Read the whole paper not just the abstract

Here is another installment in my series of posts about why you should read the entire paper and not just the abstract. (See others here, here and here.)

A paper in the February 2013 issue of the Journal of the American College of Surgeons describes 15 cases of median arcuate ligament syndrome treated with laparoscopic surgery.

Median arcuate ligament syndrome (MALS) is somewhat controversial. It is said to be due to impingement of the median arcuate ligament (a portion of the diaphragmatic crura) on the celiac artery causing a narrowing and decreased perfusion of the stomach. Symptoms are abdominal pain after eating, nausea and weight loss. It is often diagnosed in patients who have been worked up for many other suspected problems without finding anything.

The paper notes that 10% to 60% of people without symptoms have narrowing of the celiac artery.

The abstract reports resolution of the pain for 14 of the 15 patients who had the surgery as well as a significant mean decrease in celiac velocity indicating resolution of the narrowed area postoperatively.

It also mentions that one patient required conversion to open surgery but doesn't say why.

On reading the whole paper, one learns that the conversion to open occurred in the only case that was done with robotic assistance.

The authors state that the 2 mm injury to the aorta was the result of the robotic instrument being too large and "the absence of haptic feedback," which is robot-speak for "you can't feel anything."

That is one drawback of the robot. With robotic instruments the sense of touch is simply not present. Although the fingertips used in old-fashioned open surgery are much more sensitive than instruments used in standard laparoscopic surgery, those instruments do enable the surgeon to at least feel some variations in tissues

The aortic tear led to two liters of blood loss and an operative time of just under 8 hours.

The abstract says all but one patient had complete resolution of pain, but the paper says the amount of decrease in the Doppler celiac velocity "did not correspond to the degree of symptom resolution."

And you can see that the differences in preop (red) and postop (green) velocities are pretty modest in 7 of the 10 patients who had them measured even though the mean difference was significant at a p of 0.005. In addition, the postop values all hover around 200 cm/sec, which, in the presence of symptoms, was the threshold for doing the operation.

In fairness, of the 13 patients who were interviewed, all said they were satisfied with the outcome of the surgery and would go through it again.

In some ways, MALS reminds me of internal mammary artery ligation, which was once touted as a cure for angina pectoris (chest pain of cardiac origin). Over 50 years ago, randomized trials which included a sham operation—incisions were made, but the arteries were not ligated—showed that ligating the arteries was no better than the sham operation for relieving pain.

It might be time for such a trial in MALS, only let's skip the robot for this one.

Thanks to Dr. Michael Burchett for alerting me to the MALS paper.