Morphology of human fetal enteric neurons: A comparative study of different segments of the colon

OBJECTIVES

The Enteric Nervous System (ENS) present in the wall of the gut is currently being explored because of its influence on the gut and beyond. In this context, the morphology of developing ENS has not been completely understood in humans due to lack of adequate literature. The aim of the present study was to observe the morphology of the enteric neurons in the human fetal colon and compare the findings in ascending colon a midgut derivative and descending colon a hindgut derivative at various weeks of gestation (WG).

MATERIAL AND METHODS

Tissue samples from 15 aborted fetuses (11 WG to 2 months postnatal) were processed for Cresyl violet, H & E staining, and NADPH Diaphorase histochemistry. The morphometric analysis was done by calculating the neuronal number density and neuronal fractional area. The Student t-test; Mann-Whitney test and Wilcoxon signed-rank test were used to analyze the data.

RESULTS

The muscularis externa with two distinct layers was visible as early as 13 WG and the muscularis mucosae was first observed at 18 WG. The size of the myenteric neurons appeared to be larger with increasing weeks of gestation suggesting a process of neuronal maturation. The neuronal number density and neuronal fractional area seemed to be reduced with advancing fetal age. There was no marked difference between the ascending and sigmoid colon. At 23 and 26 WG, a mature pattern of nitrergic innervation was observed.

CONCLUSION

This study is done on human fetal tissue samples unlike previous studies on animal samples to comprehend the morphology of developing ENS. It will aid in understanding the effect of ENS on various neurological disorders.

Neuromuscular variations in the gluteal region - Embryological basis and clinical significance

ABSTRACT

Piriformis, is a key muscle in the gluteal region. Under its lower border sciatic nerve and inferior gluteal nerves exit. During routine educational dissection of the lower limb, bilateral gluteal regions in fifteen cadavers (30 gluteal regions) focusing on the variations of inferior gluteal nerve and sciatic nerve with respect to piriformis muscle were observed in the department of anatomy, All India Institute of Medical Sciences, New Delhi, India. In one of the left sided specimens, inferior gluteal nerve had an abnormal course, piercing superior belly of piriformis muscle instead of emerging through the lower border of it along with variation of the sciatic nerve. The common peroneal component of the sciatic nerve was coming out between the two anomalous tendinous slips of the piriformis muscle, whereas the tibial component, emerged along lower border of the piriformis muscle bilaterally in the same cadaver. In the remaining cadavers, there were no variations of the inferior gluteal nerve with respect to the piriformis muscle. But in another cadaver, there was a similar variation of the sciatic nerve bilaterally. Inferior gluteal and sciatic nerves, when compressed by muscle belly or tendinous slips of the piriformis muscle, may cause lurching gait and sciatica respectively. Knowledge of the different variations of these peripheral nerves with respect to the piriformis muscle is important to clinicians and surgeons for the accurate diagnosis and intervention.

Predictors of Functional Outcome in Unstable Ankle Fractures Treated Surgically - A Prospective Cohort Study

Introduction:

Unstable ankle injuries require anatomical reduction and stabilisation for optimal outcome. In spite of adequate care, a few patients have poor outcome. In this study, we assessed the risk factors that predict the clinical outcomes in surgically treated unstable ankle fractures.

Material and methods:

This prospective cohort study was conducted on 68 patients who underwent surgical management for an unstable ankle injury. Demographic details, fracture type and associated medical comorbidities were recorded. Pre-operative radiographic assessment was done for all patients. At the end of one year follow-up, clinical (American Orthopaedic foot and ankle society-AOFAS and Olerud-Molander ankle - OMAS) scores and radiological parameters were assessed and analysed.

Results:

Fracture dislocation (0.008), diabetes mellitus (0.017), level of alchohol consumption (0.008) and pre-operative talocrural angle (TCA) > 100° (0.03) were significant predictors of poor outcomes as per AOFAS. Fracture dislocation (0.029), diabetes mellitus (0.004), pre-operative TCA > 100° (0.009), female gender (0.001), age more than 60 years (0.002) and open injuries (0.034) had significantly poor outcome as per OMAS. Other parameters (smoking, hypertension, classification, syndesmotic injury, medial clear space and tibiofibular overlap) did not affect the outcome significantly.

Conclusion:

Our study showed that poor outcome predictors in unstable ankle fractures are age >60 years, female gender, diabetes mellitus, alcohol consumption, fracture dislocation, open fractures and pre-op TCA >100°.