Altered intramuscular innervation and synapse formation in internal sphincter achalasia

Internal anal sphincter achalasia (IASA) is a condition with a clinical presentation similar to Hirschsprung's disease, but with the presence of ganglion cells on rectal biopsy. The diagnosis of IASA is made on anorectal manometry, which demonstrates the absence of a rectosphincteric reflux on rectal balloon inflation. In order to understand the nature of neuronal abnormalities in this condition, we performed immunohistochemistry using PGP 9.5 (a general neuronal marker) and synapsin I (a presynaptic marker) in IAS specimens from 10 patients with IASA and 8 normal controls. In the IAS of normal controls, there were many PGP 9.5 and synapsin I-positive nerve fibers. In IASA PGP 9.5-immunoreactive fibers were markedly reduced and synapsin I-positive fibers were either absent or markedly reduced. Our findings demonstrate that the IAS in achalasia patients has defective intramuscular innervation as well as defective innervation of the neuromuscular junction, thereby contributing to the motility dysfunction.     

Immunohistochemical study of peptidergic nerves in infantile hypertrophic pyloric stenosis

In the recent literature it has been noted that peptidergic nerves may play an important role in infantile hypertrophic pyloric stenosis (HPS). Specimens from 20 patients with HPS were examined by immunohistochemistry with regard to the distribution of nerve cells and nerve fibers containing enkephalin (ENK), substance P (SP), and vasoactive intestinal polypeptide (VIP). Three subpopulations of peptides containing nerve cells and fibers were fairly numerous in the control specimens, but in the patients with HPS the density of the nerve fibers was markedly reduced and occasionally absent, especially the ENK- and VIP-containing fibers. In the myenteric plexus there was neither a reduction of nerve cell bodies nor of fibers. Our findings suggest that abnormalities of peptide-containing nerve fibers or impairment of neuronal function might results in HPS.     

Achalasia of the anal sphincter

Enzyme-histotopochemical studies of parasympathetic innervation in the internal anal sphincter muscle of 73 children with anal sphincter achalasia indicated that in Hirschsprung's disease and type B neuronal intestinal dysplasia (NID) the internal sphincter displays a pattern of changes analogous to that seen in the wall of the rectum. In Hirschsprung's disease the internal sphincter is also aganglionic, and its parasympathetic fibres exhibit increased acetylcholinesterase (ACE) activity in NID there is moderately increased ACE activity, with ganglionic neurons embedded singly or in groups in the thick afferent parasympathetic fibers. The innervation defect may be confined to the sphincter, or aganglionosis of the sphincter may be associated with proximal NID. Offprint requests to: J. Welskop     

The nature of neurogenic damage to the external anal sphincter in children treated for Hirschsprung's disease

Children with faecal continence problems following surgical pull-through procedures performed for Hirschsprung's disease were investigated by concentric needle electromyographic studies of the external anal sphincter and puborectalis. The results were compared with those from a control group of children incontinent following correction of anorectal anomalies. In the Hirschsprung group the motor unit potentials in the external sphincter, but not in puborectalis, showed florid abnormalities with increased complexity and duration of the waveform, often with blocking and increased jitter, indicative of a continuing process of denervation and reinnervation. In four of the five patients with Hirschsprung's disease who were tested, pudendal nerve terminal latencies were increased, suggesting neurogenic damage to the external sphincter. Where such changes are found in children incontinent following surgery for Hirschsprung's disease, they may indicate a need for modified clinical management.The protocols used in this study were approved by the Standing Committee on Ethical Practice of the Hospital for Sick Children. Offprint requests to: S. G. Boyd     

经肛门直肠黏膜及内括约肌切除术治疗先天性巨结肠的技术要点和疗效

目的 探讨肛门内括约肌大部切除对治疗小儿先天性巨结肠的技术可行性和临床效果.方法 从2001年7月至2006年12月,对127例先天性巨结肠患儿根治术中进行内括约肌大部切除,手术时患儿年龄8 d～16岁,平均年龄0.96岁,小于3个月的33例,其中新生儿12例.术前43例(33.8%)有肠炎病史,手术方法:在齿线水平的直肠黏膜与肛管皮肤的交界处环周切开黏膜及肛门内括约肌;沿内、外括约肌之间隙向盆腔侧分离1cm后;在前壁切开直肠的肌层至黏膜下层,沿着黏膜下层向上分离直达腹膜返折水平切开肌鞘,入腹腔;在后壁沿着直肠纵肌,一直向上分离至相应的腹膜返折水平.将正常结肠拖出至肛缘水平与肛管黏膜皮肤相吻合.结果 本组127例患儿均经肛门行内括约肌和直肠后壁肌鞘切除术,目前106例患儿术后已随访1至7年,术后仅2例患儿有肠炎病史,术后肠炎发生率为1.8%,比术前明显减少(P<0.01).3例(2.7%)患儿手术后便秘,1例在外院确诊为结肠神经元发育不良症,行结肠切除手术后治愈.手术后1个月时污便的发生率37.6%,随手术后时间的延长,手术后6个月时污便下降至1.8%.肛门直肠测压结果显示:对照组肛管静息压力为(27.9±9.6)mm Hg;先天性巨结肠患儿手术前的肛管静息压力为(37.9±12.5)mm Hg,比对照组明显增高(P<0.05);手术后1、2、3、6个月肛管静息压力分别为(20.2±6.4)、(21.4±8.8)、(22.8±10.4)、(24.8±9.9)mm Hg,手术后肛管静息压力比手术前明显减低(P<0.01),术后6个月内患儿的肛管静息压力有上升的趋势,与对照组差异无统计学意义.结论 本研究结果表明经肛门内括约肌大部切除安全易行,可有效地预防小儿先天性巨结肠术后肠炎和便秘的发生.     

Long-term outcome of internal sphincter myectomy in patients with internal anal sphincter achalasia

Background  

Internal anal sphincter achalasia (IASA) is a condition with presentation similar to Hirschsprung’s disease (HD), but with the presence of ganglion cells on rectal suction biopsy (RSB). The diagnosis is made on anorectal manometry (ARM) by the absence of the rectosphincteric reflex on rectal balloon inflation. Internal sphincter myectomy (ISM) is the treatment of choice for patients with IASA. Recently, botulinum toxin has been used to treat IASA patients. The purpose of this study was to assess the long-term bowel function in patients with IASA following ISM.     

Abnormal peptidergic innervation in internal sphincter achalasia

The internal anal sphincter is morphologically derived from the circular muscle of the rectum, but marked differences have been observed in the motor activities of these two morphologically continuous structures. Immunocytochemical studies using anti-neurotransmitter antibodies (vasoactive intestinal peptide, substance P, metenkephalin, neuropeptide Y), enzyme histochemistry for acetylcholinesterase, and electron microscopy were carried out on internal sphincter specimens from 14 patients with internal sphincter achalasia, 5 normal controls, and on rectum from 4 patients with Hirschsprung's disease (HD). The various peptide-containing nerves were increased in internal sphincter achalasia compared to normal controls and patients with HD. The pathophysiology of internal sphincter achalasia appears to differ from that of HD. It is a distinct clinical entity and should be considered separate from the latter. Offprint requests to: T. Fujimoto     

Defects in peptidergic innervation in Hirschsprung's disease

Aganglionic and ganglionic intestinal specimens from 14 patients with Hirschsprung's disease were examined by immunocytochemistry. The study revealed a reduction in nerve fibers storing vasoactive intestinal peptide (VIP), substance P (SP), and a total depletion of nerves storing enkephalin and gastrin-releasing peptide in aganglionic intestine. Nerve fibers storing peptide histidine isoleucine (PHI) or neurokinin A (NKA) were also examined. It was shown that VIP coexisted with PHI and SP with NKA and that the number of nerve fibers containing these substances was markedly reduced in the smooth-muscle layers in aganglionic bowel. In the mucosa, on the other hand, the innervation was virtually unchanged. Thus, it appears that the mucosa secretory and sensory innervation is not reduced and that the defects in peptidergic innervation in Hirschsprung's disease mainly involve motor neurons. Offprint requests to: L.-T. Larsson     

肠神经畸形肠壁神经递质表达的对比研究

目的：检测先天性巨结肠症(HD)、肠神经发育不良(1ND)、肠神经元减少症(HYPG)等各类肠神经畸形(NIM)的不同肠段的一氧化氮合酶(nNOS)、血红素氧合酶-2(HO-2)和血管活性肠肽(VIP)的表达与分布，探讨它们的表达、分布差异以及对临床的指导意义。方法：使用SP免疫组织化学方法，观察12例HD、15例IND和3例HYPG患儿的不同肠段中nNOS、HO-2和VIP的分布，并将吻合口处直肠肠段与10例正常儿童结肠对比。结果：HD组中直肠的nNOS和HO-2染色阳性的纤维偶见。但VIP在黏膜下层的染色在不同病例中不尽相同；IND组直肠和扩张结肠中nNOS和VIP阳性的神经元和神经纤维有不同程度增多；HYPG组中直肠三种神经递质表达均有不同程度减少。结论：不同神经递质的表达在各类NIM中并不一致，提示HD、IND及HYPG的发病原因不完全相同。检测直肠远端的神经递质，特别是nNOS的含量和分布有助于临床鉴别各类NIM。     

Granular-cell tumorlike Schwann cell degeneration in the anal sphincter of an infant suspected of having ultrashort Hirschsprung's disease

A 19-month-old girl who had a history of constipation since birth and suspected cytomegalovirus (CMV) infection was admitted. Barium enema revealed no caliber change in the colon, anorectal manometry failed to show sphincter relaxation on rectal distension, and biopsied rectal specimens contained ganglion cells. She underwent rectal myectomy, after which her symptoms improved significantly. Morphologic studies, including electron micrographs of the muscle, demonstrated nerve plexuses with degenerative Schwann cells containing abundant eosinphilic cytoplasmic granules that resembled those of a granular-cell tumor. Granular-cell tumorlike change of the plexus is an unprecedented finding in any form of Hirschsprung's disease or its allied disorders, but appears to have been responsible for her symptoms. CMV as a causative agent is also discussed with a review of the literature.     

Thickening of the internal anal sphincter in idiopathic constipation in children

Thickening of the internal anal sphincter (IAS) is observed in chronic idiopathic constipation (IC) and solitary rectal ulcer syndrome (SRUS), where it has been correlated with the presence and severity of rectal intussusception. Alternatively, thickened IAS may be a feature of the obstructed megarectum in a similar way to the hypertrophy of bladder neck seen in dyssynergic bladders. The aim of this study was to investigate the significance of thickening of the IAS in children with chronic IC and to determine any association between the thickened IAS and anorectal manometry findings and patient's symptoms. A total of 144 children were admitted for investigations and treatment of chronic IC and evaluated prospectively between April 2001 and April 2003. IAS thickness was measured by endosonography using B&K axial endosonic probe type 1850 with a 10-MHz rotating transducer. The thickness of IAS was measured at 3, 6, and 9 o'clock, and the mean value of the three measurements was used for analysis. Functional assessment was done by anorectal manometry pressure studies under ketamine anaesthesia. A validated symptom score (SS) was used to assess the severity of symptoms. The sum of SS ranged between 0 and 65. Spearman's rho two-tailed test was used to correlate the thickness of IAS with patients' symptoms and anorectal manometry findings. Results were expressed as median and range and p-value of less than 0.05 was considered significant. Of 144 children, 84 were boys, median age 8.1 years (range 3.1-15). Soiling was present in 137 (94%) patients, delay in defecation in 132 (91%), and a palpable megarectum on abdominal examination in 117 (80%). The median duration of symptoms and duration of laxative treatment were 4 years (range 0.3-14.5) and 3.3 years (0.2-13.5), respectively. The average severity score for soiling, delay in defecation, palpable megarectum, and the total SS were 8 (range 0-10), 5 (0-10), 2 (0-12), and 33 (11-51), respectively. The median thickness of IAS was 0.9 mm (range 0.3-2.8) and the median resting anal sphincter pressure was 54 mmHg (19-107). The median amplitudes of rectal and anal sphincter contraction were 3 mmHg (1-25) and 9 mmHg (1-35), respectively. The thickness of IAS correlated significantly with total symptom severity score (r=0.31, p=0.0001), soiling score (r=0.28, p=0.001), megarectum score on abdominal palpation (r=0.29, p=0.001), size of megarectum on manometry (r=0.36, p=0.0001), amplitude of rectal contraction (r=0.23, p=0.007), and age of patient (r=0.55, p=0.0001). There was also a significant correlation between the amplitude of rectal and anal sphincter contraction (r=0.32, p=0.0001). There was no correlation between thickness of IAS and resting anal sphincter pressure and amplitude of anal sphincter contraction on anorectal manometry study. A total of 24 children had myectomy of thickened and overactive IAS in addition to the medical treatment of their chronic IC. The histology examination of myectomy specimen with eosin and haematoxylin staining and histochemical acetylcholine esterase staining showed smooth muscle fibres and ganglion cells. Thickening of IAS correlates significantly with duration and severity of symptoms, size of megarectum, and amplitude of rectal contraction. The pathogenesis is secondary to the continuous presence of faeces in the rectum, resulting in chronic abnormal stimulus to the IAS, which leads to hypertrophic changes in the rectum wall and IAS.     

犬神经性膀胱功能障碍时神经肽类递质的分布变化

目的：观察犬神经性膀胱功能障碍时血管活性肠肽（VIP），酪神经肽（神经肽Y，NPY）和P物质（SP）在膀胱中分布的变化。探讨神经肽同神经源性膀胱功能障碍的关系。方法：采用横断犬腰骶交界处脊髓和破坏浓犬骶段脊髓的方法，建立骶上型（n=3)和骶下型（n=4)神经性膀胱动物模型，另设非脊髓损伤组（n=3)作为对照，采用免疫组织化学的方法检测膀胱颈和膀胱体中VIP、NPY和SP的分布，结果：骶上型组，膀胱体部肌层VIP分分布高于正常组；无论是在膀胱体部，还是在膀胱底部，两神经性膀胱模型组的NPY分布明显降低。SP的分布变化与NPY相似。结论：在神经源性膀胱功能障碍中，膀胱肌层的VIP、NPY和SP分布会发生变化。骶髓是调节膀胱VIP合成或／和释放的中枢，调节NPY和SP合成／释放的中枢位于骶上。另外VIP是协调膀胱和膀胱体活动的递质。     

先天性巨结肠与巨结肠同源病的Ret蛋白免疫组织化学研究

目的了解Ret蛋白在先天性巨结肠和具结肠同源病肠组织中的表达,并进一步研究Ret蛋白在先天性巨结肠和巨结肠同源病发病中的作用。方法采用鼠抗人Ret单克隆抗体通过免疫组化SABC法对15例先天性巨结肠,11例巨结肠同源病肠组织Ret蛋白的表达进行研究,10例正常结肠组织作对照。结果Ret蛋白在先天性巨结肠和巨结肠同源病的扩张段,对照组均呈现阳性反应（P〉0．05）,在先天性巨结肠狭窄段大多数表现为阴性反应,极少数出现阳性反应,而巨结肠同源病狭窄段可见Ret免疫反应蛋白阳性细胞,而且偶见巨大的阳性细胞;先天性巨结肠狭窄段分别与巨结肠同源病狭窄段和对照组比较均有统计学意义（P〈0．001）。结论Ret蛋白对先天性巨结肠的发生有重要作用,而与巨结肠同源病的发生无明确关系。     

The treatment of internal anal sphincter achalasia with botulinum toxin

Internal anal sphincter (IAS) achalasia is a disorder of defecation in which the IAS fails to relax. Botulinum toxin (BT), which has been successfully used to relax the anal and lower esophageal sphincters, was injected twice into the IAS of one adolescent and three infants with manometric, radiologic, and in 2 cases histochemical diagnosis of anal achalasia; in the adolescent a third injection was necessary. Spontaneous defecation was achieved in all patients following the second injection. In one case a diagnosis of short-segment Hirschsprung's disease was obtained after the second injection. Local infiltration of BT into the IAS proved effective in the treatment of IAS achalasia. Double-blind studies and longer follow-up periods are needed to better evaluate these preliminary results and define the limits of this promising therapy. Accepted: 16 November 2000     

The early diagnosis of Hirschsprung's disease

The majority of cases of aganglionosis present and can be diagnosed in the neonatal period. Enterocolitis is a common and fatal complication so that early diagnosis is important. The plain films and enema features of 47 cases diagnosed in the neonatal period were examined. Except when a bowel wash out had been given, all these cases showed obstructive fluid levels in the plain films and the common type of short segment aganglionosis gave an egg on end appearance of low small bowel obstruction in the inverted lateral view. The classical enema features take time to develop and the narrowed aganglio wic area is not always obvious but can be shown by a careful technique of slow filling with delayed films. A high degree of accuracy was obtained except in the cases of preliminary lavage, enterocolitis and meconium plug. To make an early correct diagnosis, it is important to have close correlation between clinicians, radiologists, and pathologists.     

The expression and significance of calretinin in the colon of patients with Hirschsprung's disease

目的 本研究应用免疫组织化学染色方法,观察对照组肠壁、先天性巨结肠症(Hirschsprung's disease,HD)患儿有神经节细胞段和无神经节细胞段肠壁神经组织中钙视网膜蛋白(Calretinin,CR)的表达结果,目的在于了解HD的病理生理改变以及寻找诊断先天性巨结肠的简便有效的方法.方法 收集苏州大学附属儿童医院小儿外科2005至2008年手术切除HD标本54例,包括HD扩张段与痉挛段.以15例年龄与之相符的无HD患儿的手术切除结肠标本作为对照组.分别对HD痉挛段、扩张段、对照组肠壁组织切片进行CR的免疫组织化学染色和HE染色,计算机成像系统照相存盘,用图像分析软件(Image-Pro-Plus)分别判定CR在HD扩张段与痉挛段神经丛中阳性染色面积百分比.所得数据用SPSS 12.0统计软件包进行处理分析.结果 ①无论是HE或免疫组化染色HD的扩张段神经节细胞皆存在,肌层神经纤维有不同程度的排列改变,神经节细胞大小不等;痉挛段均未见神经节细胞;②在正常结肠及HD扩张段肠壁免疫组化染色可见钙视网膜蛋白在肌间及黏膜下神经丛中对神经节细胞呈强阳性表达,神经纤维也呈阳性反应;而HD痉挛段肠壁的免疫组化染色则可见钙视网膜蛋白在肌间神经丛及黏膜下神经丛大多表达阴性(90.7％),仅少量呈弱阳性表达(9.3％);③定量分析:CR分别在HD痉挛段之间神经丛中阳性染色面积百分率(0.00665±().00387)与其在HD扩张段神经丛中阳性染色面积百分率(0.26483±0.14626)存在差异,有显著统计学意义(P＜0.01).结论 钙视网膜蛋白免疫组化染色可很好的显示正常结肠及HD扩张段肠壁的神经节细胞及神经纤维,而在HD痉挛段该指标免疫组化染色结果呈阴性或弱阳性表达.钙视网膜蛋白可能作为诊断HD的神经标志物之一.     

Colorectal resection and anal anastomosis with an intraluminal stapler in Hirschsprung's disease

Twenty patients aged 5 months — 4 years (mean 14 months) with Hirschsprung's disease were operated upon. In all cases a pull-through resection and stapled circular coloanal anastomosis was performed, in 11 with a single-stapling technique and in 9 with double-stapling. Isopaque rectography 4–10 days postoperatively showed an intact anastomosis in all 20 patients, i. e., there were no clinical or subclinical leaks. On palpation 4–6 weeks post-operatively, there were signs of stenosis in 4 patients. However, no. 9–11 Hegar dilators passed easily and there was no residual stenosis at follow-up 3 months after surgery. The technique can be recommended in children over 6 months of age.     

Botulinum toxin for the treatment of chronic constipation in children with internal anal sphincter dysfunction

Internal anal sphincter (IAS) dysfunction is a cause of refractory constipation in children. The goal of this study was to determine whether intrasphincteric injection of botulinum toxin is effective in the treatment of constipation in pediatric patients with IAS dysfunction. A retrospective review was performed of 24 pediatric patients with intractable constipation. All patients had abnormal anorectal manometry, with either elevated IAS resting pressure (> or =100 mm Hg) or an absent or diminished rectoanal inhibitory reflex. Patients with Hirschsprung's disease were excluded. All patients underwent botox injection into the IAS and were followed for a minimum of 6 months. Of 24 patients, 22 experienced significant improvement in their constipation lasting greater than 2 weeks. The duration of effect was variable, with 12 patients demonstrating benefit lasting at least 6 months. Transient postoperative incontinence occurred in five patients. Intrasphincteric injection of botox is a safe and effective treatment for intractable constipation in children with IAS dysfunction.     

Early onset of cecal perforation in neonatal,recto-sigmoid type Hirschsprung's disease

Hirschsprung's disease has been considered to cause intestinal perforation in rare cases. Even if a perforation occurs, the majority of cases are associated with the long-segment or total colonic type. Our case developed the perforation in the neonatal period in spite of being of the recto-sigmoidal type, and it affected the cecum. We do not have a good explanation for this condition. However, the pathological examination of the specimens of the perforated cecum revealed some necrosis (ulceration, subcutaneous hemorrhage, congestion and severe edema) which was considered to be caused by ischemia, secondary to a localized vascular accident in the wall of the distended intestine.