In 1996, Saltzman et al. introduced a modifi ­cation to the Soave technique, consisting in per­forming the entire mucosal dissection through a transanal approach as the abdominal incision was made. Their experience included 25 cases [

In 1967, Okamoto and Ueda [ 62 ] published an elegant paper, a study done with human embryos that allowed him to present his theory of the cranial- caudal migration of the neuroblast in the gastrointestinal tract. As time goes by and more research is performed, things seem to be more complex than previously thought.

Patients with Hirschsprung’s disease not only have manifestations of colonic obstruction but what makes this clinical picture different from other etiologies of colonic obstruction is the fact that proximal to the aganglionic segment, these patients frequently have a tendency to overgrow abnormal bacteria, specifi cally C. dif- fi cile , and they suffer from severe endotoxemia, a condition well known by pediatric surgeons as “Hirschsprung’s enterocolitis.” In other words,

The diagnosis of Hirschsprung’s disease is strongly suggested by the clinical symptomatol­ogy. A contrast enema reinforces the clinical sus­picion, and fi nally, the diagnosis is confi rmed by a rectal biopsy showing absent ganglion cells, the presence of hypertrophic nerves, and increased activity of acetyl cholinesterase. An abdomi­nal plain x-ray fi lm shows enormously dilated loops of bowel (Fig. ologists and experienced clinicians agree that it is extremely diffi cult to differentiate in a plain abdominal fi lm in a newborn baby a distended colon from a distended small bowel. That may be possible in adults but is almost impossible in newborn babies. However, very few neona­tal conditions give an image of such an enor­mous dilatation of loops of bowel. The next step after we see the plain abdominal x-ray fi lm is to perform a contrast enema. Characteristically, the study shows a non-dilated portion, usually

24.3 ). Most pediatric radi-

Some newborns have a very obvious, radio­logic image characteristic of Hirschsprung’s dis­ease. In others, however, the transition zone and the proximal dilated portion are not so clear, yet together with the clinical manifestations allow us to make a diagnosis of Hirschsprung’s disease (Fig. 24.2 ). When the contrast study has been done, another characteristic of these babies is their incapacity to expel the contrast material

We recognize that many times, the symptoms can be rather equivocal; in addition, sometimes the images obtained with the contrast enema may not be characteristic. Also, we had cases in which the suction rectal biopsies did not obtain good specimens. In such cases, we take a full rec­tal biopsy, which fi nalizes the diagnostic work. We are aware of the fact that many surgeons value the rectal manometry for the diagnosis of Hirschsprung’s [

with that diagnostic modality.

Despite all the advances, the fundamental basis for the diagnosis of Hirschsprung’s disease still depends on a skillful pathologic analysis and the use of hematoxylin and eosin stains, to iden­tify the presence or absence of ganglion cells and hypertrophic nerve trunks. Acetylcholinesterase (AchE) histochemistry on frozen sections and immune histochemistry for ganglion cells are useful ancillary techniques, but they do not replace the H&E methodology. Adequate sam­pling, extensive sectioning, and an experienced pathologist are the most important aspects of a good histologic diagnosis [ 88 ].

pediatric surgical community is that we should not assume that every pathologist can make the diagnosis of Hirschsprung’s disease. For instance, the diagnosis based on frozen section is reliable for certain specifi c experienced pathologists but not for others. Therefore, the surgeon must be ready to follow a different surgical strategy in the management of these patients depending on his or her surrounding circumstances. In some countries that we have visited, there are no pathologists available sometimes for several days, and there­fore, that requires a different surgical strategy. In some places, the surgeons tend to believe only in the increase of the activity of acetylcholine ester­ase rather than on the absence of ganglion cells. Most pathologists all over the world agree, like us, that the basis for the diagnosis should be the absence of ganglion cells and the presence of hypertrophic nerves.

Several other conditions are associated to hypomotility of the colon and may mimic Hirschsprung’s including hypothyroidism and effects from opiate or magnesium sulfate, transmitted from the mother.

Unfortunately, in many institutions, the term “colonic irrigation” is confused with an enema. An enema consists of the introduction of a specifi c vol­ume of a fl uid into the colon in order to provoke a bowel movement. By defi nition, patients with Hirschsprung’s disease have poor peristalsis, inca­pacity to expel fl uids, and therefore, enemas are contraindicated as they may be retained and aggra­vate the symptomatology. On the other hand, irriga­tion means the passing of a tube through the rectum, large enough to allow the expulsion of liquid stool through the lumen of the tube itself. The term “irri­gation” comes from the idea of passing, through the lumen of the tube, small volumes of saline solution, 10 mL at a time, in order to clear the lumen of the tube to allow decompression of the colon. The tube is well lubricated and is passed through the rectum, which allows an explosive decompression of most of the colon. After this fi rst episode, the nurse or the doctor passes small volumes of saline solution through the tube and keeps moving the tube back and forth and rotating it, trying to get into the pock­ets of gas and liquid stool (See Animation 24.1 showing a “Colonic Irrigation”). The benefi t of this irrigation is very obvious from the moment it is done. In fact, it may save the baby’s life. Even when this explanation of the difference between an enema and irrigation sounds obvious, we have been impressed by the frequency with which these two terms are confused even in well-reputed institutions and how often irrigations are neglected in the initial management altogether.

The main goal in the treatment of patients with Hirschsprung’s disease is to resect the agangli­onic segment and pull down normoganglionic bowel that must be anastomosed to the rectum

Traditionally, these patients received a colos­tomy at birth, usually a right transverse colos­tomy followed later in life by an abdominoperineal resection of the aganglionic segment with pull­through of the normoganglionic bowel and a third operation consisting of a colostomy closure. Subsequently, another way to approach these patients consisted in opening what is called a “leveling colostomy,” meaning to open the colos­tomy in the transition zone; later on, in a second operation, the aganglionic segment was resected and the normoganglionic colostomy site was pulled down to be connected to the rectum. This was known as a “two-stage approach.” Finally in 1980, Dr. Henry So, in Long Island, New York, published his experience with an endorectal pull­through without colostomy in neonates with Hirschsprung’s [ 89 ]; soon after, that modality of treatment was adopted by many surgeons [ 90 – 101 ]. Other modalities include a laparoscopic primary approach and, more recently, the primary transanal approach [ 30 ].