Reply to Nabi et al.

We thank Dr. Nabi and colleagues for their comments and were glad to see their opinions on submucosal fibrosis in achalasia patients and its impact on peroral endoscopic myotomy (POEM) [1]. Their comments open more discussion on this interesting topic.

Both Dr. Nabi’s group and ours reached the conclusion that severe submucosal fibrosis was the major cause for the premature termination of POEM procedures [2]. We also agree that the causes of severe submucosal fibrosis are multifactorial. While long disease duration, intervention history, sigmoid esophagus, and mucosal edema do not present in every patient with severe submucosal fibrosis (for example, mucosal edema was present in only 3 /12 aborted POEM cases in our series), they do present significantly more frequently in patients with fibrosis. In reality, all these factors are interrelated. Patients with long and severe disease require more treatment and they will tend to have an esophagus that is more dilated and edematous, given the chronic food impaction and resultant mucosal inflammation.

Intraoperative decision-making for patients with severe submucosal fibrosis is often difficult. For patients with prior Heller myotomy or failed POEM, we choose an orientation opposite to the prior myotomy in an attempt to avoid scar tissue. We agree that the location of fibrosis is often hard to predict and a second tunnel should possibly be tried, depending on the severity of the fibrosis, the time the first tunnel takes, and whether there is any mucosal injury that is difficult to repair. These cases are rare and need to be discussed individually. Recently, instead of a second tunnel, our group has tried direct myotomy from the incision site in some patients with severe submucosal fibrosis. As a result of the improved room to operate this has provided, we have subsequently been able to enter the submucosal space and proceed with tunneling.

For patients with a very friable and edematous mucosa, in whom mucosotomy will almost certainly result in a difficult repair with standard clips, a delay in performing POEM is a reasonable move. Dr. Nabi and colleagues suggested balloon dilation as a bridging treatment to allow time for the mucosa to improve. This approach also has the added benefit of potentially improving the patients’ nutritional status for later surgery. However, a limitation of such a bridging dilation is that severe mucosal edema rarely occurs in patients without long disease duration and a dilated esophagus, and these patients will most likely eventually require a more definitive treatment (such as POEM), which might then be complicated by fibrosis caused by the dilation. We don’t have enough experience in this situation and would like to see how dilation performs in patients with mucosal edema in terms of the durability of the treatment and adverse events etc.

• References

• 1 Nabi Z, Ramchandani M, Chavan R. et al. Per-oral endoscopic myotomy for achalasia cardia: outcomes in over 400 consecutive patients. Endosc Int Open 2017; 5: E331-E339
• 2 Wu QN, Xu XY, Zhang XC. et al. Submucosal fibrosis in achalasia patients is a rare cause of aborted peroral endoscopic myotomy procedures. Endoscopy 2017; 49: 736-744