CARACAS, Venezuela - Venezuelan President Hugo Chavez announced plans to travel to Cuba as early as Tuesday for more medical treatment after spending much of the past 18 months fighting cancer.
In a written request to the legislature, Chavez said doctors have recommended he "begin special treatment consisting of various sessions of hyperbaric oxygenation" and physical therapy to continue "consolidating the process of strengthening health."
The request did not provide more details about the treatment or Chavez's condition and was promptly approved by allied lawmakers at a special session in the city of Maracay. National Assembly President Diosdado Cabello read the request on television.
It said Chavez would travel to Cuba as soon as Tuesday. It did not say how long he will stay, though it said he would be back by Jan. 10, when he is being sworn in for a fourth term. Venezuelan law requires presidents to receive legislative approval before leaving the country for extended periods.
The treatment that Chavez is to undergo generally involves breathing pure oxygen while in a pressurized, sealed chamber. Its value is well-established for treating burns, carbon monoxide poisoning and some other medical conditions, and to aid wound healing and help repair bone and tissue damaged by radiation treatments.
However, the American Cancer Society says there is no evidence the treatment can cure cancer.
Hyperbaric oxygen treatment is employed by doctors in Cuba for the rehabilitation of patients with chronic illnesses, said Jesus Pena, a Venezuelan internist with a private practice in Caracas. But Pena said the announcement after a period of silence about Chavez's condition raises suspicions about the reasons behind the treatment.
The 58-year-old president first underwent cancer treatment in Cuba in June 2011 and suffered a relapse in February. He has since said he's recovered from the pelvic cancer and won re-election in October.
Throughout his previous chemotherapy and radiation treatments, Chavez kept many details of his illness secret, including the type of cancer and the precise location of the tumors.
Opposition lawmaker Alfonso Marquina expressed concern about what he said seems to be a "veiled or deliberate attempt to continue creating uncertainty."
Marquina told The Associated Press in a phone interview that if Chavez is travelling to Cuba for normal medical treatment as his request says, "the correct thing to do would be for a much more precise medical report to be given, and to not continue on with this sort of permanent uncertainty."
Dr. Michael Pishvaian, an oncologist at Georgetown University's Lombardi Comprehensive Cancer Center in the United States, said several of his patients have received hyperbaric oxygen treatment, usually to promote the healing of wounds or damage to nerves and muscles that can be caused by radiation therapy. Pishvaian said such cases are unusual.
"These are definitely cases that the patients are really suffering from the side effects ... of the radiation therapy, and we don't know how to help them and hyperbaric oxygen is kind of something we reach for as a last resort," Pishvaian said.
He said that while it's unclear why Chavez is having the treatment, "it may be promoting wound healing if there's something about the surgical site or his prior radiation sites that aren't healing well."
Chavez last appeared publicly during a televised meeting on Nov. 15, prompting some critics to publicly wonder where he went after his election win.
Chavez was absent on Tuesday from a military air show in Maracay where some Venezuelans had speculated he could reappear.
Before the announcement of Chavez's plans to return to Cuba, opposition newspaper editor Teodoro Petkoff published an editorial in the daily Tal Cual on Tuesday criticizing the president's long absence from the public eye.
Under the headline "The invisible man," Petkoff said: "The health of those who govern can't be a secret."
AP Chief Medical Writer Marilynn Marchione in Milwaukee, Wisconsin, and AP writer Ian James in Caracas contributed to this report.