740 



HERNIA. 



that the neck shall be so contracted that in the 

 new occurrence of hernia an additional portion 

 of peritoneum may be detruded, and then the 

 sac must present the shape of an hour-glass, 

 narrow in the centre and broad at either end : 

 sometimes two, three, or more of these succes- 

 sive protrusions take place, and then the sac 

 is divided into so many sacculi with incomplete 

 intercepts or partitions between them. Or one 

 portion of peritoneum may be forced within 

 another, so that the intestine is actually in- 

 cluded within a double sac. This last is a 

 curious and very uncommon occurrence. On 

 the other hand the neck of a hernial sac may 

 suffer distension. In very old ruptures that 

 have become irreducible or from any other 

 cause been long down, the neck of the sac 

 sometimes becomes wonderfully dilated, and the 

 portion of intestine immediately passing through 

 it scarcely subjected to the slightest pressure. 



There is one form of hernia, the chief 

 peculiarity of which lies in the nature of its 

 peritoneal investment, for, correctly speaking, it 

 possesses no proper sac. It is the hernia con- 

 genita,* a species of rupture which occurs in 

 very young infants, and sometimes, under 

 peculiar circumstances, in persons of a more 

 advanced age also. 



During the early periods of foetal existence 

 the testes do not occupy that situation which 

 they possess in after life. They are placed 

 within the abdomen, above the pelvis, which at 

 this time is so small and imperfectly developed 

 that many of the viscera lodged within it after- 

 wards, seem now to lie within the belly. They 

 are just below the kidneys, in front of the psoas 

 muscle at each side, and possess, like other 

 viscera, an investiture of peritoneum, which is 

 afterwards to be the tunica vaginalis testis. 

 About the sixth month, or perhaps the seventh 

 or even later, (for it observes no exact rule in 

 this respect,) the testis begins to descend, not 

 gliding behind the peritoneum, but preserving its 

 own investing coat until it comes to the internal 

 abdominal ring, where it pushes a process of 

 peritoneum out before it, just as an intestine 

 would do in the production of a hernial sac. 

 This is afterwards to become the tunica vaginalis 

 scroti. The testicle then passes on through the 

 inguinal canal, through the external ring,f and 

 fit-ally drops into the scrotum. After some 

 time the canal of communication with the cavity 

 of the abdomen begins to contract and close, 

 and if the usual process goes on healthily and 

 without interruption, very shortly a complete 

 obliteration takes place, and the testis is sepa- 

 rated from the abdomen perfectly and for ever. 

 The time at which this is accomplished is ex- 

 tremely uncertain : sometimes it is perfect at 

 birth ; in other cases the canal is more or less 

 open, and then, if the infant cries or struggles, 

 a portion of the contents of the abdomen is 

 protruded into the cavity of the tunica vaginalis, 



* Hunter's Animal (Economy. 



t See some observations on the descent of the 

 testicle by the late Professor Todd, of Dublin, in the 

 1st vol. Dublin Hospital Reports. See also Key's 

 Observations in Surgery, p. 226. 



and the hernia congenita is formed. If any part 

 of the above-mentioned process is interrupted 

 or postponed, it will occasion some variety. 

 Thus the tunica vaginalis may not exhibit its 

 usual disposition to close and become obliter- 

 ated at its neck, and then for a length of time 

 the patient is exposed to all the inconvenience 

 and hazard of the descent of a hernia: sometimes 

 the testicle does not come down until a much 

 later period, a circumstance that is often occa- 

 sioned by the gland contracting adhesions with 

 some adjacent viscus in its passage, and may be 

 attended with the additional inconvenience of 

 drawing down such viscus along with it. The 

 surgeon should also be aware of the possibility 

 of the protrusion of another portion of perito- 

 neum into the open tunica vaginalis, and thus a 

 mixed case may arise of a congenital containing 

 within it a proper sacculated hernia. 



The congenital rupture, then, has no proper 

 sac, but is lodged within the tunica vaginalis in 

 close apposition with the testis r hence many 

 of its peculiarities can be explained. It is 

 obviously the only kind of hernia in which an 

 adhesion can exist between the testicle and the 

 protruded viscus, and it is also evident that the 

 testis does not bear the same relation to the 

 protruded viscus in this that it does in cases of 

 ordinary rupture. Here it is higher up, and 

 seems to be more mixed and identified with the 

 other contents; the entire tumour is more even 

 and firm, the protruded parts are less easily 

 felt and distinguished; and Hesselbach states 

 that when strangulation is present, the sac is 

 every where equally tense, and the testis cannot 

 be felt at all. In very young infants a small 

 quantity of fluid is often present along with the 

 intestine in the tunica vaginalis : it disappears 

 when the child is placed in the recumbent posi- 

 tion, and does not add to the difficulty or im- 

 portance of the case. It has been stated that 

 the tunica vaginalis has a natural tendency to 

 become closed at its neck, and therefore is it 

 more likely to thicken and diminish in capacity 

 in this situation so as to form a band round the 

 protruded viscus. Pott* was of opinion that 

 congenital hernia was more subject to be con- 

 stricted at the neck of the sac than any other : 

 Wilmer stated that out of five cases of congen- 

 ital hernia on which he operated, three were 

 strangulated at the neck of the sac; and Saudi- 

 fort and others maintained the same doctrine. 

 Scarpaf thought that every displaced portion 

 of peritoneum possessed the same tendency to 

 contraction, and advanced it as a reason why 

 stricture in the neck of a hernial sac should be 

 more frequent in all kinds of hernia than is 

 generally supposed. It is not easy to place 

 implicit reliance on this latter opinion, because 

 the neck of the common hernial sac when once 

 formed is never again completely closed ; but 

 with respect to congenital hernia the observa- 

 tion appears to be equally correct and im- 

 portant. 



ScarpaJ describes a form of hernia which may 



* Pott, op. citat. p. 184. 



t Page 131. 



$ Op. citat. p. 205 et seq. 



