Chirurgie du cancer

Abstrait

2nd European Otolaryngology ENT Surgery Conference & International Conference on Craniofacial Surgery October 16-18, 2017, Rome, Italy.

Kurt J Knowles

Oral foregut duplication cysts are extremely rare lesions with approximately 57 cases reported. They are congenital cysts, located in the anterior or ventral tongue, and occur predominantly in males. They are lined by one or more types of epithelia which are limited to gastric, intestinal or respiratory epithelium. The differential diagnosis includes lymphangioma, hemangioma, ranula, epidermoid cyst, teratoma and less likely a malignant process. They are congenital and if present at birth or early infancy, and they can cause difficulties in feeding, swallowing, speech, and airway obstruction. If discovered in utero and suspected to be large enough, they may also cause respiratory distress and optimal patient care would dictate that ENT be present at delivery. Even a small lesion if left untreated may cause speech difficulties in toddlers so definitive treatment is required. What is fascinating about oral foregut duplication cysts is the possible histogenesis. They are always comprised of one or more upper GI and/or respiratory tissues. This trapped primitive tissue, apparently removed from its normal milieu, still has the capability to differentiate into gastric, intestinal or respiratory tissue, singly or in combinations of epithelia as was this case. This suggests that the trapped cells are preprogrammed to differentiate along certain possible cell lines but are influenced by some unknown local or distant environmental factors. The form and function of the small intestine of farm animals are similar between species, but the stomachs and large intestines vary considerably. The motility patterns in both the small and large intestine are similar among the species. In the small intestine, the fundamental unit of electrical activity is the slow wave, which is a subthreshold fluctuation in membrane potential. Slow waves are constantly propagated from the stomach to the rectum. When an additional stimulus causes the membrane potential to exceed the excitation threshold, a spike or electrical response activity occurs, which is usually accompanied by contraction. Almost all spike activity in the intestine is superimposed on slow waves, which are important in controlling frequency and velocity at which spiking events occur. The spiking activity, also known as the migrating myoelectric complex, is the myoelectric pattern in the stomach and small intestine of fasted nonruminants, fed and fasted ruminants, and pigs and horses fed ad libitum.1 There are three phases of the migrating myoelectric complex. There is very little muscle contraction or transit of gut contents during the quiescent phase. During the irregular phase, contractions mix the intestinal contents and propel them in an aboral direction. The activity front is accompanied by intense muscular contraction that obliterates the lumen, preventing backflow of content as it propagates, or migrates, down the intestine. In nonruminants, and pigs and horses fed periodically, feeding abolishes the migrating myoelectric complex for several hours. It is replaced by the fed pattern, characterized by intermittent spike activity resembling the irregular phase.Abnormal motor function can take the form of increased or decreased motility. Peristalsis and segmenting movements are usually affected equally and in the same manner. Motility depends on stimulation via the sympathetic and parasympathetic nervous systems, and is thus dependent on the activity of the central and peripheral parts of these systems and on the intestinal musculature and its intrinsic nervous plexuses. Autonomic imbalance, resulting in a relative dominance of one or other system, is manifested by hypermotility or hypomotility, and can arise as a result of stimulation or destruction of hypothalamic centers, the ganglia, or the efferent or afferent peripheral branches of the system. Debility, accompanied by weakness of the musculature, or severe inflammation, such as occurs in acute peritonitis or after trauma, or infarction, results in atony of the intestinal wall. Less severe inflammation, such as occurs in mild gastritis and enteritis, can result in an increase in muscular activity and increased propulsive activity. Abnormalities in intestinal motility can result in diarrhea or constipation and adversely affect digestion and absorption of ingesta. Normal cecal and colonic myoelectric activities, like those of the small intestine, are characterized by slow waves and spikes. However, unlike the small intestine, the patterns of spikes vary greatly with the species and the area of the large intestine