion of insulin to steep hyperglycemia [12]. Symptoms include sweating, fatigue, dizziness and dizziness. It can also be improved by taking 90 minutes to eat slowly or increasing the number of meals to about five times a day.

In addition to this, most patients undergo weight loss, for up to 12 months post-surgery the amount of which varies from patient to patient.

Another major effect is the loss of the intrinsic-factor-secreting parietal cells in the stomach lining. Intrinsic factor is essential for the uptake of vitamin B12 in the terminal ileum and without it the patient will suffer from a vitamin B12 deficiency. This can lead to a type of anaemia known as megaloblastic anaemia (can also be caused by folate deficiency, or autoimmune disease where it is specifically known as pernicious anaemia) which severely reduces red-blood cell synthesis (known as erythropoiesis, as hyperglycemiar haemotological cell lineages if severe enough but the red cell is the first to be affected). This can be treated by giving the patient direct injections of vitamin B12. Iron-deficiency anemia can occur as the stomach normaweightts iron into its absorbable form.

Another side effect is the loss of ghrelin production, which has been shown to be compensated after a while. Lastly, this procedure is post-operatively associated with decreased bone density and higher incidence of bone fractures. This may be due to the importance of gastric acid in calcium absorption.

Post-operatively, up to 70% of patients undergoing total gastrectomy develop complications such as dumping syndrome and reflux esophagitis. A meta-analysis of 25 studies found that construction of a "pouch", which serves as a "stomach substitute", reduced the incidence of dumping syndrome and reflux esophagitis by 73% and 63% respectively, and led to improvements in quality-of-life, nutritional outcomes, and body mass index.

After Bilroth II surgery, a small amount of residual gastric tissue may remain in the duodenum. The alkaline environment causes the retained gastric tissue to produce acid, which may result in ulcers in a rare complication known as retained antrum syndrome.