Per-oral Pyloromyotomy (POP) for Medically Refractory Gastroparesis: Short Term Results From the First 100 Patients at a High Volume Center

OBJECTIVE

For patients with gastroparesis, temporary pyloric disruption has been shown to improve symptoms and gastric emptying. Per-oral pyloromyotomy (POP) is an innovative endoscopic procedure to divide the pylorus from within a submucosal tunnel, as a corollary to surgical pyloromyotomy. Here we evaluate subjective and objective outcomes 12-weeks after POP at a high volume center.

METHODS

The first 100 consecutive patients undergoing POP were included, with procedure dates between January 2016 and October 2017. Patients were evaluated using the Gastroparesis Cardinal Symptom Index (GCSI), and 4-hour solid-phase scintigraphic gastric emptying studies (GES) prior to procedure and at 90 days post-POP RESULTS:: The study cohort was 85% female with a mean age of 45.0 ± 14.6 years. Gastroparesis etiologies were divided among idiopathic (56%), diabetic (21%), postsurgical (19%), and other in 4%. There were 67% of the patients who had previous endoscopic or surgical interventions for gastroparesis. Most POP procedures were performed in the operating room (97%) and were completed in an average of 33 minutes. Ten patients incurred complications (10%), which included 1 diagnostic laparoscopy and 2 cases of gastrointestinal bleeding. Overall GCSI improved from a preoperative mean of 3.82 ± 0.86 to 2.54 ± 1.2 (P < 0.001). The improvement in each GCSI subscore was also highly statistically significant. Among the patients with postoperative GES available, 78% had objectively better 4-hour emptying with a mean improvement in retention by 23.6% (P < 0.001). This included 57% of patients with normal gastric emptying post-POP.

CONCLUSION

For patients with medically refractory gastroparesis, POP results in both subjective and objective improvement in the majority of patients. Prior intervention does not obviate POP as a therapeutic option. POP should be included along the treatment algorithm for patients with gastroparesis as an organ-sparing procedure.

The effects of alternative splicing on transmembrane proteins in the mouse genome

Alternative splicing is a major source of variety in mammalian mRNAs, yet many questions remain on its downstream effects on protein function. To this end, we assessed the impact of gene structure and splice variation on signal peptide and transmembrane regions in proteins. Transmembrane proteins perform several key functions in cell signaling and transport, with their function tied closely to their transmembrane architecture. Signal peptides and transmembrane regions both provide key information on protein localization. Thus, any modification to such regions will likely alter protein destination and function. We applied TMHMM and SignalP to a nonredundant set of proteins, and assessed the effects of gene structure and alternative splicing on predicted transmembrane and signal peptide regions. These regions were altered by alternative splicing in roughly half of the cases studied. Transmembrane regions are divided by introns slightly less often than expected given gene structure and transmembrane region size. However, the transmembrane regions in single-pass transmembranes are divided substantially less often than expected. This suggests that intron placement might be subject to some evolutionary pressure to preserve function in these signaling proteins. The data described in this paper is available online at http://www.affymetrix.com/community/publications/affymetrix/tmsplice/.

Bacillary angiomatosis in a renal transplant recipient

A case of bacillary angiomatosis infection presenting as a skin nodule in a renal transplant recipient was found. The patient was taking cyclosporine, prednisone, and mycophenolate mofetil at the time of presentation. The bacillary angiomatosis responded to 6 months of therapy with oral erythromycin.

Curing the 'nitrate blues'

Methemoglobinemia should always be considered in the differential diagnosis of cyanosis in patients with normal arterial oxygen tension. Cyanosis that is brownish and not relieved by oxygen administration should lead to consideration of the diagnosis. A normal or elevated PaO2 value further suggests the presence of methemoglobinemia. Mild cases can be treated by removing the offending agent. In more severe cases, intravenous methylene blue and, if necessary, packed red cells or exchange transfusions may be given.