The science behind replanting severed limbs

How do you replant a severed limb?

Last week’s freak accident at the MRT Ayala station that involved a woman falling onto the tracks and severing her right arm prompted this unlikely question. 

On “Kapuso Mo, Jessica Soho,” Dr. Tristram Montales, an orthopedic doctor of the Philippine General Hospital explained how doctors reattach limbs that have been cut off from the body.

[Editor’s Note: Dr. Montales wasn’t part of the team of doctors who attended to the MRT victim. He only served as a resource person for the program.]

The process

To begin, reattaching severed limbs takes two teams of doctors: one team to focus on the body, and another on the severed limb. 

“Ginagawa ‘yun para mas mapabilis,” says Montales.

The operation starts with repairing the bone:

“Magsisimula tayo sa buto, kailangan malagyan ng bakal para hindi na gumagalaw. From there, next priority is the artery, ‘yung ugat na magbibigay ng dugo – ideally within 4 to 6 hours dapat na-resume na ‘yung flow.”

Putting together the arteries should also be ideally done under an operating microscope. 

“Para ‘yung magnification, ‘yung kung gaano kalinaw mo maire-repair nang maganda ‘yung ugat na walang tagas, na hindi lumalabas ‘yung dugo,” Montales explains.

After the arteries, repairing the veins, attaching the muscles, and fixing the nerves come next.

Nerve repair, actually, is a crucial step: “Kombinasyon kasi ‘yung nerves. May nerve na nagbibigay ng pakiramdam, meron naman na nagbibigay ng galaw. So crucial to match them correctly.”

The outcome is a little unpredictable, Montales admits. He gave a projection of 80 percent success rate, noting that the movement of the attached limb may no longer be normal.

Crucial elements

According to Montales, the success rate of replanting a severed limb depends greatly on time. Citing a “golden period” in such accidents, he explains that the severed limb should be attached within six to ten hours.

“Kailangan mong isipin ‘yung muscle ng natitirang bahagi eh,” he explains. “Habang nadedelay kasi ‘yung pagbalik ng daloy ng dugo, malaki ang tiyansang mamamatay ‘yung muscle, so nagkakaroon ng secondary na cell death or pagkamatay ng muscle.”

The difficulty of reattaching limbs as well as its success rate also depend on which limb is severed:

“Kapag putol sa daliri, mas maganda ‘yung resulta. We’re talking as high as 80 percent success rate na mababalik siya, mabubuhay siya, magagamit siya. Sa level ng kamay, wrist at forearm, maganda rin.“

Difficult reattachment operations, meanwhile, would be of severed limbs from the elbow up. — LA, GMA News