Explain Ventricular Septal Defect in details ?

Indications of surgery :  Some VSDs close spontaneously or become smaller in size. This has to be taken into consideration before surgery is advised. Spontaneous closure can be complete by one year of age or the defect narrowed considerably. There is an inverse relationship between the probability of closure and age at which the patient is seen. SO per cent of patients with large VSD seen at one month of age ]nay close spontaneously. 60 percent of those seen at three months and 50 per cent seen at six months and 25 per cent of those presenting at 12 months.

A large VSD will have a diameter equal to aorta and a moderate one about 50 per cent a10 a small one less than one third of its diameter. When infants with large VSDs have severe and intractable heart failure or respiratory symptoms during the first three months prompt closure is advised. Most often these babies have other associated cardiac anomalies that are also correlated. Operation is not advised in the first three months, if the symptoms are not serious, as spontaneous closure may occur. In infants older than three months significant growth failure and increase in pulmonary vascular resistance are indications for surgery. An infants presenting st six months with severe symptoms and a pulmonary vascular- resistance index of 4- 8 Wood units/m2 needs early repair. 3n children having pulmonary resistance (Rp) less than 4 units/m2 surgery could be postponed up to one year. There is no advantage in waiting further as 11le results of surgery at one year is as good as at a later stage in experienced centers. 111 older children having large VSD with severe pulmonary particular disease, cardiac catheterization and calculations of shunt and pulmonary vascular resistance with isupmtercnol infusion and 100 per cent oxygen inhalation are done to decide operability. hloderate VSD with no elevation of pulmonary artery pressure may be advised surgery at 2-3 years of age. When smaller VSDs are seen at a later age, the consensus is to close surgically as there is possibility of endocarditis and prolapse of aortic cusp. There is also the social and psychological stigma of a harsh murmur creating problems at school check up, pre employment arid pre insurance medical examinations. Surgery carries negligible risk and there is complete cure.

Doubly committed or juxta aortic VSDs should be closed if there is any deformity of aortic cusp on echocardiography Surgery will prevent further prolapse of aortic cusp and increasing aortic regurgitation.
In complicated venhicular septa1 defects with PDA or coarctation, decision is taken based on the significance of each lesion.