In a major right-to-die case, the court ruled 6 to 0 that the wife of a Stockton man severely injured in a car accident could not withdraw his feeding tube because he had left no formal order of his wishes.

Robert Wendland, 49, died last month of pneumonia after a six-year battle in which his wife wanted to let him die and his mother fought to keep him alive.

The case is expected to have national repercussions because Wendland was not in a coma or near death. Instead, he lingered in a state some doctors described as "minimally conscious," partially paralyzed and unable to speak, walk or control his bowel functions.

Courts have allowed families to withdraw life-sustaining treatment for patients in a comalike state. The state Supreme Court also has recognized that a mentally competent adult has a fundamental right to refuse life-saving medical treatment.

But few courts have ruled on one of the most agonizing decisions: whether family members can stop treatment for loved ones still conscious but not competent to decide their own fate.

In Wendland's case, his wife and three children said he did not recognize them. But his mother said that he kissed her hand and could play catch with a ball.

Before the accident, the auto parts salesman told his wife and brother that he would not want to be kept in a vegetative state.

But the justices said those statements were not enough.

A conservator must show "by clear and convincing evidence, either that the conservatee wished to refuse life-sustaining treatment or that to withhold such treatment would have been in his best interests," Justice Kathryn Mickle Werdegar wrote.

The court said its ruling would not affect most decisions made by conservators for loved ones unable to make their own choices.

"Only the decision to withdraw life-sustaining treatment, because of its effect on a conscious conservatee's fundamental rights, justifies imposing that high standard of proof," Werdegar said.

"The decision to treat is reversible," she added. "The decision to withdraw treatment is not."

APPEALS COURT OVERTURNED

The court overturned a state appeals court decision that rejected that "clear and convincing" standard. The lower court said that a state law required only that the wife, Rose Wendland, as her husband's conservator, act in good faith.

Yesterday's decision was consistent with rulings in Michigan and Wisconsin refusing to allow guardians of neurologically damaged patients to withdraw life-sustaining treatment.

Janie Hickok Siess, the lawyer for the mother, Florence Wendland, said she was in "complete joy" over the court's ruling.

"A lot of people's lives will be saved," she said. The decision also comes as a relief to disability groups that had warned that conservators would try to abuse their powers. "They know if someone is in Robert's condition, their feeding tube cannot be pulled without the strictest scrutiny of that decision, " Siess said.

Rose Wendland called the ruling "a terrible decision."

"Those justices truly do not get it," she said. "I don't know how clear and convincing you can make your decision for someone who does not know the law."

San Francisco attorney James Braden, who was appointed by the court to represent Robert Wendland, said that yesterday's decision "eliminates the practical usefulness of a conservator's decision to end life-sustaining treatment."

WARNING FROM EXPERTS

Bioethics experts warned that few people actually write an advanced directive of their wishes or appoint a surrogate to make medical decisions for them.

Unless you take these steps, "you're not going to be able to count on your end-of-life wishes being honored unless you have been extraordinarily specific in what you say to your loved ones," said Oakland lawyer Jon Eisenberg, who filed a friend-of-the-court brief on behalf of six health care associations and 43 individual bioethicists.

"The decision fails to grapple with the fundamental issue of quality of life," said Alan Meisel, who teaches bioethics at the University of Pittsburgh and is author of the book "The Right to Die."

Robert Wendland was severely injured in September 1993 when his truck rolled over in a solo accident.

He was in a coma for several months and eventually regained consciousness. With therapy, he was able to throw and catch a ball and operate an electric wheelchair with assistance. But he remained severely disabled both mentally and physically.

Two years later, Rose Wendland asked that her husband's feeding tube, which had come out several times, not be reinserted. The hospital's ethics committee agreed to her request. But Wendland's mother received an anonymous call from a hospital telling her of the plan.

Florence Wendland obtained a restraining order preventing her son's wife from taking any action.

During the trial, Rose Wendland said her husband had told her before the accident that he would not want to be kept alive in a vegetative state.

He expressed his concerns when Rose Wendland decided to turn off the life- sustaining respirator for her father, who was near death from gangrene. "I would never want to live like that, and I wouldn't want my children to see me like that," she recalled Robert Wendland telling her.

But the trial judge ruled in favor of Florence Wendland, saying that Rose Wendland failed to show with "clear and convincing evidence" that her husband would want his life-sustaining treatment to be withdrawn. He noted that Robert Wendland was not in a persistent vegetative state or suffering from a terminal illness.

A state appeals court reversed that decision, saying that the trial judge set too a high standard.

E-mail Harriet Chiang at hchiang@sfchronicle.com.