"Cocoon" outside the intestine!

It is only for medical professionals to read and reference.
This image feature must be remembered
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 In daily life, to describe a person who is always nagging, we always say that the ears are all cocooned; we have walked a lot of roads, and the feet have a thick layer of cocoons
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In fact, not only the hands and feet and other parts will have calluses, but also the intestines
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In our daily work, some of the patients with intestinal obstruction encountered are related to cocooning outside the intestine
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Let's look at a case first: Case profile male, 31 years old, with intermittent abdominal pain and abdominal distension for more than 8 months
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The patient had no obvious cause for abdominal pain more than 8 months ago, accompanied by slight abdominal distension, no nausea, vomiting, no fever, no diarrhea, constipation, tenesmus, no stopping of gas or defecation
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It can be relieved after symptomatic infusion treatment is given by the local hospital
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Later, symptoms of abdominal pain and bloating recurred, and the symptoms were relieved after 1-2 days after cessation of exhaust.
Symptomatic conservative treatment was given to relieve the symptoms
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2020-10-29 Sudden left lower abdominal pain after dinner, showing persistent colic, accompanied by nausea and vomiting, no hematemesis, melena, and no fever
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The CT images of the patient are as follows: upper right (plain scan), upper left (arterial phase), lower right (portal phase), lower left (delayed period) upper right (plain scan), upper left (arterial phase), lower right (portal phase), Lower left (delayed period), right image (coronary position in the arterial phase), left image (coronary position in the portal phase), right image (coronary position in the arterial phase), and left image (coronary position in the portal phase).
, Gathered together to form a clumpy structure with clear boundaries, surrounded by an outer envelope-like structure of the intestine; the local intestinal wall of the jejunum is thickened, and the proximal lumen is slightly dilated
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The sigmoid colon is compressed and narrowed locally
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The patient was a young male with a chronic course of disease, mainly manifested as recurrent incomplete intestinal obstruction
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CT showed that the small intestine in the left middle and lower abdomen was folded tortuously, surrounded by a capsule-like structure
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This is the "abdominal cocoon" introduced to fellow physicians
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What is abdominal cocoon? Abdominal cocoon (AC) is a rare and unexplained peritoneal disease.
It manifests as part or all of the internal organs of the abdominal cavity are wrapped by a layer of dense white fibrous membrane.
Usually the contents of the wrapping are the most common in the small intestine, because it looks like a silkworm cocoon.
name, previous or idiopathic sclerosing peritonitis, congenital intestinal confined disease, psychosis intestinal cocoon-shaped package
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1.
The pathogenesis of abdominal cocoon is currently unclear
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Most scholars believe that abdominal cocoon is divided into primary and secondary according to the etiology
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The etiology of primary abdominal cocoon mainly includes: (1) Congenital dysplasia: Congenital diseases caused by the mutation of the peritoneum during embryonic development, including omental ischemia and uterine appendage hypoplasia or abnormality
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(2) Gender factor: Abdominal cocoon usually occurs in adolescent women, and most of them are accompanied by salpingitis or menstrual abnormalities.
It may be chemical peritonitis caused by retrograde infection of the genital tract or menstrual blood reflux, and then the capsule is formed
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(3) Regional factors: In some studies, the incidence of abdominal cocoon is high in tropical and subtropical cities.
The occurrence of abdominal cocoon may be related to regional factors
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The etiology of secondary abdominal cocoon includes: (1) Abdominal surgery history: patients with a history of abdominal surgery, including appendectomy, cholecystectomy, partial bowel resection, laparotomy, abdominal cavity chemotherapy, oophorectomy, portal cavity bypass surgery, hernia repair, such as stomach cancer and liver cancer resection
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(2) the abdomen-related diseases: including cirrhosis, heart failure with ascites, abdominal tumor, uremia, sarcoidosis, systemic lupus erythematosus, abdominal tuberculosis, pelvic inflammatory disease, foreign bodies, trauma
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2 Clinical manifestations of abdominal cocoon The clinical manifestations of patients with abdominal cocoon are often non-specific, and they often manifest as acute abdomen and intestinal obstruction symptoms: such as abdominal distension, vomiting, weight loss, loss of appetite, abdominal mass, and recurrent acute or subacute small intestinal obstruction, etc.
The length of the disease varies.
Some patients may have recurrent episodes and resolve spontaneously, and a few may be accompanied by ascites
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There are also patients who have no abnormal symptoms, but the disease is found during physical examination or treatment for other diseases
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For example, some patients were found to be infertile due to tubal adhesions, and the disease was discovered during treatment
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In patients with abdominal masses or recurrent incomplete intestinal obstruction, the possibility of abdominal cocoon should be suspected in the case of exclusion of abdominal neoplastic lesions
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3 Conventional X-rays and ultrasound in abdominal cocoon imaging are of little significance to the diagnosis of abdominal cocoon.
Except for some diseases)
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MSCT is the most effective way to detect abdominal cocoon
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The MSCT manifestations of abdominal cocoon include: (1) Extra-intestinal "capsule sign": refers to the cocoon-like, circular, or low-density fiber envelope around the small intestine of the cluster of lesions, which is called the "capsule sign
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"
(2) The small intestine presents a specific and fixed shape: the small intestine is limited or the entire small intestine gathers together, and the folds of the diseased intestine can be expressed as cauliflower, twisted, accordion, banana string, letter "U", and "pseudo-tumor sign".
Change, the shape is relatively fixed, and the position is mostly fixed
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(3) "Small intestine isolation sign": the small intestine is clearly separated from the surrounding normal loops, showing "isolation-like" changes, showing a translucent shadow, that is, the "small intestine isolation sign"
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(4) Small bowel obstruction: mostly incomplete small bowel obstruction
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The main symptoms are localized small intestine or segmental dilatation of the intestinal lumen and gas accumulation, with multiple gas-liquid levels and/or thick enhancement of the small intestine "intestinal fecal sign"
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(5) Other signs: including limited encapsulated effusion around the intestine, colon squeezing changes, thickening of the visceral peritoneum, adhesions and so on
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The following are typical images in the literature to deepen the understanding of the various signs of abdominal cocoon: (1) Extraintestinal "envelope sign": intestinal outsourcing membrane sign: coronal image (picture ①), small intestine fibrous membrane shows a "V" "The glyph wraps around; the axial position (Figure ②) shows more clearly, and the colon is compressed and moved
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(2) The small intestine presents a specific fixed shape + peri-intestinal encapsulated fluid: the intestine is slightly dilated and arranged like a banana, and a large amount of fluid can be seen between the intestine and the cocoon.
, Mild dilatation and effusion of the intestinal cavity with "intestinal fecal sign", localized effusion and complete "capsule sign" can be seen around the intestine, and "small intestine isolation sign" can be seen between the diseased small intestine and the surrounding intestinal loop
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4 Differential diagnosis of abdominal cocoon If the imaging signs of abdominal cocoon are grasped, the disease can be directly diagnosed without distinguishing it from other diseases
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However, abdominal cocoon is relatively rare in clinical practice, and intestinal obstruction is a common clinical disease
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It is difficult to directly diagnose the disease in clinical practice .

Abdominal cocoon is mainly differentiated from diseases that cause intestinal obstruction
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(1) Intra-abdominal hernia: Typical manifestations can be seen with hernia orifices, hernia sacs, and abnormal intestinal loops, which often cause closed-loop intestinal obstruction, and the mesenteric and blood vessels often gather locally and show a "cable sign"
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Generally, there is no extraintestinal and cocoon-like fiber envelope
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(2) Sclerosing peritonitis: It usually occurs in patients after long-term peritoneal dialysis or multiple intraperitoneal chemotherapy.
The abdominal wall is tight and the texture is tough as a plate.
CT can show thickening of the peritoneum and extensive adhesion with abdominal organs.
The signs of intestinal obstruction are relatively more obvious.
Light, no cocoon-like fiber envelope
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(3) Adhesive intestinal obstruction: Patients often have a history of surgery or abdominal tuberculosis, and clinical recurrent incomplete intestinal obstruction occurs
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CT often shows localized adhesions, bird's beak sign is often seen at the obstructive end, obstructed intestinal dilatation, fluid accumulation and gas accumulation, and the gas-liquid level often presents a "step-like" appearance
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There is no cocoon-like fiber envelope and "small intestine isolation sign" outside the intestine
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(4) Peritoneal encapsulation: It is a rare congenital abnormality, the peritoneal wrapping the small intestine forms an intra-abdominal hernia, the inner wall of the capsule is smooth, and there is no adhesion to the small intestine, the peristalsis of the bowel is generally unrestricted, and intestinal obstruction rarely occurs
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5 Treatment of abdominal cocoon The treatment of abdominal cocoon mainly includes surgery and conservative treatment.
There is no uniform standard for surgery or conservative treatment, and there is no relevant guideline
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The treatment method is often selected according to the patient's condition: that is, those with asymptomatic or mild symptoms may not be treated or conservative treatment, while patients with severe or frequent symptoms are still treated mainly by surgery
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The surgical method is mainly capsular resection or incision, and the choice of bowel resection is based on the presence or absence of disease in the bowel
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The main purpose of the operation is to fully release the adhesion, without the need to pursue complete resection and extensive separation of the capsule
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References: [1] Yang Xianchun, Chen Li, Wu Hanbin, Yang Keqin, Zuo Min.
MSCT diagnosis and differential diagnosis of abdominal cocoon[J].
Diagnostic Imaging and Interventional Radiology, 2018,27(02):117-122.
[2] Li Binbin, Yang Xiaohua, Wen Yanghui, Tang Zuxiong, Sun Ding, Qin Lei, Qian Haixin.
Clinical characteristics and experience in diagnosis and treatment of abdominal cocoon[J].
Chinese Journal of General Surgery, 2020, 35(06): 468-470 .
[3]Li Sheng, Liu Xianyang, Wen Bo, Yao Wei, Ma Kanggui, Tan Weize, Liu Senlin.
Experience in diagnosis and treatment of 26 cases of abdominal cocoon[J].
Chinese Journal of General Surgery,2020,35(04):300-303 .
[4],.
CT diagnosis and clinical manifestations analysis of abdominal cocoon[J].
Journal of Medical Imaging,2019,29(05):865-868.