Doctors at a major hospital in Beijing completed on Tuesday a thorny surgery on a patient suffering chronic pulmonary hypertension, marking the 50th surgery of its kind completed in the hospital.

The patient, a 67-year-old male, exhibited symptoms of the syndrome, including heart failure, when admitted to China-Japan Friendship Hospital last week, Zhen Yanan, a surgeon that participated in the operation, said.

Zhen and his colleagues worked for nine hours to finish the surgery, successfully removing the thrombi, or blood clots, that were intricately stuck on the inner membranes of the patient's lung arteries, which caused pulmonary hypertension, he said.

The surgery, called pulmonary thromboendarterectomy, or PTE, is the only effective method to cure patients with such diseases, but it is highly risky and demanding, Zhen said, adding only a few hospitals in China have ever completed such surgeries.

The patient is under intensive care in the hospital and is expected to recover his health soon, he said.

"Pulmonary hypertension is a common disease and can result in serious consequences, including death, if not properly treated," Zhen said. "But the disease is often misdiagnosed or left undiagnosed in many places. Even many doctors lack adequate knowledge of the disease."

As a leading hospital in the diagnosis and treatment of chronic pulmonary hypertension in China, China-Japan Friendship Hospital plans to formulate standards on the diagnosis and surgical treatment of the disease that suits China’s conditions, so more patients with the disease can benefit with the promotion of the standards, Zhen said.