Colonic volvulus

　　First, the etiology

　　The following conditions must be met for colonic volvulus to occur:

　　1, There is a longer movable colon.

　　2, The peritoneum corresponding to it is relatively longer.

　　3. The fixed points at both ends of the free intestinal loop must be very close.

　　4. There is a force suitable for colon volvulus.

　　Some patients with chronic constipation have a lot of intestinal content and gas, causing the intestinal loop to dilate. During pregnancy and the puerperium, the intestinal activity is enhanced and the position of abdominal organs changes. Congenital or acquired factors can lead to obstruction of the distal intestinal tract, abdominal surgery history, and other factors are common causes of colon volvulus. Other diseases that can cause this condition include intestinal ascaris ball, intestinal tumor, intestinal adhesion, Trypanosoma cruzi disease in South America, systemic sclerosis, intestinal gas cyst disease, etc. Sudden changes in posture or position can also cause colon volvulus, such as intense physical exercise such as basketball, which often causes the body to twist and swing significantly. However, this situation is rare. Volvulus of the cecum, ascending colon, or transverse colon is more common in young patients, some are due to overeating or onset after diarrhea, with an acute onset; while sigmoid colon volvulus is more common in elderly patients, with a longer history, and most have typical constipation history and recurrent attack history. Patients can describe the regularity and relief methods of their attacks relatively clearly; while young patients have a shorter history, prefer physical activity, and often relieve sigmoid colon volvulus without realizing it, often without clear history and onset pattern.

　　Second, Pathogenesis

　　The sigmoid colon has a large degree of freedom, and the fixed points at both ends of the intestinal loop are relatively close, so sigmoid colon volvulus is the most common. Sigmoid colon volvulus is mostly counterclockwise, with a few clockwise; sigmoid colon volvulus is more common in elderly male patients, while sigmoid colon volvulus in young people is more common in females; cecum volvulus is often congenital, with a long free intestinal loop of the cecum and ascending colon mesentery, which can twist when intestinal peristalsis is active or during intense physical activity, usually twisting clockwise around the mesentery, but occasionally counterclockwise as well; transverse colon volvulus is often related to surgical adhesions. The typical manifestations of sigmoid colon, transverse colon, and cecum volvulus are detailed in Figure 1. Colon volvulus of 180° to 360° is a non-banded intestinal obstruction; if it twists more than 360°, it can form a banded intestinal obstruction. Generally, colon volvulus below 360° does not easily affect intestinal blood supply and lumen patency, and obstruction often occurs when it is greater than 180°. After volvulus exceeding 360°, the mesenteric vessels are easily compressed, causing venous return obstruction of the twisted intestinal loop, leading to intestinal edema. There may be hemorrhagic effusion in the abdominal cavity, followed by impaired arterial blood flow leading to ischemia, even necrosis. The greater the degree of volvulus, the more opportunities there are for ischemia and necrosis. In addition, increased gas, fluid, and pressure in banded obstruction can also affect blood supply, so banded colon volvulus obstruction often easily leads to intestinal strangulation. Some patients may develop severe infection and shock due to intestinal necrosis, and it is necessary to pay special attention to the occurrence of mesenteric circulatory disorders, which can lead to intestinal necrosis and severe infection and shock in a short period of time.

　　Concurrent abdominal pain may be followed by abdominal distension, nausea, vomiting, and no排气 or defecation from the anus; the twisted intestinal loop causes an asymmetric abdominal appearance, and sometimes intestinal shape or peristaltic waves can be seen, with tenderness in the abdomen. In severe cases, the abdomen may show asymmetric bulging and irregular gaseous intestinal loops, and if not复位 promptly, the gaseous intestinal loop may cause intestinal wall necrosis, perforation, peritonitis, and even death due to intestinal obstruction.

　　1. Cecal volvulus is similar to small bowel obstruction, with an acute onset, mainly presenting with pain in the middle abdomen or lower right quadrant, sometimes palpable distension of the cecum in the lower right quadrant, with high-pitched bowel sounds and water-like sounds. When there is peritonitis, there is muscle tension and rebound pain, and bowel sounds disappear; when the pulse quickens, the body temperature rises, and signs of peritonitis appear, even with blood peritoneal effusion, it is a common manifestation of intestinal ischemia and necrosis, which can quickly lead to shock, and the chance of death will greatly increase.

　　The transverse colon volvulus is manifested as epigastric or upper abdominal pain, abdominal distension, some of which are similar to gastric dilatation.

　　2. The onset of sigmoid colon volvulus is diverse, it can be acute onset, and some patients present with subacute or chronic onset, most have a history of constipation, or recurrent intestinal volvulus obstruction, some can relieve spontaneously.

　　1. Prevention

　　If the colon volvulus is not caused by congenital developmental factors, then preventive measures should be taken against the pathogenic factors (such as elderly people with habitual constipation, intra-abdominal adhesions after surgery, eating high-fiber foods, antecubital movement after a full meal, etc.).

　　2. Prognosis

　　Timely treatment of colon volvulus usually has a good prognosis, but if there is intestinal strangulation, even rupture and perforation, the prognosis is poor. Delayed or improper treatment has a high mortality rate. If the non-surgical treatment of colon volvulus improves, further examination of the cause of the disease should be carried out, and if necessary, elective surgery can be performed to eliminate the cause to prevent recurrence.

　　1. Laboratory examination

　　If there are signs of peritoneal irritation and/or intestinal necrosis, an increase in blood leukocytes.

　　2. Imaging examination

　　1. X-ray manifestation

　　Generally, in the standing abdominal flat film, it can be seen that there is a large amount of gas-liquid level in the dilated intestinal tract, and in the supine abdominal flat film, the dilated colon can be observed, such as cecum volvulus, the small intestine can also be seen with gas expansion; but due to the presence of only one obstruction point in non-occlusive colon volvulus, it often shows the same symptoms as simple colon obstruction, and also shows the dilation of the colon above the obstruction. Therefore, it is generally difficult to distinguish in fluoroscopy or flat film. Only when performing barium enema examination to clarify the nature of colon obstruction, can the diagnosis be made. At this time, the twisted obstruction site can show a spiral-thin intestinal tract, or see twisted and crossed mucosa (along the longitudinal axis of the intestinal tract), or even see barium passing through the obstruction into the proximal intestinal tract. The typical X-ray manifestation of occlusive colon volvulus is that the twisted segment of the intestinal loop can be displayed as an expanded occlusive loop like an inflated oval balloon in the supine abdominal flat film, especially in sigmoid colon volvulus, the extremely dilated intestinal loops present a coffee bean-like shape, with double-line shadow of the intestinal wall visible in the middle. Due to the thinning of the intestinal wall, the two edges show dense white shadows in the shape of round nodules. The expanded lumen folds disappear. Barium enema examination of occlusive sigmoid colon volvulus will show a beak-like narrowing at the site of colon volvulus, and this sign will persist after multiple barium injections, and the barium cannot pass through this narrow place. The transverse colon volvulus expands into an oval shape in the upper and middle abdomen, with double-line shadow of the intestinal wall visible in the middle. The descending colon atrophy, cecum volvulus mostly occurs in a clockwise direction. In addition to the rounded expansion of the cecum, the small intestine is also significantly expanded.

　　2. CT

　　It is of great significance for the diagnosis of colon volvulus. Under CT, the cecum and small intestine in cecum volvulus can be seen to be dilated, and the mesenteric venous return is obstructed and dilated, forming a涡状turbulent pattern, known as the whirlpool sign; similarly, in the closed loop of the dilated sigmoid colon in sigmoid colon volvulus, there is also venous dilatation and whirlpool sign.

　　3. Low-pressure enema

　　It is also one of the auxiliary diagnostic methods, if 300 to 500 ml of saline cannot be infused, it indicates that obstruction may be present in the sigmoid colon.

　　4. Fiberoptic colonoscopy

　　Not only can it assist in diagnosis, but it is also a method of non-surgical treatment, but these methods all have limitations.

　　1. Natural herbs for protecting the gastrointestinal tract, peppermint is a good remedy for stomachache, and tea also contains a small amount of essential oil beneficial for defecation. The fruit精华 oil sold in pharmacies also has this effect.

　　2. Massage, massaging the abdomen with yiling oil clockwise can alleviate the pain of gastric pressure.

　　3. Some people cannot eat onions, some people cannot eat bread... The body may have adverse reactions to different foods, causing abdominal distension and pain. In response to this problem, there are three small tips: eat slowly and chew thoroughly during meals; chew a spoonful of chopped coriander after meals; use celery to make tea (add celery to hot water, remove after 20 minutes).

　　1. Non-surgical treatment

　　Sigmoid colon volvulus can often be treated with non-surgical methods, mainly suitable for the early stage of onset, while this method is contraindicated in the late stage of cecum volvulus and colon volvulus when intestinal necrosis is suspected. High-pressure saline enema and barium enema are methods of gradually increasing pressure during irrigation to dilate the narrowed intestinal tract during irrigation, relieve obstruction, and if gas and feces are discharged, abdominal distension disappears and abdominal pain is relieved, indicating that the volvulus has recovered. Fiberoptic colonoscopy decompression and repositioning is another effective non-surgical treatment method. The fiberoptic endoscope can enter the cavity directly and observe the position of the intestinal volvulus. If mucosal bleeding, ulcers, obvious inflammatory edema, or pus and blood flow above, continuing to enter the endoscope is prone to intestinal perforation; if the examination does not show the above intestinal wall necrosis, it can be slowly inserted through the obstruction into the volvulus intestinal loop, and a soft catheter can be placed into the volvulus intestinal loop through the colonoscope, a large amount of gas and loose stools can be discharged, the volvulus is often self-recovered, and symptoms improve. It should be noted that the entire process of insertion should be slow and gentle, entering the cavity, and should not be forced or blind inserted. The inserted soft catheter can be retained for 2 to 3 days. This can reduce recurrence in a short time, and also can observe the nature of the stool discharged, and judge whether there is intestinal necrosis.

　　Although the success rate of non-surgical treatment is as high as 76% to 92%, and the mortality rate and complications are lower than those of surgical treatment, the pathophysiological mechanism of torsion has not been solved, so the recurrence rate after treatment is as high as 57%. There is still controversy about the long-term results of non-surgical treatment. Some scholars advocate that after non-surgical treatment, it is necessary to actively prepare the whole body and intestines, and schedule surgical treatment to relieve the cause of torsion, unless the patient has contraindications to surgery.

　　Second, Surgical Treatment

　　In cases where non-surgical treatment fails or there may be intestinal necrosis, active surgical treatment should be adopted. Some patients may repeatedly experience sigmoid colon intussusception obstruction, and once diagnosed, immediate surgical treatment can be performed. During surgery, different surgical methods should be adopted according to the condition of the intestinal tract and abdominal cavity contamination.

　　1. If the blood supply of the intestinal tract is good after surgical reduction, the free intestinal loop can be fixed and sutured, such as sigmoid colon abdominal wall fixation, sigmoid colon mesentery fixation, sigmoid colon transverse colon fixation, sigmoid colon descending colon pleuroperitoneal extraperitoneal fixation, and cecum lateral abdominal wall fixation. These operations have few complications, simple operation, and can be decompressed through the rectum and anus before or during surgery, which can significantly reduce the recurrence rate.

　　2. When necrosis or perforation of the colon is found, and the abdominal cavity is severely contaminated, or the patient cannot tolerate long-term surgery, the necrotic intestinal segment can be resected and a proximal stoma can be created, with the distal end sealed and placed under the stoma incision, waiting for anastomosis in the second stage of surgery. This operation can reduce abdominal cavity infection caused by anastomotic fistula.

　　3. After resecting the necrotic intestinal segment during surgery, if the abdominal cavity is lightly contaminated and the intestinal edema is not severe, anastomosis can be performed in one stage, but the mortality rate will increase if an intestinal fistula occurs. Some scholars have performed intestinal resection and anastomosis without intestinal necrosis, considering the mortality rate to be low and without recurrence. Recently, some people have performed laparoscopic small incision sigmoid colon resection and anastomosis, which has less trauma, quick recovery, and no recurrence observed in follow-up.

　　During surgery, it is not necessary to reposition the necrotic intestinal segment before resection to avoid the entry of toxins and bacteria into the blood. Retrograde venous thrombosis can cause necrosis of the untwisted intestinal tract, and resection should be thorough. For megacolon with sigmoid colon intussusception, it is best to resect all the dilated colon, as the recurrence rate is high with the resection of the sigmoid colon alone.

　　Whether treated by non-surgical or surgical methods, intussusception should follow the treatment principles of intestinal obstruction, strengthen systemic supportive treatment, fasting, gastrointestinal decompression, anti-inflammatory and anti-shock therapy. Pay close attention, as the condition may change rapidly at times; surgery should be timely and preparations should be sufficient; attention should be paid to the occurrence of complications, and active treatment should be carried out.