A two-pound baby girl from Michigan, lovingly nicknamed "Mighty Girl" by her parents, underwent an open heart surgery to correct a blocked artery caused by a congenital defect.

Alexandra Mae Van Kirk was the smallest baby in the world to undergo this type of surgery. A week after the procedure her heart appears to be working and she is growing, the Grand Rapids Press reported.

Doctor Joseph Vettukattil performed the pulmonary balloon valvuloplasty, and has done 300 similar procedures over the course of his career. He said the smallest baby he had previously performed the operation on was four pounds.

When Heidi Van Kirk was 22 weeks pregnant she was told Alexandra was small for her stage of gestation. In follow-up checkups it was revealed the situation may be even more dangerous.

"They gave her [a] 35 percent chance of making it to a live birth," Heidi Van Kirk told the Grand Rapids Press.

The family was relieved when Alexandra came into the world with a full head of brown hair and a powerful scream.

The baby had a narrowed artery along with Hirschsprung's disease, which is characterized by missing nerve cells in the colon. She underwent an ostomy operation at 11 days old to help waste bypass her intestines. She may have surgery to remove part of her colon when she is older.

In most cases babies who undergo a pulmonary balloon valvuloplasty do not need  further treatment, Alexandra's family and doctors hope the same for her.

"She's cured. As far as her heart goes, she should be fine for the rest of her life," Vettukattil said.

Alexandra's parents are looking forward to the day she can come home and play with her 17-month-old sister Josephine.

"She has that opportunity, and that is what we are most grateful for," her father Matt said. "She's surpassed the doctors' expectations at every turn."