Anatomical variations of human paranasal sinuses: Computed tomographic analysis

The present investigation presents the anatomical variations of the human paranasal sinuses using computed tomography scanning [CT scan]. Paranasal sinus CT scans obtained from 300 subjects [120 male and 180 female] were analyzed. Their ages ranged from 15 to 55 years with a mean age [28.4 +/- 8.79]. The maxillary sinus revealed a number of anatomical variations in 30% of cases. They appeared in the form of septated sinus in 16%, sinus hypoplasia in 10 %, and the presence of a tooth in the sinus in 4% of the cases. Examination of the frontal sinus revealed extensive pneumatization of the sinus in 38% hypoplasia in 26 % and aplasia in 4 % of the cases. CT examination of the sphenoidal sinu reveald sinus hypoplasia in 4%, extensive pneumatization of the sinus in 6% and unseptated sphenoidal sinus in 10% of cases. impression of the optic nerve on the wall of sphenoidal sinus was found in 60% of the cases. The internal carotid artery bulged within the lumen of the sphenoidal sinus in 50% of the cases. Anatomical variations of the ethmoid sinus detected by CT included Aggernasi cell [72%], sphenoethmoidal [Onodi] cell [70%], pneumatized middle turbinate [concha bullosa] [56%], enlarged ethmoid bulla [34%], infraorbital ethmoidal [Hailer's] cell [30%], and paradoxically curved middle turbinate [20%].The uncinate process showed hypoplasia in 24%, elongation in 10%, pneumatization [uncinate bulla] in 8%, lateral deviation in 38% and medial deviation in 28% of cases. . It was concluded that various anatomical variations of paranasal sinuses detected by CT could be of great importance in understanding the pathophysiology of sinus diseases and in avoidance of iatrogenic complications during endoscopic sinus surgery

Anatomical and histological study of human lower esophageal segment

This study was undertaken to determine the anatomical characters of the lower esophageal segment [LES] in man and to establish a correlation between these anatomical features and their physiological properties. Manometric studies of LES were performed in 25 normal volunteers. The end expiratory fundic pressure was taken as zero reference and all values were expressed in mm Hg. The manometric characteristics of the lower esophageal segment were determined. The LES length was measured and divided into four equal quarters. Upper gastro-intestinal endoscopy was performed in 12 normal volunteers using Olympus gastrointestinal fibroptic endoscope GIF-K2 type. Twenty-one human specimens were used for gross anatomical studies of muscular thickness and architecture of the LES using microdissection techniques. For histological examination, 22 adult normal human specimens were used; 10 for longitudinal and 12 for transverse sections. . They were proceeded for paraffin sections and stained with haematoxylin and eosin and Verhoeff's stains. Endoscopic examination showed a sharp line of demarcation between the pinkish mucosa of the stomach and the grayish mucosa of the esophagus. Manometric study showed a higher pressure zone at the LES of the esophagus. The length of this high pressure zone is variable from subject from subject to another. There is an axial asymmetry in the pressure of LES. The pressure is higher in the middle two quarters of the LES than the cranial and caudal quarters. Microdissection and histological techniques showed asymmetry in the thickness of the inner circular muscle layer of the LES. The area of maximum thickness is considered as the gastro-es0phageal ring [GER]. The thickness of the circular muscle layer is tapered above and below the GER i.e there is axial asymmetry. The degree of thickness of the circular muscle layer is variable in relation to the different Walls of the the LES i.e there is radial asymmetry. There was close correlation between manometric records and muscular thickness in the LES. The area of maximum pressure in the middle part of LES coincided with the area of highest thickness of the inner circular muscle layer at the gastroesophageal ring [GER]. The extent of this muscular thickness is equal to the length of the high pressure zone. The lower esophageal sphincter is not a ring sphincter due to the presence of radial asymmetry in the circular muscle layer. In addition, there is an axial asymmetry in the thickness of inner circular muscle layer. The asymmetric muscular thickening at the gastro-esophageal junction is mirrored in the manometric images of the lower esophageal high pressure zone. Manometric assessment of the lower esophageat segment, therefore, reflects muscular structure and architecture of the human gastro-esophageal junction