When Mr. Ruzzamenti told his wife, My Nhanh, about his plans, she made it abundantly clear, despite her rudimentary English, that she would leave him and return to Vietnam if he followed through. She had immigrated only eight months before, after a marriage largely arranged by the Buddhist temple where Mr. Ruzzamenti volunteered as a groundskeeper. If he died on the table, she demanded, how would she get by in a country where she felt so out of place?

“I wanted to scare him,” Ms. Ruzzamenti, who is known as Lucy, said as she combed her husband’s close-cropped hair with her fingers. “And to tell him that it scares me.”

Mr. Ruzzamenti was impressed by his petite wife’s ferocity — “She’s a bully,” he said — but he disregarded her threat. He knew research showed that the risk of death from kidney retrieval surgery was 3 in 10,000 and that people with one kidney live as long as those with two. To him, there was little doubt that any good he created would far outweigh any temporary discomfort to him or his wife.

As it happened, Mr. Ruzzamenti experienced an unusual level of pain during his recuperation at Riverside. It sometimes left him balled up in agony, and the Demerol only made him hallucinate. He did not really want company. But when the pain stirred him awake at night, he could see Lucy sleeping in the hospital bed beside his.

Acts of Devotion

There were other love stories along the way.

Gregory Person and Zenovia Duke, both now 38, had been junior high prom dates in 1987 in Astoria, Queens. They lost touch and then reconnected on Facebook after each had divorced. They saw each other occasionally, but he lived in Queens and she near Albany, so the relationship never got serious.

Not long after they reconnected, Mr. Person’s half-sister died of kidney failure and he pledged to help someone else beat the disease if ever given the chance. Then Ms. Duke learned that she needed a transplant.

On Aug. 31, Ms. Duke received a kidney from a woman in California and Mr. Person sent his to Ohio. As they recuperated at NewYork-Presbyterian, Mr. Person found himself regularly hobbling down to her room. Once they were both back on their feet, they started dating more regularly.