Bowel resection | |
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Other names | Enterectomy, Colectomy |
Specialty | Gastroenterology |
A bowel resection or enterectomy ( enter- + -ectomy ) is a surgical procedure in which a part of an intestine (bowel) is removed, from either the small intestine or large intestine. Often the word enterectomy is reserved for the sense of small bowel resection, in distinction from colectomy, which covers the sense of large bowel resection. Bowel resection may be performed to treat gastrointestinal cancer, bowel ischemia, necrosis, or obstruction due to scar tissue, volvulus, and hernias. Some patients require ileostomy or colostomy after this procedure as alternative means of excretion. [1] Complications of the procedure may include anastomotic leak or dehiscence, hernias, or adhesions causing partial or complete bowel obstruction. Depending on which part and how much of the intestines are removed, there may be digestive and metabolic challenges afterward, such as short bowel syndrome.
Types of enterectomy are named according to the relevant bowel segment:
Procedure | Bowel segment | Notes |
---|---|---|
duodenectomy | duodenum | |
Whipple | duodenum and Pancreas | |
jejunectomy | jejunum | |
ileectomy | ileum | |
colectomy | colon | |
The anatomy and surgical technique for bowel resection varies based on the location of the removed segment and whether or not the surgery is due to malignancy. The below sections describe resection for non-malignant causes. Malignancy may require more extensive tissue resection beyond what is described here.
Bowel resection may be done as an open surgery, with a long incision in the abdomen. It may also be done laparoscopically or robotically by creating several small incisions in the abdomen through which surgical instruments are inserted. [2] [3] [4] Once the abdomen is accessed by one of these methods the surgery may proceed.
Once the abdomen is accessed, the surgeon "runs" the small bowel, viewing the entire small bowel from the ligament of treitz to the ileocecal valve. This allows for total evaluate of the small bowel to identify any and all pathologic sections. Once the area of concern is located, two small holes are created in the mesentery on either end of the segment. These holes are used to place a surgical stapler across the bowel and separate the segment of injured bowel from the healthy bowel on each end. Then bowel is then dissected away from the mesentery. Following this the remaining bowel is observed to verify continued blood flow. After resection the surgeon will create an anastomosis between the two ends of the bowel. Following this the hole in the mesentery created by removing the section of bowel is closed with sutures to prevent internal herniation. The resected section of bowel will then be removed from the abdomen and the abdomen closed. This concludes the procedure. [5] [6]
The right and left colon sit in the retroperitoneum. To access this space an incision is made along the line of Toldt. The colon is then mobilized from the retroperitoneum. Care is taken to avoid injury to the ureters and duodenum. The surgery then follows the same steps as small bowel resection. However, due to the colon's placement in the retroperitoneum, more dissection is often required to allow for tension free anastomosis. [5] [6]
Small bowel or colon cancer may require surgical resection. [7]
Small bowel cancer often presents late in the course due to non-specific symptoms and has poor survival rates. Risk factors for small bowel cancer include genetically inherited polyposis syndromes, age over sixty years, and history of Crohn's or Celiac disease. Cases that present before stage IV show survival benefit from surgical resection with clear margins. It is recommended that surgical resection also include lymph node sampling of a minimum of 12 nodes with some groups extolling more extensive resection. When evaluation determines cancer to be stage IV, surgical intervention is no longer curative, and is only used for symptom relief. [7]
Colon cancer is the third most common cancer and the second most common cause of cancer death in the USA. [8] Due to its prevalence, screening protocols have been created for prevention of disease. Screening colonoscopies with or without polypectomy have been shown to decrease cancer morbidity and mortality. [9] When cancer is more advanced and polypectomy is not possible surgical resection is necessary. Using imaging and pathologic evaluation of resected tissue the tumor may be staged using AJCC stages. [9] Surgical resection of tumors for staging and for curative purposes requires removal of local blood vessel and lymph nodes. Standard lymph node resection includes three consecutive levels of lymph nodes and is known as a D3 lymphadenectomy. [10] In addition to surgery adjuvant chemotherapy may be used to decrease risk of recurrence. Chemotherapy is standard with stage III cancer, case dependant in stage II and palliative in stage IV. [11] Diet high in processed food and sugary drinks has also been shown to increase recurrence of stage III colon cancer. [12]
Bowel obstructions are commonly secondary to adhesions, hernias, or cancer. Bowel obstruction can be an emergency requiring immediate surgery. Original testing and imaging include blood tests for electrolyte levels, and abdominal X-rays or CT scans. Treatment often begins with IV fluids to correct electrolyte imbalances. Obstructions may be complicated by ischemia or perforation of the bowel. These cases are surgical emergencies and often require bowel resection to remove the cause of obstruction. [13] Adhesions are a common causes of obstruction, and frequently resolve without surgery. [14]
Other causes of bowel obstruction include volvulus, strictures, inflammation and intussusception. This is not an exhaustive list.
Bowel perforation presents with abdominal pain, free air in the abdomen on standing X-ray, and sepsis. [15] [16] [17] Depending on the cause and size, perforations may be medically or surgically managed. Some common causes of perforation are cancer, diverticulitis, and peptic ulcer disease.
When caused by cancer, bowel perforation typically requires surgery, including resection of blood and lymph supply to the cancerous area when possible. When perforation is at the site of the tumor, the perforation may be contained in the tumor and self resolve without surgery. However, surgery may be required later for the malignancy itself. Perforation before the tumor usually requires immediate surgery due to release of fecal material into the abdomen and infection. [15]
Perforated diverticulitis often requires surgery due to risks of infection or recurrence. Recurrent diverticulitis may required resection even in the absence of perforation. Bowel resection or repair is typically initiated earlier in patients with signs of infection, the elderly, immunocompromised, and those with severe comorbidities. [16]
Peptic ulcer disease may cause perforation of the bowel but rarely requires bowel resection. Peptic ulcer disease is caused by stomach acid overwhelming the protection of mucus production. Risk factors include H. pylori infection, smoking, and NSAID use. The standard treatment is medical management, endoscopy followed by surgical omental patch repair. In rare cases where omental patch fails bowel resection may become necessary. [17]
Traumatic injuries, whether blunt force such as car accidents or penetrating wounds such as gunshot wounds, or stabbings, may also cause bowel perforation or ischemia requiring emergency surgery. Initial evaluation in trauma includes a FAST ultrasound exam followed by contrast CT abdomen in stable patients. The most common bowel injury in trauma is perforation and is repaired rather than resected if the injury involves less than half the bowel circumference and does not involve loss of blood supply. Resection is indicated with more extensive or ischemic injuries. [18]
Bowel ischemia is caused by decreased or absent blood flow through the Celiac, Superior Mesenteric, and Inferior Mesenteric arteries or any combination thereof. Untreated acute mesenteric ischemia can cause bowel necrosis in the affected area. This requires emergent surgery as survival without endovascular or operative intervention is around 50%. Ischemic bowel injury often requires multiple surgeries days apart to allow bowel recovery and increase odds of successful anastomosis. [19]
An anastomotic leak is a fault in the surgical connection between the two remaining sections of bowel after a resection is performed. This allows the bowel contents to leak into the abdomen. Anastomotic leaks may cause infection, abscess development, and organ failure if untreated. Surgical steps are taken to prevent leaks when possible. These include creating anastomoses with minimal tension on the connection and aligning the bowel to prevent twisting of the bowel at the anastomosis. However, it is believed that most leaks are caused by poor healing, not surgical technique. Risk factors for poor healing of anastomosis include obesity, diabetes mellitus, and smoking. [20] Treatment of the leak includes antibiotics, placement of a drain near the leak or developing abscess, stenting of the anastomosis, surgical repair, or creating of an ileostomy or colostomy. [21]
Any abdominal surgery may result in an incisional hernia where the abdomen was accessed. Hernias develop when the fascia of the abdominal cavity separates after the surgical closure. This may be due to suture failure, poor wound healing. Other risk factors include obesity and smoking. [22] Smaller closure stitches and the use of mesh when closing open surgeries may decrease the risk of hernia occurrence. However, the use of mesh is limited by the surgery performed and contamination or risk infection. [23]
When colon is resected hernias may form through the mesenteric defect. This is more common with gastric bypass surgery. Internal hernias may cause ischemia and require emergency surgery to resolve.
A common complication of all abdominal surgeries is adhesions. Adhesions are bands of scar tissue that form after surgery or injury to the abdomen. They can displace or obstruct areas of the bowel. Approximately 1 in 5 emergency surgeries are due to adhesive bowel obstruction. When possible this is managed without surgery with IV fluids, and NG tube to drain the stomach and intestines, and bowel rest (not eating) until the obstruction resolves. If signs of bowel ischemia or perforation are present then emergency surgery is required. Laparoscopic adhesiolysis is the most common surgery used when bowel rest and medical management fail to resolve the obstruction. [14]
When large amounts of small bowel are resected it can cause short bowel syndrome. Short bowel syndrome is a failure of absorption of nutrients due to resection of portions of the small bowel. It can be limited to a single nutrient or it can be total malabsorption. If the distal ileum is resected it commonly causes a mild form of short bowel syndrome with deficiency of only vitamin B12. When the entire small bowel is resected it can cause chronic complications. [24] [25]
The acute form lasts up to one month following bowel resection. Symptoms include diarrhea, malabsorption, and metabolic derangements. This is treated primarily by IV fluids and electrolyte replacement. Acute short bowel syndrome is followed by the adaptation phase which can last up to two years. During this time the small bowel slows movement of bowel contents to allow for more absorption. About half of all patients with short bowel syndrome progress to chronic disease. Chronic short bowel syndrome may require total parenteral nutrition and chronic central line use. These may cause complications such as bacteremia and sepsis. Other complications of short bowel syndrome are chronic diarrhea or high output from the ostomy site, intestinal failure associated liver disease, and electrolyte level abnormalities. [24]
Short bowel syndrome is rare and usually follows extensive ischemic bowel caused by internal hernias, volvulus, or mesenteric ischemia where the remaining small bowel is under 200 cm long. [24] [26]
Bowel obstruction, also known as intestinal obstruction, is a mechanical or functional obstruction of the intestines which prevents the normal movement of the products of digestion. Either the small bowel or large bowel may be affected. Signs and symptoms include abdominal pain, vomiting, bloating and not passing gas. Mechanical obstruction is the cause of about 5 to 15% of cases of severe abdominal pain of sudden onset requiring admission to hospital.
Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Since the abdomen contains most of the body's vital organs, it can be an indicator of a wide variety of diseases. Given that, approaching the examination of a person and planning of a differential diagnosis is extremely important.
Diverticulitis, also called colonic diverticulitis, is a gastrointestinal disease characterized by inflammation of abnormal pouches—diverticula—that can develop in the wall of the large intestine. Symptoms typically include lower abdominal pain of sudden onset, but the onset may also occur over a few days. There may also be nausea, diarrhea or constipation. Fever or blood in the stool suggests a complication. People may experience a single attack, repeated attacks, or ongoing "smouldering" diverticulitis.
A Meckel's diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the vitelline duct. It is the most common malformation of the gastrointestinal tract and is present in approximately 2% of the population, with males more frequently experiencing symptoms.
Short bowel syndrome is a rare malabsorption disorder caused by a lack of functional small intestine. The primary symptom is diarrhea, which can result in dehydration, malnutrition, and weight loss. Other symptoms may include bloating, heartburn, feeling tired, lactose intolerance, and foul-smelling stool. Complications can include anemia and kidney stones.
Colic in horses is defined as abdominal pain, but it is a clinical symptom rather than a diagnosis. The term colic can encompass all forms of gastrointestinal conditions which cause pain as well as other causes of abdominal pain not involving the gastrointestinal tract. What makes it tricky is that different causes can manifest with similar signs of distress in the animal. Recognizing and understanding these signs is pivotal, as timely action can spell the difference between a brief moment of discomfort and a life-threatening situation. The most common forms of colic are gastrointestinal in nature and are most often related to colonic disturbance. There are a variety of different causes of colic, some of which can prove fatal without surgical intervention. Colic surgery is usually an expensive procedure as it is major abdominal surgery, often with intensive aftercare. Among domesticated horses, colic is the leading cause of premature death. The incidence of colic in the general horse population has been estimated between 4 and 10 percent over the course of the average lifespan. Clinical signs of colic generally require treatment by a veterinarian. The conditions that cause colic can become life-threatening in a short period of time.
Intussusception is a medical condition in which a part of the intestine folds into the section immediately ahead of it. It typically involves the small intestine and less commonly the large intestine. Symptoms include abdominal pain which may come and go, vomiting, abdominal bloating, and bloody stool. It often results in a small bowel obstruction. Other complications may include peritonitis or bowel perforation.
A volvulus is when a loop of intestine twists around itself and the mesentery that supports it, resulting in a bowel obstruction. Symptoms include abdominal pain, abdominal bloating, vomiting, constipation, and bloody stool. Onset of symptoms may be rapid or more gradual. The mesentery may become so tightly twisted that blood flow to part of the intestine is cut off, resulting in ischemic bowel. In this situation there may be fever or significant pain when the abdomen is touched.
Colectomy is bowel resection of the large bowel. It consists of the surgical removal of any extent of the colon, usually segmental resection. In extreme cases where the entire large intestine is removed, it is called total colectomy, and proctocolectomy denotes that the rectum is included.
Gastrointestinal perforation, also known as gastrointestinal rupture, is a hole in the wall of the gastrointestinal tract. The gastrointestinal tract is composed of hollow digestive organs leading from the mouth to the anus. Symptoms of gastrointestinal perforation commonly include severe abdominal pain, nausea, and vomiting. Complications include a painful inflammation of the inner lining of the abdominal wall and sepsis.
Pneumoperitoneum is pneumatosis in the peritoneal cavity, a potential space within the abdominal cavity. The most common cause is a perforated abdominal organ, generally from a perforated peptic ulcer, although any part of the bowel may perforate from a benign ulcer, tumor or abdominal trauma. A perforated appendix seldom causes a pneumoperitoneum.
Ischemic colitis is a medical condition in which inflammation and injury of the large intestine result from inadequate blood supply (ischemia). Although uncommon in the general population, ischemic colitis occurs with greater frequency in the elderly, and is the most common form of bowel ischemia. Causes of the reduced blood flow can include changes in the systemic circulation or local factors such as constriction of blood vessels or a blood clot. In most cases, no specific cause can be identified.
An acute abdomen refers to a sudden, severe abdominal pain. It is in many cases a medical emergency, requiring urgent and specific diagnosis. Several causes need immediate surgical treatment.
A surgical anastomosis is a surgical technique used to make a new connection between two body structures that carry fluid, such as blood vessels or bowel. For example, an arterial anastomosis is used in vascular bypass and a colonic anastomosis is used to restore colonic continuity after the resection of colon cancer.
A proctosigmoidectomy, Hartmann's operation or Hartmann's procedure is the surgical resection of the rectosigmoid colon with closure of the anorectal stump and formation of an end colostomy. It was used to treat colon cancer or inflammation. Currently, its use is limited to emergency surgery when immediate anastomosis is not possible, or more rarely it is used palliatively in patients with colorectal tumours.
Bowel infarction or gangrenous bowel represents an irreversible injury to the intestine resulting from insufficient blood flow. It is considered a medical emergency because it can quickly result in life-threatening infection and death. Any cause of bowel ischemia, the earlier reversible form of injury, may ultimately lead to infarction if uncorrected. The causes of bowel ischemia or infarction include primary vascular causes and other causes of bowel obstruction.
Intestinal ischemia is a medical condition in which injury to the large or small intestine occurs due to not enough blood supply. It can come on suddenly, known as acute intestinal ischemia, or gradually, known as chronic intestinal ischemia. The acute form of the disease often presents with sudden severe abdominal pain and is associated with a high risk of death. The chronic form typically presents more gradually with abdominal pain after eating, unintentional weight loss, vomiting, and fear of eating.
Jejunostomy is the surgical creation of an opening (stoma) through the skin at the front of the abdomen and the wall of the jejunum. It can be performed either endoscopically, or with open surgery.
Internal hernias occur when there is protrusion of an internal organ into a retroperitoneal fossa or a foramen in the abdominal cavity. If a loop of bowel passes through the mesenteric defect, that loop is at risk for incarceration, strangulation, or for becoming the lead point of a small bowel obstruction. Internal hernias can also trap adipose tissue (fat) and nerves. Unlike more common forms of hernias, the trapped tissue protrudes inward, rather than outward.
Afferent loop syndrome is an uncommon side effect of gastric surgery. The afferent loop is made up of a segment of duodenum and/or proximal jejunum located upstream of a double-barrel gastrojejunostomy anastomosis. Abdominal pain and distension are signs of increased intraluminal pressure resulting from the accumulation of enteric secretions in the obstructed afferent loop.
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