Gastroschisis

Gastroschisis is a developmental defect of the anterior abdominal wall in which abdominal organs are eventrated through a defect in the anterior abdominal wall, usually located to the right of the normally formed umbilical cord.

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Epidemiology

Gastroschisis occurs with approximately equal frequency in boys and girls, with a slight predominance in the former, with a frequency of 3-4 per 10,000 live births. More than 70% of children are born prematurely and have prenatal hypotrophy.

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Causes gastroschisis

Until now, no factor has been identified that would definitely cause the development of gastroschisis. According to the hypothesis, premature involution of the right umbilical vein can lead to ischemia and (as a result) mesodermal to ectodermal defects, and disruption of the formation of the distal segment of the omphalomesenteric artery - to ischemia of the paraumbilical region on the right and, accordingly, to the occurrence of a paraumbilical defect. The ischemic process in the structures supplied by the superior mesenteric artery can be the cause not only of the development of a defect in the anterior abdominal wall, but also of the depletion of the blood supply by this vessel, as a result of which resorption of the intestinal wall with the formation of atresia is possible, which explains the combination of gastroschisis with malformations of the intestinal tube. Combinations of anomalies of other organs and systems and chromosomal anomalies are extremely rare in gastroschisis.

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Symptoms gastroschisis

Ultrasound of pregnant women allows to detect the developmental defect quite early - already in the 12-15th week of pregnancy. The intestinal loops located outside the abdominal cavity are determined. With early diagnosis of gastroschisis, the woman should be examined carefully and quite often in the future: in the second trimester of pregnancy, ultrasound is performed once a month, in the third trimester - weekly.

The manifestations of gastroschisis are obvious, and after the initial examination of the newborn, the diagnosis does not require any additional research methods. Eventrated are usually loops of the small and large intestine, the stomach, less often - the bottom of the bladder, in girls - the appendages and uterus, in boys in some cases - the testicles, if by the time of birth they do not descend into the scrotum. The liver is always in the abdominal cavity, formed incorrectly. Eventrated organs have a characteristic appearance: the stomach and intestine are dilated, atonic, the walls of the intestinal tube are infiltrated, the small and large intestines are located on a common mesentery, which has a narrow root - its width approximately corresponds to the diameter of the defect of the anterior abdominal wall - from 2 to 6 cm). All eventrated organs are covered with a layer.

The intestine in gastroschisis is somewhat shortened, its length is reduced by 10-25% compared to the norm. Amniotic fluid, being a chemical "compressor" for the serous membranes of the eventrated organs, causes their damage - the so-called chemical peritonitis. The color of the fibrin coating of the eventrated organs depends on the characteristics of the intrauterine environment: from dark red to yellow-greenish. It should be remembered that this fibrin clot, as a rule, hides absolutely viable organs. The protocol of the surgical examination of a newborn with gastroschisis includes echocardiography, neurosonography. To clarify the issue of mechanical patency of the intestinal tube in children with gastroschisis, it is necessary to perform high lavage of the eventrated colon before surgery - the presence of meconium in the colon indicates intestinal patency.

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Forms

Recently, the following working classification of gastroschisis has been adopted, allowing one to choose the optimal path for pregnancy and childbirth, as well as surgical correction of the defect.

• Simple form of gastroschisis.
• Complicated form of gastroschisis - with or without viscero-abdominal disproportion.

Patients with complicated forms usually require staged surgical treatment.

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Treatment gastroschisis

Pre-hospital stage

To prevent the child from cooling, the vented organs are immediately covered with a dry sterile cotton-gauze bandage after exposure, or the organs are placed in a sterile plastic bag and then covered with a cotton-gauze bandage. Body temperature is maintained by placing the newborn in an incubator with a temperature of 37 °C and humidity close to 100%. A permanent nasogastric or orogastric tube should be immediately inserted to prevent aspiration of gastric contents and for the purpose of decompression of the stomach. The tube should remain open during the entire transportation. Tracheal intubation should be performed only for individual indications.

A patient with gastroschisis is transported by a resuscitation doctor in a specialized resuscitation vehicle equipped with an incubator, breathing equipment, and equipment for monitoring the functions of vital organs. The child must be transferred to a surgical hospital as soon as possible after birth.

Hospital stage

Preoperative preparation

In a specialized hospital, the main tasks of preoperative preparation are maintaining the functions of vital organs, replenishing the volume of circulating blood, reducing hemoconcentration, correcting hemorrheal disorders, preventing hypothermia of the child, reducing the degree of viscero-abdominal disproportion by decompression of the gastrointestinal tract (gastric tube, high colon lavage).

Preoperative preparation depends on the degree of decompensation of the patient's condition, but usually takes 2-3 hours. It is considered effective if the child's body temperature has risen above 36 °C and laboratory parameters have improved (hematocrit has decreased, acidosis has been compensated).

Surgical treatment

Gastroschisis can only be treated surgically. Currently, surgical treatment methods for gastroschisis can be divided into three groups.

Primary radical plastic surgery of the anterior abdominal wall:

• traditional;
• anesthetic-free reduction of eventrated organs into the abdominal cavity (Bianchon procedure).

Delayed radical mastication of the anterior abdominal wall:

• siloplasty - plastic surgery of the anterior abdominal wall:
• alloplasty - the use of patches made of synthetic and biological materials.

Staged treatment for concomitant intestinal obstruction is enterocolectomy with closure of stomas and plastic surgery of the anterior abdominal wall.

The choice of treatment method depends on the degree of viscero-abdominal disproportion and the presence or absence of combined malformations of the intestinal tube.

Primary radical surgery is the most preferred method. It is performed on children who do not have pronounced viscero-abdominal disproportion. The therapy technique does not have any special features and consists of immersion of the eventrated organs into the abdominal cavity with subsequent layer-by-layer suturing of the surgical wound. It is recommended to leave the umbilical cord remnant due to deformation of the navel.

In 2002, the English surgeon A. Bianchi proposed a method for anesthetic-free reduction of the eventrated intestine, defined strict indications and proved its advantages.

Indications

Cases with an isolated form of gastroschisis without viscero-abdominal disproportion and with a good condition of the intestine (in the absence of a dense fibrin sheath) are subject to anesthesia-free reduction of the eventrated intestine:

Advantages

There is no need for artificial ventilation, anesthesia, large volumes of infusion therapy, the passage through the gastrointestinal tract is restored faster (independent stool - on the 4th-6th day), the number of bed-days is reduced, it is possible to get an excellent cosmetic result. The procedure is performed directly in the intensive care unit (in the conditions of a perinatal center or the intensive care unit of a surgical hospital).

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Technique of operation

Traction is performed on the umbilical cord remnant and the eventrated intestinal loops are immersed into the abdominal cavity without widening the defect of the anterior abdominal wall. Separate or intradermal sutures are applied to the edges of the defect.

In cases of severe visceroabdominal disproportion, methods are used to use a Teflon bag with a silastic coating as a temporary container for the part of the intestine that does not fit in the abdominal cavity, which is sutured or fixed to the fascial edge of the anterior abdominal wall defect. The bag is removed after 7-9 days, performing plastic surgery of the anterior abdominal wall. In addition, various patches of collagen-vicryl tissue, xenopericardial plates, and treated dura mater are used to treat gastroschisis with a high degree of visceroabdominal disproportion. Since these tissues cause violent proliferation of the child's own connective tissue, in most cases the abdominal wall defect closes without the formation of a ventral hernia.

Treatment of children with gastroschisis and combined anomalies of the intestinal tube presents significant difficulties. In case of intestinal atresia in a child with gastroschisis, it is recommended to impose a double entero- or colostomy at the level of atresia with subsequent closure (on the 28th-30th day).

In the postoperative period, treatment is carried out in several directions: maintaining the functions of vital organs and systems, restoring the functions of the gastrointestinal tract. The program of postoperative patient management includes the following activities.

• Resuscitation support (artificial ventilation, intensive care unit, antibacterial therapy, immunotherapy, total parenteral nutrition from the 4th day of the postoperative period).
• Decompression of the stomach and intestines.
• Stimulation of peristalsis.
• Initiation of enteral nutrition.
• Enzyme therapy and eubiotics.

Against the background of the therapy, the child usually begins to pass stool on his own on the 4th-6th day after the operation, and by the 12th-15th day, the passage through the gastrointestinal tract is completely restored, which allows enteral nutrition to begin and quickly bring it to a physiological volume.

Complications

Complications of the postoperative period can be divided into three groups:

• thrombosis of the mesenteric vessels, intestinal necrosis due to excessive increase in intra-abdominal pressure:
• adhesive intestinal obstruction against the background of unrecovered functions of the gastrointestinal tract:
• secondary infection, necrotic enterocolitis, sepsis.

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Forecast

The survival rate of children with gastroschisis in large neonatal surgery centers, where extensive experience in treating this pathology has been accumulated, approaches 100%. Children do not lag behind their peers in psychomotor development, study at school according to the general program or even according to a program with in-depth study of subjects, and participate in sports sections.

Thus, gastroschisis is an absolutely correctable defect, and rational restorative therapy leads in the overwhelming majority of cases to complete recovery and ensures a high quality of life.

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