Friends of mine in Jordan have been raising money to help a dearly loved neighbour. Urwah is a Syrian in his thirties, who was caught in crossfire during an earlier phase of the country’s civil war. Several bullets struck him in the lower abdomen, wreaking havoc around the bladder area. Health care, like the rest of civilised society in Syria, has fragmented in the chaos, and Urwah was fortunate that there was a nurse able to provide him with emergency treatment, arresting blood loss and stitching up his wounds. He survived and, when he was able, fled to Amman, where he has taken refuge.
The first-aid surgery that saved his life was inevitably far short of what would have been performed by a surgeon with proper facilities, leaving substantial residual damage and shrapnel internally. Urwah’s body has done the only thing it knows to do in the circumstances: healing by scar formation.
As time has passed, the scar tissues have contracted, constricting and distorting the normal pelvic structures. The tubes taking urine from his kidneys have been caught in this process, becoming so narrow that little flows through them. This is causing chronic back pressure on the kidneys, resulting in renal failure, which, without treatment, will kill him.
Sorting out this unholy mess will be a complex, multi-stage process requiring considerable surgical expertise. Urwah’s friends found a Belgian surgeon who was willing to perform what will be at least three operations free of charge, but this still left them needing to find €20,000 to fund flights and hospital inpatient costs in Antwerp. They were launching a web-based appeal against a ticking clock and I have to admit I felt pessimistic. As special as Urwah is to them, I wondered whether total strangers would find the case of an adult male caught, however unwittingly, in a firefight emotive enough to prompt them to donate hard cash. To be brutally frank, Urwah is not a doe-eyed five-year-old whose picture would pull at everyone’s heartstrings.
The aspect of Urwah’s story I find particularly tragic is that it is his body’s own reparative capacity that is slowly killing him. No one knows for sure why damaged mammalian tissue tends to heal by scarring. In theory, it needn’t: there are plenty of examples in the animal kingdom of healing by regeneration. Salamanders, for instance, are able to regrow extremely complex structures such as tails, limbs, jaws and even eyes. And certain human tissue is capable of regeneration: our livers and bones, for example, as well as the lining of the womb. However, for the vast majority of bodily damage, human beings – along with all other mammals and many other higher animal species – repair injury by scarring.
On the face of it, scar tissue seems, in all sorts of ways, second best. It is composed of the same structural substance, collagen, that normal tissues are built on, but while collagen fibres are usually arranged in multidirectional meshes, in scar tissue they often align in only one direction. The resultant tissue is neither as strong, nor anything like as flexible, as the material it’s replacing.
Scars are, in essence, functionless. They don’t develop replacement components such as muscle cells, sweat glands or hair. They also contract over time, the specialised cells responsible for the collagen production “pulling” the wound tight over the first few months.
This can cause a variety of problems, dependent on location. Scarring of fingers causes deformity and affects dexterity; around the full circumference of a limb, it impairs circulation as it contracts. The visual axis of the eye can be distorted. Scarring inside the abdominal cavity may lead to bowel obstruction, which is potentially fatal. All of which prompts the question: why do we heal by such a problematic process?
Even trivial wounds can be life-threatening if serious infection takes hold. The evolutionary priority has probably been to mend breaches as quickly as possible. Regeneration requires cells to regain the ability to give rise to any form of tissue and then to differentiate and organise into the complex structures that were originally present.
That takes time. Scarring is the biological equivalent of chucking a mixer-load of quick-setting cement into a hole – inelegant but fast and effective. This probably matters more to higher animals such as human beings than it does to regenerators such as the salamander, because our relatively few offspring need us to stay alive for many years in order for them to stand a chance of surviving to reproductive maturity.
Today, we can treat most infections with antibiotics (assuming that we keep a lid on resistance), and so being able to “switch off” scarring and “switch on” a regenerative pathway in human tissue would transform medical practice. This is a current focus for molecular-biological research. In the meantime, people such as Urwah have to contend with the complications of scarring. Fortunately, my anxieties about his fundraising appeal proved groundless and the €20,000 target was reached swiftly, all of which helps restore one’s faith in the very best side of human nature.