NEONATAL SURGERY - 1976

2. SPECIAL SECTIONS

8. Malformations of Individual Organs and Systems

Aplasia of the Anterior Abdominal Wall Muscles

Congenital aplasia of the anterior abdominal wall muscles is a rare anomaly resulting from impaired Development of the lateral processes of the primary vertebrae.

Clinical presentation. Diagnosis is straightforward. The abdomen is flaccid, wrinkled, and pendulous, with visible waves of intestinal peristalsis (Lattimer, 1958) (Fig. 67). Aplasia of the abdominal wall muscles is accompanied by Urinary Tract pathology in virtually all cases. Urological examination in such patients reveals a significantly distended Urinary Bladder, elongated tortuous Ureters, and Hydronephrosis. Male patients frequently present with bilateral cryptorchidism with intraabdominal Testes. Anomalies of the lower extremities are not uncommon: Clubfoot, congenital hip dislocation, etc. Patency of the urachus is identified in 50% of patients, cardiac malformations in 55%, and intestinal anomalies in 20%. The causes of Congenital absence of the anterior Abdominal muscles remain unknown. It is hypothesized that the primary defect involves the malformation of the nerve trunks of the anterior abdominal wall. Bladder dilation and Urinary System atony are attributed to the absence of normal intra-abdominal pressure.

Treatment. In cases where the triad of megacystis, megaureter, and hydronephrosis is detected, treatment begins with urinary tract decompression. Temporary cystostomy or nephrostomy is advisable. Benson (1962) considers the creation of bilateral ureterostomies to be the optimal emergency urological Procedure. Once renal function has recovered, the question of radical reconstructive surgery on the urinary tract can be addressed.

   Plasty of the anterior abdominal wall is performed after the function of the urinary system has been restored. Prior to this, wearing an abdominal binder is recommended to maintain intra-abdominal pressure and prevent the further progression of pathology in the Internal Organs. Several options for surgical correction of the defect exist. The anterior abdominal wall is closed by creating longitudinal folds. A midline incision is used during this procedure to avoid disrupting innervation and Blood supply. The formation of Skin folds, or "corrugation," is achieved using sutures placed on the inner surface of the abdominal wall, extraperitoneally whenever possible. Excess tissue is excised, and the edges of the approximated halves of the abdominal wall are sutured layer-by-layer along the midline. Another method for reinforcing the anterior abdominal wall is the creation of a tissue duplicature utilizing a cutis-sub-cutis technique. For this purpose, two arcuate incisions are made from the xiphoid process to the pubis. The epithelial layer on the skin surface outlined by these incisions is meticulously removed using a dermatome or a sharp scalpel (razor blade). The success of the surgery largely depends on the quality of skin surface preparation. The lateral flaps are mobilized to the anterior axillary lines and sutured over the central flap. Postoperative care requires wearing an abdominal binder.

Class="center">Newborn with a giant omphalocele containing The Liver and intestines (left). Newborn with ectopia cordis combined with a defect of the upper abdominal wall (right).

Genital hiatus of a newborn female suffering from hydrocolpos. Protrusion of the membrane obstructing the vaginal introitus (left). Gross specimen. Urinary tract of a newborn with multiple malformations: polycystic Horseshoe Kidney, obliterated distal right Ureter, and left-sided megaureter (right).

Newborn with a complicated form of spinal hernia—ruptured membranes and pelvic organ paralysis (left). Uterine and vaginal prolapse in a newborn with the paralytic form of spinal hernia (right).

Photothoracoscopy of a newborn. In the field of view: a large mediastinal tumor (right) encapsulated with a well-developed vascular network (left). Calcinosis of the perirectal tissue, subcutaneous tissue, and right buttock with rectal prolapse (right).

If Muscle fibers are present within the thickness of the anterior abdominal wall, they should be strengthened whenever possible through continuous massage and physical therapy.

Congenital absence of the abdominal muscles must be differentiated from diastasis of the rectus abdominis muscles. In this condition, the rectus muscles are spaced wider apart than usual, and the tendinous intersection between them lacks muscular elements. When crying or straining, such infants exhibit a distinct protrusion of the abdominal wall. Rectus diastasis is not accompanied by internal organ pathology, and plastic surgery is performed solely for cosmetic purposes at an older age.

Embryonic umbilical cord hernia

Embryonic umbilical cord hernia (omphalocele) is a severe Congenital malformation of the anterior abdominal wall in which viscera herniate through a defect in the umbilical region, separating the Tissues of the proximal umbilical cord. Muscles and skin overlying the tumor are absent; the abdominal organs are covered by a thin transparent or translucent membrane continuous with the umbilical cord.

Embryonic umbilical cord hernia is a relatively rare anomaly, occurring on average once every 5,000 to 6,000 births (M. S. Simanovich, 1958; Sander, 1959).

The Embryogenesis OF THE umbilical region and The Development of embryonic umbilical cord hernia are schematically illustrated in the figure.

Clinical presentation. Diagnosis is uncomplicated. The infant is born with an umbilical tumor ranging in size from a plum to a newborn's HEAD or larger, covered with a smooth, glossy, translucent or transparent whitish membrane through which the underlying abdominal organs are visible. The defect in the anterior abdominal wall can reach 12 cm or more in diameter and is not always proportional to the size of the hernia sac. At the junction of the skin and the membranes of the hernia sac, a sharply demarcated edge forms, which in a significant number of cases is bright red due to interrupted dermal capillaries here. Healthy skin may extend onto the stalk of the hernia sac by 2 — 5 cm. During delivery, the membranes of the herniated sac may rupture, leading to Evisceration of the abdominal organs. The prolapsed organs rapidly become infected, Peritonitis develops, and the prognosis becomes guarded.

Depending on the timing of the malformation's onset, Three types of hernias are distinguished: true embryonic hernias, fetal or umbilical cord hernias, and mixed forms. If the arrest of intestinal and anterior abdominal wall development occurs prior to the 3rd month of intrauterine life, a true embryonic hernia develops. In such patients, the membranes of the hernia sac are typically densely adherent to the liver, since the mesoblast from which Glisson's capsule of the liver forms has not yet developed by this time, and the primitive membrane is fused directly with the liver parenchyma. Awareness of this fact is practically important, as any attempt to excise such membranes during surgery is accompanied by rupture of the hepatic parenchyma and massive Hemorrhage, which is extremely difficult to stop. Fetal hernia forms at a later stage. In this form, a free peritoneal cavity exists beneath the membranes, the hernia sac is internally lined with Peritoneum, and adhesions between the membranes and the liver are absent.

It is important for the practicing physician to be familiar with the Classification that divides hernias into three groups based on the dimensions of the hernia protrusion and the anterior abdominal wall defect: 1) small hernias (protrusion size up to 5 cm, anterior abdominal wall defect diameter up to 3 — 4 cm); 2) medium-sized hernias (protrusion size up to 10 cm and anterior abdominal wall defect diameter up to 7 cm); 3) large hernias (protrusion size greater than 10 cm and anterior abdominal wall defect diameter greater than 7 cm).

Using the classification presented, the surgeon is able to determine the indications for various treatment Methods, the proper Selection of which largely dictates the treatment outcomes.

In embryonic umbilical cord hernias (omphaloceles), the Contents of the hernia sac may include virtually all abdominal organs, and in cases of associated diaphragmatic defects, even The Heart and Lungs. Most frequently, the hernia contents consist of the intestines and liver.

Differential diagnosis. Diagnostic errors are practically possible only with small hernias, when little significance is attached to a slight thickening at the Base of the umbilical cord, and during its ligation or application of the Rogovin clip, the contents of the hernia sac are clamped, causing intestinal obstruction or the formation of intestinal fistulas. The following case observation serves as an example.

Boy Ts. was admitted to the neonatal surgery department on June 11, 1966, 6 hours after birth, presenting with symptoms of intestinal obstruction. The Anamnesis revealed that at birth there was a slight thickening at the base of the umbilical cord, which had been ligated and severed. Upon surgical exploration, it was found that along with the base of the umbilical cord, the child's ileocecal junction had also been severed. An intestinal anastomosis was performed. Recovery.

The child had a small embryonic umbilical cord hernia with herniation of the ileocecal junction from the Abdominal cavity, which was severed during the ligation of the umbilical cord. To avoid such errors, it is essential to carefully inspect the base of the umbilical cord prior to its ligation. In cases where the proximal part of the cord is thickened, a ligature should be placed above the thickened area and a surgical consultation should be requested for the infant.

Malformations of the anterior abdominal wall such as gastroschisis or enteroschisis may be of differential diagnostic interest. In these cases, the cause of the malformation is the underdevelopment of the lateral processes of the primary vertebrae that form the supraumbilical segments of the anterior abdominal wall. The child is born with an abdominal wall defect through which the abdominal organs eviscerate. Unlike embryonic umbilical cord hernias, in gastroschisis and enteroschisis the abdominal wall defect is not associated with the umbilical ring, and the organs eviscerating through it are not covered by any tissues (Prillewitz, 1968; Voleton, 1972).

Treatment. There are two methods for treating embryonic umbilical cord hernias: surgical and conservative. Proponents of the surgical method argue that the absence of Blood Vessels in the membranes covering the hernia protrusion rapidly leads to their necrosis and infection of the abdominal cavity, and they recommend performing surgery in all cases During the first hours of the child's life, while the intestine is still empty and the membranes are uninfected. In recent years, due to the possibility of preventing peritonitis using modern Antibiotics and antiseptics, considerable attention has been given to the conservative method, in which recovery occurs after the hernia sac membranes are replaced by granulation tissue proliferating from the wound edges, followed by its epithelialization. The choice of method is of paramount importance; the correct resolution of this issue largely determines the treatment outcomes.

Fig. 68. Embryogenesis of the umbilical region and anterior abdominal wall. Embryonic umbilical cord hernia.

The Pathogenesis of embryonic umbilical cord hernia is primarily driven by two factors: impaired intestinal rotation during The First stage of rotation and underdevelopment of the anterior abdominal wall.

Impaired intestinal rotation manifests as the persistence of the temporary "physiological" umbilical hernia, which forms in 5-week embryos due to a mismatch in the growth rates of the intestine and the abdominal cavity, and spontaneously resolves by the 11th week of embryonic development (d).

The Muscles of the lateral and ventral abdominal walls originate from the lower thoracic and upper lumbar myotomes (a), which grow in a ventral direction (b) and fuse together. The primary Differentiation of the muscles occurs concurrently with The process of bowel reduction into the developing embryonic abdominal cavity (c). Thus, underdevelopment of the anterior abdominal wall muscles becomes an integral element in the pathogenesis of congenital embryonic umbilical cord hernia.

In difficult-to-diagnose small hernias, applying a clamp to the umbilical cord can lead to crushing of the intestinal loop located in the initial PARTS OF THE umbilical cord, resulting in obstruction, intestinal fistula, or peritonitis (e).

In our clinic, indications for various treatment methods have been developed. 1. For small-sized hernias, radical surgery is indicated within the first hours of the child's life, when the hernia sac membranes are uninfected, the intestine is empty, and the abdominal wall can be easily closed tightly. 2. For medium-sized hernias not complicated by severe associated malformations, an extraperitoneal surgical method is indicated with complete or partial closure of the defect edges, depending on the child's condition and the dimensions of the abdominal cavity. 3. Large hernias without severe associated malformations are operated on using the two-stage Sivak–Gross method. 4. In the presence of associated malformations such as a patent vitelline duct, intestinal obstruction, etc., regardless of the size of the hernia protrusion, the hernia sac membranes are excised, the abdominal cavity organs are explored, the malformation is corrected, and the anterior abdominal wall defect is closed without tension. At the same time, one should not always strive to approximate the aponeurotic edges of the defect, as this may increase intra-abdominal pressure and lead to the infant's death. It is often sufficient to suture the edges of the skin, undermined laterally, over the defect. 5. When the child is admitted late, when the hernia sac membranes are infected, as well as in cases where medium and large hernias are complicated by severe associated malformations, the conservative treatment method is indicated.

   Surgical treatment. Preoperative preparation is carried out according to general guidelines.

   Maintaining spontaneous breathing is mandatory during anesthesia administration. Failure to comply with this condition during abdominal wall plastic repair may exceed the achieved threshold of intra-abdominal pressure, resulting in the inability to restore spontaneous breathing postoperatively.

Surgical technique. The umbilical stump beneath the clamp or tape is ligated with a strong ligature, severed, and treated with iodine tincture. A circumscribing incision is made 1–2 mm from the edge of the defect. The skin is incised through its entire thickness down to the subcutaneous tissue. Its edges are undermined, the hernia sac membranes are excised, and the umbilical vessels are ligated. The eviscerated organs are reduced into the abdominal cavity, and the defect edges are closed tightly in layers.

For medium-sized hernias, the surgeon's tactics depend on the results of trial reduction. The child is prepared for surgery according to general guidelines. General anesthesia is used, with spontaneous breathing. After treating the hernia sac membranes with 70% alcohol and 1% iodine tincture, the surgeon, with sterile hands, cautiously attempts to reduce the contents of the hernia sac, guided by the child's Respiration. If the abdominal cavity is of adequate size, it is possible to reduce the eviscerated organs and approximate the defect edges with the fingers without compromising respiration. In such patients, a single-stage radical operation is performed with excision of the hernia membranes and repair of the abdominal wall defect.

In cases of abdominal cavity underdevelopment, reducing a portion of the organs significantly increases intra-abdominal pressure, disrupts the respiratory rhythm, or causes the child to stop breathing. In such patients, a two-stage extraperitoneal operation is indicated.

Following repeated Treatment of the hernia membranes and surrounding skin with alcohol and iodine, a circumscribing incision is made 1–2 mm from the transition site of the hernia sac membranes into healthy skin. The abdominal cavity is not opened. The skin along with the subcutaneous tissue is bluntly undermined laterally by 3–6 cm. A portion of the hernia sac membranes is sutured with catgut ligatures and removed without opening the abdominal cavity. Then, the contents of the hernia sac are partially reduced into the abdominal cavity (avoiding respiratory compromise). The skin edges over the membranes are approximated and sutured with U-shaped nylon stitches.

For large hernias, a two-stage method is employed (Gross, 1948, 1958). Trial reduction is not performed in such patients.

Following thorough treatment of the hernia sac membranes with alcohol and iodine, the base of the umbilical cord is transfixed with a catgut ligature and severed. A circumscribing incision of the skin and subcutaneous tissue is made at the base of the hernia sac. The abdominal cavity is not opened. The skin with subcutaneous tissue is widely undermined laterally—from the chest to the pubic area, from the iliac crests to the axillary regions—and sutured over the hernia protrusion. The Second Stage of the operation—repair of the ventral hernia—is performed at the age of 1 to 3–4 years, when the abdominal cavity becomes capable of accommodating the eviscerated organs.

In very large hernias, when the membranes cannot be closed even with skin widely undermined from the edges, Schuster (1967) proposes a multi-stage surgical method involving the gradual reduction of the hernia contents using a silastic pouch. According to the author's data, this method allows the cure of the largest hernias in 2–3 stages.

In recent years, interest in the conservative treatment of embryonic umbilical cord hernias has grown. When a child is admitted late, when the membranes are already infected and burying them beneath the skin is impossible, the conservative treatment method remains the method of choice (V. D. Tikhomirova, 1959; Soave, 1961; Glantz et al., 1968; Joppich, 1969).

Treatment is initiated immediately after the child's birth. The local application of tanning agents and antiseptics has become the most widespread approach. The simultaneous use of general supportive therapy and antibiotics is mandatory. As clinical experience has shown, the best substances for local application are a 2% aqueous solution of merbromin and a 1% iodine tincture.

The infant is placed under a radiant warmer or in an incubator. The umbilical cord stump is ligated at the base with a sturdy silk ligature and severed. The membranes of the hernia sac are painted with 70% alcohol and 1% iodine tincture. Once the membranes dry, they are treated with alcohol and iodine once more. This procedure is repeated 3 to 4 more times with 5 to 10-minute intervals. Care must be taken during application to prevent the iodine tincture from spilling onto the surrounding healthy skin, as this may cause chemical Burns.

Next, the membranes are left uncovered and, during the first 1 to 2 days, are treated every 1 to 1.5 hours. As a result, the membranes of the hernia sac become impregnated with iodine and dry out, forming a dense, elastic crust that is impermeable to microorganisms. Once the crust has formed, a mildly compressive aseptic dressing is applied to the herniation. The treatment of the membranes with alcohol and iodine is continued during dressing changes. Simultaneously, the infant is prescribed antibiotics, blood and plasma transfusions, intravenous fluids as indicated, and Vitamins. Granulations proliferate beneath the crust from the edges of the healthy skin, and wound epithelialization takes place. The membranes slough off 3 to 5 weeks after THE START OF treatment. Subsequently, the wound epithelializes within 1.5 to 5 months from the beginning of therapy, and the child recovers (Fig. 69).

Fig. 69. Stages of epithelialization of the anterior abdominal wall defect during conservative management of an infected omphalocele (congenital umbilical hernia). Appearance of the infant upon admission (a), 20 days later (b), and 1.5 months after the start of treatment (c).

Proper and timely management ensures the successful cure of virtually all infants with small and medium-sized hernias. In cases of large hernias and severe concomitant malformations, favorable outcomes are observed in only 50 to 60% of cases (V. Tošovský, 1957; V. V. Gavryushov, 1962; Pohl, Schmierer, 1966, et al.).

Following the first stage of a two-stage operation or when utilizing conservative treatment, the infant is discharged from the clinic with a large ventral hernia (Fig. 70), which can only be corrected surgically. Long-term follow-up studies of omphalocele treatments demonstrate that subsequent ventral hernias may develop not only after the aforementioned techniques, but even following radical operations in the area of the postoperative scar. Large ventral hernias result in a cosmetic defect and restrict the child's mobility, while also impairing the GROWTH AND DEVELOPMENT of abdominal organs. Prompt repair of such a hernia is an essential prerequisite for the child's normal development. Surgery is performed when the abdominal cavity becomes capable of accommodating the contents of the hernia sac. In some cases (when the abdominal cavity is well-developed), this becomes feasible at 10 to 11 months of age; in others, at 2 to 3 or 5 years of age. Regular massage and daily trial reductions of the prolapsed organs contribute to the development of the muscles of the anterior abdominal wall and the abdominal cavity.

Fig. 70. Newborn with a ventral hernia following Gross's procedure for an omphalocele (a). Infant after conservative management of an omphalocele (b).

Vitelline Duct Anomalies

Depending on the degree of arrested regression of the vitelline duct, an infant may be born with various malformations (Fig. 66). If the vitelline duct remains patent throughout its entire length, a complete umbilical fistula occurs.

The Clinical presentation of this malformation is typical, and diagnosis is straightforward. The duct connects the umbilical region to the terminal ileum (see Fig. 66). After the umbilical cord drops off, liquid intestinal contents and gas begin to discharge from the umbilical ring. Sometimes, a red mucosal fringe is clearly visible along the edge of the umbilical ring. The continuous leakage of intestinal contents leads to rapid maceration of the surrounding skin, accompanied by inflammatory signs. The infant loses significant amounts of intestinal contents and rapidly wastes away. In cases of wide fistulas, evagination with impaired intestinal motility is possible. In doubtful cases, fistulography is performed, whereby the contrast medium enters the Small Intestine through the fistula.

Surgical treatment is indicated. The operation is performed once the diagnosis is established. Under general anesthesia, the fistula is temporarily packed with a fine gauze strip and sutured to prevent wound contamination. The fistula is then excised using a circumferential incision. The intestinal defect is closed with a single-layer suture. The postoperative period is managed according to standard protocols. The prognosis is generally favorable.

When the regression of the vitelline duct is impaired on the abdominal wall side, the infant is born with an incomplete umbilical fistula. The clinical picture of this anomaly is caused by a depression in the umbilical fossa, from which mucous fluid constantly oozes. Discharge from the umbilical depression is characteristic (the end of the duct is lined with epithelium identical to that of the intestine, which continuously secretes fluid). Upon examination of the umbilical fossa, a fistular opening is found at its base, discharging serous or serosanguineous fluid. Secondary inflammatory signs are typically present. The diagnosis is refined by probing the fistula, which leads toward the abdominal cavity. Prolonged umbilical weeping caused by an umbilical granuloma (fungus) should be ruled out. In cases of a granuloma, no fistulous tract is present, and a detailed examination of the umbilical wound reveals the base of the granulation tissue mass.

Differential diagnosis from an incomplete urachal fistula is sometimes difficult. The latter is characterized by the direction of the fistulous tract toward the urinary bladder and the acidic reaction of the fistula discharge.

Treatment. Conservative management is indicated for incomplete umbilical fistulas in newborns. The wound is kept clean and regularly irrigated with hydrogen peroxide solution, followed by cauterization of the fistula walls with 5% iodine tincture, 10% silver nitrate solution, etc. If conservative treatment proves ineffective, surgery is indicated at 6 months of age.

In cases of impaired regression of the intraperitoneal portion of the vitelline duct, a vitelline duct cyst (enterocystoma) or a Meckel's diverticulum may develop. Sometimes, a fibrous cord remains in place of the duct. These anomalies in newborns are generally asymptomatic. Cysts and fibrous cords in the region of the duct can cause volvulus or intestinal intussusception, leading to acute intestinal obstruction. The diagnosis is made intraoperatively. Rare cases of diverticulitis are usually misdiagnosed as acute appendicitis prior to surgery.

Urachal Anomalies (Disorders of Urachal Regression)

Impaired regression of the urachus can lead to the formation of malformations identical to those of the vitelline duct (Fig. 66).

In a complete urachal fistula, the dome of the urinary bladder is connected to the umbilical region by a patent duct. After the umbilical cord detaches, urine begins to leak from the umbilical fossa. Upon applying pressure to the urinary bladder or during urination, urine emerges in a jet stream. The diagnosis is confirmed by probing. The urachus courses downward toward the bladder. In doubtful cases, a methylene blue dye test is utilized.

Surgical treatment is indicated. The presence of a patent urachus carries the risk of urinary tract infection and urosepsis; therefore, surgery is performed immediately upon establishing the diagnosis. Excision of the fistula is the procedure of choice. The prognosis (immediate and long-term) is generally favorable.

In an incomplete urachal fistula, the clinical presentation is identical to that of an incomplete vitelline duct fistula. In some patients, the diagnosis is confirmed by probing the fistulous tract. The discharge from the fistula in these cases is acidic in nature. Newborns receive conservative management, similar to that for a vitelline duct fistula. Rare cases of bladder diverticula and urachal cysts in newborns are generally undiagnosed.