NEWBORN SURGERY - 1976

2. SPECIAL SECTIONS

8. Malformations of Individual Organs and Systems

Small Intestinal Atresia.

We consider laparotomy via a transverse supraumbilical incision, following the clinic's standard technique, to be the method of choice.

Surgical Technique. Upon opening the Abdominal cavity, a blockade of the small bowel mesentery is performed using 0.25% novocaine solution (no more than 10 ml). After exploring the abdominal Organs and locating the atresia, the ends of the bowel are exteriorized into the surgical wound and surrounded with Sponges moistened with warm isotonic sodium chloride solution. The sequence of manipulations is crucial (Okmian, Rovamees, 1964; Spenser, 1968). Preparation of the bowel segments for anastomosis is mandatory. The aseptic stage of the operation is performed first on the distal segment, which in atresia has a small diameter, is spastic, and is filled with whitish plugs (shed intestinal mucosal Cells). Preparation of the efferent loop aims at its dilation and irrigation to clear it of mucus plugs (Grobvontobel, 1969). To this end, the end of the distal bowel segment is transected with scissors. A thin, blunt-tipped urethral catheter is inserted into the bowel lumen. An assistant holds the catheter in place with their fingers. The surgeon uses a 20 ml syringe to irrigate the bowel with warm isotonic sodium chloride solution. In high atresias, the bowel is irrigated until the fluid passes into the Large Intestine. In low atresias, the efferent bowel segment is irrigated until fluid begins to escape through the anus (the anal sphincter is stretched manually before surgery). Irrigating the bowel requires 100 — 200 ml of isotonic solution. This technique successfully stretches the bowel wall, increases its diameter, and clears the lumen of mucus plugs.

The next stage involves preparing the dilated, content-filled afferent segment for anastomosis. The wall of the afferent bowel segment has developed under pathological conditions; its muscular and nervous apparatuses are incapable of normal functioning, and peristaltic waves are ineffective. Functioning of the newly created anastomosis is possible only when it is constructed on a healthy, functionally adequate intestinal wall. This dictates the necessity of resecting 10 — 12 cm of the afferent segment along with its contents. The mesentery of the resected bowel segment is mobilized. Intestinal contents are gently "milked" into the efferent bowel segment. At the site of the intended resection, the bowel is clamped with two hemostatic clamps, resected, and removed.

The method of choice is an end-to-end small intestinal anastomosis. The discrepancy in diameters of the anastomosed segments is eliminated by incising the wall of the bowel on the antimesenteric side (Rickham, 1971), which allows for a secure anastomosis regardless of any difference in diameter. Intestinal clamps are not used during the creation of the anastomosis. If necessary, the assistant compresses the afferent bowel segment with their fingers to prevent leakage of intestinal contents. Most authors (Swenson, 1970; Zachary, 1971, et al.) prefer a single-layer intestinal suture when performing small bowel anastomoses in newborns. The advantages of the single-layer suture have been substantiated in experiments on growing animals (Herzog, 1973). We share this view and in recent years have used exclusively single-layer sutures in newborns. The availability of atraumatic needles and fine suture material (No. 0000, 00000) is mandatory. The thickness of a newborn's small bowel wall does not allow for engaging only the serosal and muscular layers; therefore, suture techniques that involve full-thickness penetration of the bowel wall are most applicable (Fig. 84). Among these, the suture recommended by Rickham is the simplest and most reliable. In this technique, the bowel is sutured with a single layer of full-thickness mattress sutures with knots tied on the inside. When constructing the anterior lip of the anastomosis, the needle is inserted 1.5 mm from the transected end of the bowel, the stitch length is 1.5 — 2 mm, and the distance between stitches is also 1.5 — 2 mm. Over-tightening of the sutures is unacceptable, as it leads to compromised Blood supply to the bowel wall followed by necrosis. There is no need to use a catheter with the proposed anastomotic technique.

Swenson proposes an original suture variation. Suture by his method is reliable, successfully approximates the bowel edges, and yields a good anastomosis. One may also use the Lembert suture. Approximation of the bowel wall with a conventional single-layer full-thickness suture with knots tied externally is possible, but less reliable. In cases of inadequate adaptation, leakage of intestinal contents may occur.

Class="center">Fig. 84. Variations of the single-layer invaginating intestinal suture.

a — mattress sutures with knots on the mucosa; b — mattress suture with knots on the outside; c — interrupted invaginating suture.

After suturing the bowel, the mesenteric defect is closed, and the operation is concluded. The abdominal wall is closed tightly in layers. To prevent postoperative obstruction in newborns, Sauer (1967) uses small bowel catheterization. A special catheter is inserted into the bowel lumen via a gastrostomy and brought out through the vermiform Appendix onto the anterior abdominal wall.

Proper preparation of the bowel segments, creation of an end-to-end anastomosis, and The Use of a single-layer suture improve Treatment outcomes. The anastomosis begins to function as early as the 2nd to 3rd day, allowing for a rapid transition to enteral Nutrition. These measures have helped reduce

the number of complications associated with suture failure or impaired anastomotic patency.

In membranous forms of atresia, techniques involving incision of the bowel wall, excision of the membrane, and subsequent transverse or angled closure of the bowel are preferred. In cases of atresia of the terminal ileum, construction of an end-to-side anastomosis (end of the Small Intestine to the side of the cecum or ascending colon) is indicated. The large intestine in such patients is incised along the tenia. A single-layer intestinal suture using one of the described techniques is advantageous.

Meconium ileus. In meconium ileus, the site of obstruction is typically located 6 — 12 cm from the ileocecal valve. At the site of obstruction, the meconium is thick and sticky; proximal to the obstruction, it becomes fluid. The bowel above the obstruction is dilated and filled with contents, peristalsis is impaired, and secondary trophic disorders up to perforation of the bowel wall are not uncommon. Restoration of intestinal patency in such cases is possible only surgically.

The literature describes cases of conservative management of meconium ileus using enemas with 76% Gastrografin (Wagget et al., 1970). The MECHANISM OF ACTION of the latter is based on its high osmotic activity (1900 mOsm/L), due to which fluid from the bloodstream (plasma is 300 mOsm/L) enters the bowel lumen. This softens the meconium and facilitates its evacuation. However, attempts to relieve the obstruction by conservative measures can be successful only when meconium plugs are localized in the large intestine (Sinerson et al., 1968).

The surgical technique depends on The amount of meconium and the degree of alteration of the bowel wall. In cases of small meconium accumulation, slight dilation of the afferent bowel segment, preserved peristalsis, and absence of bowel wall changes, an attempt is made to relieve the obstruction by washing out the meconium.

Surgical Technique. A purse-string suture is placed on the dilated part of the bowel proximal to the meconium accumulation, an enterotomy is performed, and a catheter is inserted into the bowel lumen. The intestinal contents are washed away with a freshly prepared 1 — 2% pancreatin solution or acetylcysteine. The bowel loops are carefully surrounded with sponges. Care must be taken to prevent the solutions from coming into contact with the bowel wall, as this leads to its dissolution. The meconium is gradually liquefied, removed from the bowel, and patency is restored; the distal, narrowed segment of the bowel is irrigated with isotonic sodium chloride solution until fluid begins to escape from the anus. The catheter is removed, and the opening in the bowel wall is closed with a double-layer purse-string suture.

In cases of massive meconium accumulation and secondary Changes in the bowel wall, resection of the altered segment is performed, followed by either an anastomosis using the method described above (Auburn, 1969) or exteriorization of the bowel ends. Enterostomy is resorted to in critically ill patients, as well as in the presence of Peritonitis when There is a risk of anastomotic breakdown (Fig. 85).

Fig. 85. Variations of decompressive enterostomies.

Proximal end brought out to the Skin, distal end closed (a). Mikulicz double-barreled enterostomy. Bowel segments are sutured with two rows of interrupted sutures, between which bowel walls are crushed during the Second Stage (b). Y-shaped enterostomy. The distal bowel segment is implanted into the side of the proximal one (c).

The Mikulicz enterostomy has gained the widest acceptance. After resection of the abnormal segment, the ends of the bowel are sutured together along their mesenteric border for a distance of 3 — 4 cm and brought out as a double-barreled enterostomy. In the postoperative period, the Contents of the afferent segment are collected in a plastic bag and infused into the efferent segment. This simple technique eliminates the loss of intestinal contents and achieves a rapid recovery of the child. When the stoma is no longer needed, it is closed after preliminary crushing of the spur with a special clamp. In recent years, the method of exteriorizing the proximal bowel segment with a closed distal stump and the Y-shaped enterostomy (Bishop, Koop, 1957) have become widespread. The end of the afferent bowel is implanted 2 — 3 cm from the bowel wall into the side of the efferent segment, the end of which is exteriorized and sutured to the skin. Peristaltic waves in the efferent bowel segment aspirate the contents of the afferent segment, significantly reducing the loss of intestinal contents. After restoration of transit and healing of the laparotomy wound, the exteriorized end of the bowel is closed extraperitoneally. From the first postoperative day, pancreatin (0.5 g 2 — 3 times a day) is administered into the patient's Stomach.

The prognosis for meconium ileus is serious. The condition is not limited to pancreatic damage and intestinal obstruction. The epithelium of the bronchial tree is affected, accompanied by pulmonary complications, which in most cases are the cause of death in such patients.

Intestinal obstruction caused by abnormal intestinal rotation. The cause of intestinal obstruction in malrotation is most commonly compression of the duodenum by an abnormally fixed cecum or by bands of an improperly formed cecal mesentery, midgut volvulus around the superior mesenteric artery, and Ladd's syndrome—a combination of the aforementioned pathological conditions.

Surgery for intestinal malrotation is performed on an emergency or elective basis, depending on the severity of the obstruction.

Surgical technique. The abdominal cavity is opened via a laparotomy approach According to the clinic's standard Procedure. A clear and systematic sequence during the exploration of the abdominal organs is essential. In malrotation, the causes of obstruction are most frequently localized in the region of the ROOT of the mesentery, the duodenum, and the ileocecal junction. Exploration begins with an inspection of the root of the mesentery. In malrotation, the bowel hangs from a narrow cord containing the mesenteric artery and vein. If volvulus is discovered, the bowel is untwisted. In most cases, the bowel twists in a clockwise direction. We operated on an infant in whom the bowel had wrapped around the root of the mesentery by 5 full turns. Following exploration of the root of the mesentery and reduction of the volvulus, the duodenum is examined, the peritoneal bands compressing the intestinal lumen are dissected, and any kinks are corrected. The next stage involves examining the ileocecal region and dividing adhesions that compress the bowel. The concluding phase of the operation is fundamentally important; to this day, surgeons have no consensus on this matter. In particular, the question of whether intestinal fixation is necessary after resolving the causes of obstruction, as well as the Methods of fixation, remains unresolved. Most authors leave the cecum in the upper right quadrant of the abdominal cavity (V. Toshovsky, 1957; G. A. Banrov, 1969). Some surgeons aim to relocate the cecum to the right half of the ABDOMINAL CAVITY AND fix it to the parietal Peritoneum (A. G. Pugachev, 1968; L. M. Kondratyeva, 1965; Saputo, 1959). These methods do not eliminate the possibility of recurrent volvulus and recurrence of obstruction.

In 1958, Bill and Grauman proposed an original method for intestinal fixation in cases of rotation anomalies. After eliminating the obstruction, the duodenum is fixed to the right parietal peritoneum with 2 to 3 sutures. The cecal dome is fixed to the sigmoid colon.

The advantages of this method lie in the ability, through simple maneuvers without opening the intestinal lumen or creating anastomoses, to reliably secure the cecum and prevent its fixation in its original abnormal position. However, the possibility of recurrent midgut volvulus is not entirely ruled out with this technique either. We have modified this method and supplemented it with mesenteric stabilization. Two fixation options are possible.

In cases where, following the relief of the obstruction and mobilization of the cecum, the latter can be successfully lowered into the right iliac fossa, it is fixed in the right lateral gutter to the parietal peritoneum with 2 to 3 sutures. The bowel mesentery is shortened using gathering sutures and fixed to the posterior abdominal wall (Fig. 86, a). This technique creates a Structure resembling the root of the small bowel mesentery and prevents the recurrence of volvulus.

Fig. 86. Diagram of intestinal fixation in malrotation.

When rotation is arrested during the final Stages of the second period, the cecum is fixed in the right iliac fossa, and gathering sutures are applied to the mesentery (a). If the ileocecal junction is unrotated, the cecal dome is fixed to the sigmoid colon, and plicating sutures are placed on the mesentery (b).

If it is impossible to lower the cecum into the right iliac fossa, its dome is fixed to the sigmoid colon at the Base of the mesentery using seromuscular sutures, and gathering sutures are applied to the mesentery.

The advantage of the proposed method of intestinal and mesenteric fixation is the reliable Prevention of recurrent obstruction and bowel volvulus. Using this method, 22 patients have been operated on with good outcomes. In cases where the bowel is fixed in the left half of the abdominal cavity, the appendix is removed.

Gastroenterostomy in newborns is impractical: it can be complicated by hemorrhagic gastrojejunitis. Two such cases were described by Stuart (1970).