Anatomy of a Miracle

This post is dedicated to a fine young man who recently eluded medical miracles and left behind many, many people who love him dearly.

Not all medical miracles are inexplicable. Working for a company that makes endovascular devices, I can see the world of medical miracles becoming more navigable. As an investigator with the Quality Engineering group, I encounter more medical mishaps than medical miracles. It is only when our medical devices fail that I am tasked with figuring out what happened and following up accordingly. I peruse the gory details in the case files about unsuccessful vessel closures or incomplete stent deployments until I find the root cause of the failures so that I can prevent future mishaps.

One of my first cases was a “medical mishap” involving a device designed to close up the puncture site in a blood vessel. Unlike a traditional suture, this device works like a stapler. After the device is inserted into the body, “wings” are opened to locate the wall of the punctured vessel. Then, a tube is advanced until it is positioned against the wall. Finally, a circular clip is fired from the device, crimping the hole shut. Simultaneously, the wings collapse and the device can then be safely removed from the body. In this particular “mishap”, the physician was unable to remove the device from the puncture site after he had fired the clip. The wings had not collapsed, so they were stuck in the vessel under the clip. A “control wire” had also snapped, so when the doctor pulled the device away, the control wire was still attached to the vessel locator wings in the body. The doctor had to literally wiggle the rest of the device out of puncture site. Fortunately, the clip had fired successfully and surgery was not necessary.

The device that the physician sent back with his complaint was a mess. There was severe nylon carving, there was misalignment of parts all over and there was evidence of incomplete component deployment at every step. There was a long list of anomalies that could be observed just by looking the device. It was my job to make sense of the list of anomalies and to explain what happened. After several experiments and failure recreation attempts, I finally fit the puzzle pieces together into a sequence of events that was both probable and consistent with the symptoms.

It all started when the physician held the device at a wrong angle and caused the nylon tubes to get carved. The carving was so intense that the nylon blocked the path of the tube and the device did not align the way it was supposed to. However, the tubes had advanced just enough for the trigger to be functional. So, when the trigger was pressed, the clip fired and closed the hole, but the impact from the firing snapped the control wire that was exposed as a result of the misalignment. Meanwhile, the intense nylon build-up had held the wings flat, so they did not collapse like they should have.

Then I took another look at the evidence, and the pronounced sequence of events. Besides the several things that went wrong with the procedure, one thing bewildered me. How the HECK did the clip manage to fire? Carving by itself usually leads to the device getting stuck in the middle of the procedure. Misalignment of components usually leads to the device “pinching” the vessel. Blocked tubes usually lead to the clip getting stuck in the device. None of these scenarios would have ended in a successful procedure. However, amidst all this drama, the clip in this procedure had somehow found its way to the puncture site and had successfully closed the hole. My formal investigation was over, but I ran some more tests in the hope of finding something I could marvel at. Sure enough, I saw that the carving had somehow occurred just past the trigger, so when the device did get stuck, it was not an issue. The carving had then blocked the tubes and caused the incomplete advancement of the device. However, the doctor was holding the device at a wrong angle, so the misalignment of the device in the body prevented the “pinching”. The incomplete device advancement had also caused the tip of the device not to “flare out” like it should have. The edge of the tube would have sliced the vessel like a cookie cutter, but that did not happen, since the control wire had snapped after the trigger was pressed. Therefore, the major part of the device could be removed, leaving behind just a wire. It was also fortunate that the wings did not collapse, as they would have gotten stuck in the clip. Somehow, all these “wrongs” had somehow made a right. Of these failure symptoms that had coincidentally co-existed, if even one of them had been absent, there would have been serious consequences. Marvelous indeed.

The funny thing is that the doctor and the patient will probably never know how lucky they were. The patient is probably lamenting the soreness he must have felt from the traction that was used to pull the wire out. The doctor probably feels like the procedure was botched. They have no idea that the success of the actual clip application was a fluke that defied all kinds of odds. This incident is probably a medical mishap in the books of both the doctor and the patient, when, in fact, it is a miracle that so many potentially catastrophic circumstances canceled each other out like that.

Maybe there is actually no such thing as a medical mishap. A medical mishap is just… a medical miracle that didn’t happen exactly the way we expect. Even when technology thins the line between medical efforts and miracles, a miracle is a miracle. Whether a physician can explain it or not, a miracle is a miracle. Miracles happen because of the skilful use of medical equipment, or it happens by accident. No one is entitled to miracles. Sometimes they happen. Sometimes they don’t. More often than not, they are subtly present and conspicuously absent.