Enfermedad de Hirschprungo

Megacolon Congenito

5to C

Que es?????

• Consiste en una ausencia de células • Ganglionares• Ganglios nerviosos

• En la pared− Muscular − Submucosa

Porque??

• Detención en la migración caudal de las células procedentes de la cresta neural antes de llegar al ano• Desarrollo embrionario

Incidencia

• 1 de cada 5,000• 70% a 80%

• Masculinos• Menos frecuente en la

raza negra• Antecedente +

• Mayor riesgo de padecerla

• Malformaciones agregadas• 25% de los casos con

antecedes familiares• 10% no familiar (sin

antecedentes)

Factores Genéticos

• Se descubrió una paciente femenina con aganglionosis total del colon

• Sindrome de Zuelzer-Wilson

• portaba una deleción en el cromosoma • 10:46,XX de q110.11.21-q21.2

Tres genes

• Identificados en el hombre

1. Gen de RET – Cromosoma 10

• Autosómicos dominante

2. Gen EDNRB– Gen del receptor de la

endotelina B– Cromosoma 13

– Autosómicos Recesivo

3. Gen EDN3• Gen de endotelina 3

• Cromosoma 20− Autosómicos recesivo

Fisiopatología

• Intestino• Falta de propagación

de las ondas de propulsión

• Esfínter anal interno• Relajación anormal• Ausencia de la

relajación

Fisiopatología

Intestino Esfínter anal Interno

Falta de ondas peristalticas

Relajación anormalO ausencia de la

relajación

AganlionosisHipoganglionosis

Disganglionosi

Cuadro Clinico

• 3 Puntos Cardinales1. Ausencia de evacuacion en las primeras

24 hrs de vida2. Distension Abdominal3. Vomito

Examen Rectal

• Con sonda rectal, termometro o lavados

• Induce a la salida explosiva de heces liquidas y gas sospechoso a enterocolitis

• Se nota hipertonía del esfínter rectal y casi siempre esta vacío

• Se ha visto que la ENTEROCOLITIS se presenta en un 12% a 58% de los pacientes con megacolon congénito

Enterocolitis

• Hipotesis Etiologicas1. Estasis fecal

• Isquemia en mucosa• Invasion y traslocacion

de bacteriana.2. Alteracion de las de la

composicion de la mucina y mecanismos de defensa de la mucosa

3. Aumento de la actividad de la prostaglandina E1 y la infeccion por Clostridium difficile

Forma grave de enterocolitis

• Megacolon toxico• Caracterizado por:

1. Fiebre2. Vomito teñido de bilis3. Diarrea explosiva4. Distensión abdominal5. Deshidratación6. Choque

Diagnostico

• Radiologico• Radiografia

abdominal• Posicion Supina y

verticla• Muestran niveles

Hidroaereos en colon

Hallazgo tipico

Imagen transoperatoria

Ecografia que muestra EH ultra corta

EH con segmento largosíndrome de Zuelzer-Wilson

Electromanometria Rectal

• Precisión diagnostica• 85%

• Normalmente• Se produce relajacion

del esfínter anal interno• EH

• Muestran cambios característicos durante el estimulo

• En la presión del conducto anal

• Parte inferior del recto

Biopsia Rectal

• Se toman muestras de • 2, 3, 5 cm

• Muestra optima• 3.5 cm de

diametro• Incluye submucosa

Tinción de hematoxilina y eosina

Examen histoquimico

Celulas ganglionares gigantes y heterotopicas en el plexo submucoso, en un paciente con displasia neuronal intestinal

Tratamiento

• Descompresión

1. Instalación de una sonda nasogastrica.2. Vaciamiento repetido del recto con sonda

rectales e irrigaciones.− Después de hacer todos los métodos diagnósticos

– Se procede a establecer un estoma, si es necesario.

Tratamiento

• Colostomía• Antes de realizarla

es necesario1. Lavado intestinal2. Administracion de

antibioticos 30 minutos antes de la operación

3. Instalación de una sonda ureteral

Procedimientos Definitivos

• Técnica de Swenson

• For Swenson’s pull-through operation the patient is positioned on the operating table to provide simultaneous exposure of the perineum and abdomen. The pelvis is allowed to drop back over the lower end of the table and the legs are strapped over sandbags. A Foley catheter is inserted into the bladder. The abdomen is opened via a paramedian incision. Some surgeons prefer a Pfannenstiel incision when performing a Swenson’s pull-through operation in the neonate. Extramucosal biopsies are taken at intervals along the antimesenteric border and assessed by frozensection to determine the level of ganglionatedbowel. The sigmoid colon is mobilized by dividingthe sigmoid vessels and retaining the marginalvessels.It may be necessary to mobilize the splenic flexureto obtain adequate length. The proximal level ofresection above the ganglionated level, previouslydetermined by frozen section, is selected and the bowel is divided between intestinal clamps or staples. The peritoneum is divided around its lateral andanterior reflection from the rectum, exposing themuscle coat of the rectum.At this point, the bowel isdivided at the rectosigmoid junction and removed.Dissection extends around the rectum, keeping veryclose to the bowel wall. It is essential to maintain thedissection close to the muscular wall in order to preventdamage to the pelvic splanchnic innervation.All

vessels are electro-coagulated under direct vision. Sufficient tension-free length is obtained by dividing the inferior mesenteric pedicle, carefully preserving the marginal vessels. Dissection is carried down to the level of the external sphincter posteriorly and laterally, but does not extend as deeply anteriorly,leaving around 1.5 cm of intact rectal wall abutting against the vagina or urethra. The mobilized rectum is intussuscepted through the anus by passing a curved clamp or a Babcock forceps through the anal canal; an assistant places the closed rectal stump within the jaws of the clamp. When the dissection has been completed, it should

be possible to evert the anal canal completely when traction is applied to the rectum.An incision is made anteriorly through the rectal wall about 1 cm from the dentate line, extending halfway through the rectal circumference.A clamp is inserted through this incision to grasp multiple sutures placed through the cut end of the proximal colon. An outer layer of interrupted 4-0 absorbable sutures is placed through the cut muscular edge of the rectum and the muscular wall of the pull-through colon.When the outer layer has been completed, the proximal bowel is opened and an inner layer of interrupted 4-0 absorbable suturesis placed.When anastomosis is completed, the sutures are cut, allowing the anastomosis to retractwithin the anus.

Técnica

Procedimientos definitivo

• Técnica de Duhamel-Grob

Tecnica

The advantage of the Duhamel pull-through is that very little manipulation of the rectum is performed anteriorly thus avoiding injury to the genitourinary innervation. The rectum is divided and closed just above the peritoneal reflection. The redundant aganglionic bowel is resected. The retrorectal space is created by blunt dissection down to the pelvic floor. The posterior rectal wall is incised 1.5 to 2 cm above the dentate line and sponge holding forceps is inserted into the retrorectal space and ganglionic bowel pulled through. The anterior half of the pulledthrough ganglionic bowel is anastomosed to the posterior wall of the aganglionic rectum and remainder of the colo-rectal anastomosis completed by approximating the aganglionic rectum to the posterior wall of the pulled-through ganglionic bowel. Finally an extra long automatic stapling device is used to complete the side to side anastomosis between the aganglionic rectum and the ganglionic pulled-through bowel. Some surgeons complete the side to side anastomosis prior to closing the rectal stump, thereby preventing any residual septum.

Procedimientos definitivos

• Descenso endorectal

Técnica

In Soave or endorectal pull-through the first steps of the operation are similar to those described for Swenson’s or Duhamel operation. The colon is mobilized and resected about 4 cm above the peritoneal reflection. The endorectal dissection begins 2 cm below the peritoneal reflection. The seromuscular layer is incised circumferentially and the mucosal-submucosal tube is freed distally. The mucosal dissection iscontinued distally to the level of the dentate line. Themucosa is incised circumferentially 1 cm above thedentate line. A Kelly clamp is inserted from belowand the ganglionic bowel is pulled through.Coloanalanastomosis is completed using 4/0 absorbable sutures.

Procedimientos definitivos

• Resección anterior según Rehbein

Técnica

Rehbein’s technique differs from the Swenson’s procedure,in that the anastomosis is a low, anterior colorectal anastomosis. In this procedure, 3 to 5 cm of the terminal aganglionic rectum is left behind,which is anastomosed to the ganglionic bowel.

Bibliografía

• CIRUGIA PEDIATRIA ASCHRAFT Murphy, Sharp, Sigalet, Snyder

• SPRINGER SURGERY ATLAS SERIES Series Editors: J. S. P. Lumley · J. R. Siewert