Rita P. Verma

By Rita Prasad Verma and Archana Kota

Necrotizing enterocolitis (NEC) is the commonest inflammatory gastrointestinal disorder of newborn infants, occurring primarily in premature neonates. Presenting as a medical and surgical emergency, it is associated with significant morbidity and mortality. NEC is characterized by acute intestinal inflammation and necrosis with intramural dissection of gas, pathognomically appearing as pneumatosis intestinalis on radiography. The incidence and mortality, with an inverse relationship to maturation, range between 3–11% and 17–20% respectively. Mortality may be up to 50% in extremely premature infants who require surgery for intestinal perforation or gangrene. The exact etiopathogenesis is unknown. Over 90% of infants are premature and more than 98% are enterally fed. NEC presents with feeding intolerance and abdominal distension, which may rapidly progress to cardiorespiratory decompensation and death in severe cases. Intestinal dysbiosis and its functional and immunological immaturity are proposed to play roles in the pathogenesis. While exact triggers are undetermined, the disease is marked by an anomalous immunological response of enterocytes to inflammation, invoking cytokines and chemokines. NEC is treated with bowel rest, antibiotics, cardiorespiratory support, parenteral nutrition, and blood products transfusion. Approximately 30% of cases require surgery and a significant number of survivors suffer from neurological deficits, intestinal dysfunction, and post surgical short bowel syndrome.

Part of the book: Pediatric Surgery, Flowcharts and Clinical Algorithms

By Rita Prasad Verma

Part of the book: Congenital Anomalies in Newborn Infants

By Rita Prasad Verma

Sirenomelia (SML) is a rare, almost universally fatal congenital malformation presenting pathognomically with fused lower extremities and absent or malformed perineum. The classic Sirenomelia sequence includes a uniform spectrum of caudal malformations, spinal defects, and a single umbilical artery. SML is postulated to be due to a genetic predisposition, unmasked by biochemical or environmental triggers. Primary developmental defects in the formation of caudal mesoderm or embryonic caudal vessels with resultant local tissue hypoperfusion are proposed hypotheses for its pathogenesis. SML occurs sporadically in humans, presumably due to a spontaneous mutation, and is speculated to have an autosomal dominant inheritance pattern. In mutant mice, specific defects in Cyp26a1 and Bmp 7 genes are demonstrated to produce offsprings with SML. Bmp 7 is a signaling protein, which belongs to the transforming growth factor-β (TGF β) superfamily. Tsg 1, a Bmp and chordin-binding protein, functions as an activator-inhibitor of Bmp signaling in the embryonic caudal region (ECR). Loss of Bmp7 genes combined with a complete loss or half-dose of Tsg 1 is demonstrated to produce an invariable SML phenotype. SML is also demonstrated to occur with increased Retinoic acid (RA) signaling in the ECR. The Cyp26a1 gene is involved in coding for an enzyme, which expresses in ECR and degrades RA. A specific defect in this gene leads to excess local RA concentration and SML generation with a reported 20% penetrance in mutant mice. However, the mutational screening of Cyp26a1 and Bmp 7genes has failed to confirm their involvement in mankind and the molecular defect and genetic inheritability of SML in humans remain undefined.

Part of the book: Congenital Anomalies in Newborn Infants

By Rita Prasad Verma

TGA is the commonest complex congenital cyanotic cardiac anomaly occurring during the first week of life. It is characterized by the unusual anomaly of ventriculoarterial discordance, with the aorta (A) originating from the right ventricle (RV) and the pulmonary artery (PA) from the left ventricle (LV). In the common Dextro form (DTGA), A is abnormally located to the right, anterior, and inferior of PA. The anatomic configuration results in the lethal hemodynamic pattern of 2 independent and parallel running circulatory circuits, which mandates creating a conduit to ensure the mixing of oxygenated and deoxygenated blood for survival. In the rare Levo form (LTGA), the aorta is placed anterior and to the left of PA with ventricular inversion. TGA is well tolerated in the fetus and is challenging to diagnose by fetal echocardiography unless the outflow tracts are specifically visualized. Postnatally the typical findings of murmur and cyanosis vary according to the associated cardiac defects and the degree of intercirculatory mixing. The arterial switch operation (ASO), which involves establishing ventriculoarterial concordance, is the standard surgical repair of D-TGA and has replaced the atrial switch procedures due to its superior long-term outcomes. The Rastelli procedure is used for complex DTGA cases. DTGA has a 90% mortality rate in the first year of life if untreated, while over 95% survive for 5 to 25 years after surgery. Post-surgical course may be complicated and require surgical revisions. The long-term outcome is associated with normal or mild to moderate neurodevelopmental disabilities, depending upon the type, complexity, and course of the disease. Expert follow-up of the patients into adulthood is an integral part of the management of TGA for best outcomes.

Part of the book: Congenital Anomalies in Newborn Infants