Effect of inter-swallow interval on striated esophagus peristalsis; a comparative study with smooth muscle esophagus.

BACKGROUND: Effect of inter-swallow interval on the contractility of smooth muscle esophagus is well-documented. However, the effects on peristalsis of the striated esophagus have not been systematically studied. A better understanding of striated esophagus motor function in health and disease may enhance the interpretation of manometric studies and inform clinical care. The aim of this study was to assess the effect of inter-swallow interval on striated esophagus compared to findings with that of the smooth muscle esophagus. METHODS: We performed two sets of studies to (1) determine the effect of various inter-swallow interval in 20 healthy volunteers and (2) assess the effect of ultra-short swallow intervals facilitated by straw drinking in 28 volunteers. We analyzed variables using ANOVA with Tukey's pairwise comparison and paired t-test. KEY RESULTS: Unlike smooth muscle esophagus, the striated esophagus contractile integral did not change significantly for swallow intervals ranging from 30 to 5 s. On the contrary, striated esophagus demonstrated absent or reduced peristalsis in response to ultra-short (<2 s) intervals during straw-facilitated multiple rapid swallows. CONCLUSIONS AND INFERENCES: Striated esophagus peristalsis is subject to manometrically observed inhibition during swallows with ultra-short intervals. Inter-swallow intervals as short as 5 s that inhibit smooth muscle esophagus peristalsis do not inhibit striated muscle peristalsis. The mechanisms of these observations are unknown but may relate to central or myenteric nervous system influences or the effects of pharyngeal biomechanics.

Pharyngeal peristaltic pressure variability, operational range, and functional reserve.

The present understanding of pharyngeal motor function remains incomplete. Among the remaining gaps of knowledge in this regard is the magnitude of variability of pharyngeal peristaltic pressure amplitude. Although variability can pose difficulty in interpretation of manometric findings, its magnitude can inform the operational range and reserve of the pharyngeal contractile function. We aimed to define the intra- and intersubject and intersession variability of select pharyngeal manometric parameters and, using this information, determine the number of swallow repetitions for acquiring reliable pharyngeal manometric data. We recorded pharyngeal peristalsis in 10 healthy subjects (age: 50 ± 25 yr, 5 women) by high-resolution manometry during two separate sessions of 20 sequences of 0.5-ml water swallows. Two-way ANOVA showed significant variation in the mean peak peristaltic pressure value across sites (P < 0.0001) as well as within the data at each site (P < 0.0001). Similarly, the pharyngeal contractile integral exhibited significant inter- (P = 0.003) and intrasubject (P < 0.001) variability. The Shapiro-Wilk normality test showed mixed results, in that some sites showed normally distributed data, whereas others did not. A robust Monte Carlo simulation showed that the nominal sample size was different for various tested metrics. For a power of 0.8, commonly accepted as an adequate threshold for acceptable statistical power, the optimal sample size for various peristaltic parameters ranged between 3 and 15. There is significant intra- and intersubject variability in site-specific and integrated parameters of pharyngeal peristalsis. The observed variance indicates a significant operational range and reserve in pharyngeal contractile function while necessitating parameter-specific sample size for reliable results.NEW & NOTEWORTHY Intra- and intersubject variability are significant and different at various sites within the contractile pharynx. In addition, significant swallow-to-swallow and subject-to-subject variability exists in pharyngeal contractile integral. The range of intrasubject variability indicates the existence of broad operational range and reserve. Lastly, our variability studies informed Monte Carlo and power analyses, yielding estimates of sample size that would ensure accurate representation of pressure metric variability.

Portal annular pancreas: the pancreatic duct ring sign on MRCP.

Portal annular pancreas is a rare pancreatic variant in which the uncinate process of the pancreas extends and fuses to the dorsal surface of the body of the pancreas by surrounding the portal vein. It is asymptomatic, but it can be mistaken for a pancreatic head mass on imaging and could also have serious consequences during pancreatic surgery, if unrecognized. We report this case of a 53-year-old female patient who was diagnosed to have portal annular pancreas on the basis of an unusual course (ring appearance) of the main pancreatic duct on magnetic resonance cholangiopancreatography, not described earlier in the radiology literature.

Inoperable aggressive mesenteric fibromatosis with ureteric fistula. Case report and literature review.

The purpose of our report is to illustrate an aggressive case of mesenteric fibromatosis in a 17-year-old girl with a ureteric fistula and to review imaging and pathological features, natural history and treatment options of this disease. Our patient underwent computed tomography that revealed a widespread intra-abdominal mass. The necrotic centre of this mass had a fistulous communication with the right ureter. Fibromatoses represent a spectrum of uncommon benign conditions characterised by proliferating fibrous tissue. The deep intra-abdominal form of mesenteric fibromatosis (MF), one of the rare subtypes of the 'fibromatoses' or 'desmoid tumours', grows rapidly and may become extensive. Surgery provides good results in limited disease and non-surgical modalities in cases of unresectable and residual disease.