Modification of Parks Classification of Cryptoglandular Anal Fistula

BACKGROUND

The Parks classification has been used for the classification of anal fistula for several years, but it does not allow for risk factors for failure after surgery.

OBJECTIVE

This study aimed to describe a modification of the Parks classification of anal fistula and examine its predictive validity in the assessment of the outcome of anal fistula in terms of failure of healing and fecal incontinence.

DESIGN

This is a retrospective review of a prospective database.

SETTING

This study was conducted in the Colorectal Surgery Unit, Mansoura University Hospitals.

PATIENTS

Adult patients with anal fistula who underwent surgery were included.

INTERVENTIONS

Five risk factors for failure after fistula surgery were identified from the literature and were examined by multivariate analysis of our patients. Four risk factors proved to be significant independent predictors of failure: secondary extensions, horseshoe fistula, previous fistula surgery, and anterior anal fistula in women. We modified the Parks classification by dividing the transsphincteric type into high and low and by grouping supra- and extrasphincteric anal fistulas into 1 group. The first 3 stages were subdivided according to the absence or presence of predictors of failure.

MAIN OUTCOME MEASURES

The primary outcome measured was the validity of the modified Parks classification with regard to the rates of failure and fecal incontinence after surgical treatment of each stage of anal fistula.

RESULTS

A total of 665 patients with cryptoglandular anal fistula were included. Failure rates increased from 2.3% (95% CI, 0.9%-4.7%), to 17.4% (95% CI, 10.8%-25.9%), 19.5% (95% CI, 15%-24.6%), and 30.7% (95% CI, 9.1%-61.4%) across the 4 stages. The area under the receiver operating characteristic curve was 0.90 (95% CI, 0.85-0.94) indicating the strong discriminative ability of the final multivariable predictive model. The increase in failure and incontinence rates across the fistula stages was significant.

LIMITATIONS

This is a retrospective, single-center study.

CONCLUSION

Inclusion of predictors of poor outcome into the modified classification helped differentiate simple and complex fistulas within each stage and between the different stages, which can help in assessment and decision making for anal fistula. See Video Abstract at http://links.lww.com/DCR/B441.

MODIFICACIN DE LA CLASIFICACIN DE PARKS DE LA FSTULA ANAL CRIPTOGLANDULAR

ANTECEDENTES:La clasificación de Parks se ha utilizado para la clasificación de la fístula anal durante varios años, sin embargo, no tuvo en cuenta los factores de riesgo de fracaso después de la cirugía.OBJETIVO:Describir una modificación de la clasificación de Parks de fístula anal y examinar su validez predictiva en la evaluación de los resultados de la fístula anal en términos de fracaso de la cicatrización e incontinencia fecal.DISEÑO:Revisión retrospectiva de la base de datos prospectiva.AJUSTE:Unidad de Cirugía Colorrectal, Hospital Universitario de Mansoura.PACIENTES:Pacientes adultos con fístula anal intervenidos quirúgicamente.INTERVENCIONES:Se identificaron cinco factores de riesgo de fracaso después de la cirugía de fístula de la literatura y se examinaron mediante análisis multivariante de nuestros pacientes. Cuatro factores de riesgo demostraron ser importantes predictores independientes de fracaso: extensiones secundarias, fístula en herradura, cirugía de fístula previa y fístula anal anterior en mujeres. Modificamos la clasificación de Parks dividiendo el tipo transesfinteriano en alto y bajo y agrupando la fístula anal supraesfinteriana y extraesfinteriana en un grupo. Las tres primeras etapas se subdividieron según la ausencia o presencia de predictores de fracaso.PRINCIPALES MEDIDAS DE RESULTADO:Validez de la clasificación de Parks modificada con respecto a las tasas de fracaso e incontinencia fecal después del tratamiento quirúrgico de cada etapa de la fístula anal.RESULTADOS:Se incluyeron 665 pacientes con fístula anal criptoglandular. Las tasas de fracaso aumentaron del 2,3% (IC del 95%: 0,9-4,7%), al 17,4% (IC del 95%: 10,8 al 25,9%), 19,5% (IC del 95%: 15-24,6%) y 30,7% (95% IC: 9,1- 61,4%) en las cuatro etapas. El área bajo la curva característica operativa del receptor fue 0,90 (IC del 95%: 0,85-0,94), lo que indica una fuerte capacidad discriminativa del modelo predictivo multivariable final. El aumento en las tasas de fracaso e incontinencia en las etapas de la fístula fue significativo.LIMITACIONES:Estudio retrospectivo, unicéntrico.CONCLUSIÓN:La inclusión de predictores de mal resultado en la clasificación modificada ayudó a diferenciar las fístulas simples y complejas dentro de cada etapa y entre las diferentes etapas, lo que puede ayudar en la evaluación y toma de decisiones para la fístula anal. Consulte Video Resumen en http://links.lww.com/DCR/B441.

Perianal fistulas

Perianal fistulas are a chronic, debilitating disease that requires lifelong monitoring and, potentially, lifelong treatment. Lesions are characterized by ulcerations with draining fistulous tracts around the anal region. Most dogs experience significant pain and discomfort with this condition. Bacterial infections are a frequent secondary problem. Definitive diagnosis is based on clinical signs, signalment, history, and a thorough examination. The most successful treatment is immunomodulatory therapy (cyclosporine with or without ketoconazole and topical tacrolimus). Perianal fistulas can be difficult to treat, frustrating both veterinarians and owners.

Perirenal expanding haematoma in a cat

A four-year-old, entire male domestic cat was referred for assessment of a large abdominal mass of three-weeks duration. Diagnostic imaging suggested the presence of either splenic neoplasia, an abdominal abscess or haematoma. A coeliotomy was performed and an enlarged, irregular mass, including the left kidney and adrenal gland, was identified. The mass was removed, requiring a left adrenalo-uretero-nephrectomy. The aorta was accidentally punctured during the procedure, resulting in paraplegia. Given a poor prognosis, the owners decided to have the cat euthanased. Histological examination of the mass was characteristic of a chronic expanding haematoma.

Evaluation of the Effect of Two Dose Rates of Cyclosporine on the Severity of Perianal Fistulae Lesions and Associated Clinical Signs in Dogs

OBJECTIVE

To investigate the effect of cyclosporine (2 or 5 mg/kg every 24 hours) on perianal fistulae (PAF) lesions.

STUDY DESIGN

Blinded randomized, prospective trial.

ANIMALS

Dogs (n = 20) with perianal fistulae.

METHODS

Dogs were randomly assigned to administration of either 2 mg/kg (n = 10) or 5 mg/kg (n=10) of cyclosporine orally every 24 hours for 8 weeks. Lesion surface area was measured, lesion severity was graded using a visual analog scale, and the presence and severity of clinical signs recorded every 2 weeks.

RESULTS

Lesion variables were significantly reduced in both groups after 8 weeks and owners also reported a reduction in clinical sign severity. The 5 mg/kg dose rate significantly accelerated lesion resolution compared with 2 mg/kg. In the 2 mg/kg group, 20% of dogs had complete resolution of clinical signs and 10% had resolution of lesions. In the 5 mg/kg group, 40% of dogs had complete resolution of clinical signs and 60% had resolution of lesions.

CONCLUSIONS

A dose rate of 5 mg/kg every 24 hours was more effective at reducing the surface area and severity of PAF lesions than 2 mg/kg every 24 hours but less effective at resolving PAF lesions than previous studies using dose rates > or =5 mg/kg every 12 hours.

CLINICAL RELEVANCE

Cyclosporine at 5 mg/kg every 24 hours may be useful for the palliation of PAF lesions.

Protein expression of Mdm2 and p53 in hyperplastic and neoplastic lesions of the canine circumanal gland

Hyperplastic and neoplastic lesions of the circumanal gland in dogs were examined immunohistochemically for nuclear expression of Mdm2 and p53 proteins. Mdm2 nuclear labelling was detected in 64.3% of hyperplastic lesions and 70.7% of adenomas, the immunolabelling being stronger in the latter. Mdm2 reactivity in reserve-like cells in adenomas showed wide variation, the immunoreactive cells ranging from 4 to 80%. No reactivity was shown in 81.9% of adenocarcinomas. In contrast to Mdm2 reactivity, each of 14 hyperplastic lesions and 11 adenocarcinomas, and 60 of 65 adenomas (92.3%) failed to show nuclear p53 reactivity. These results suggest that increased expression of Mdm2 is an early event in circumanal gland tumorigenesis, and may be present in the absence of nuclear p53 protein accumulation.

[A Dutchman from Mali with a perianal ulcer caused by cutaneous amoebiasis]

A 66-year-old Dutchman, living in Mali, presented with an extensive progressive perianal ulcer despite local and antibiotic treatment. Microscopic examination of the stool revealed Entamoeba histolytica/dispar cysts and phagocytosing trophozoites were seen in fresh scrapings of the ulcer, a diagnostic feature of infection with E. histolytica. The diagnosis was cutaneous amoebiasis and the patient was effectively treated with metronidazole and local debridements. Primary cutaneous amoebiasis is a rare disease. Diagnosis and treatment are relatively simple but lack of familiarity with the disease may lead to misdiagnosis or diagnosis at a late stage ofthe infection.

Immunohistochemical Detection of Growth Hormone (GH) in Canine Hepatoid Gland Tumors

The aim of this study was to detect immunohistochemically means growth hormone (GH) in 24 hepatoid gland adenomas and 5 hepatoid gland carcinomas and to compare the difference of immunoreactivity between types of tumors. The tumors were classified according to the WHO standards. Tissue sections which were prepared from formalin-fixed, paraffin wax-embedded tissues from 25 male and 4 female dogs were carried out immunostaining using polyclonal primary anti-hGH and EnVision method. Of 24 hepatoid gland adenomas (perianal gland adenomas) 23 (95.8%) were positive. All 5 hepatoid gland carcinomas (perianal gland carcinomas) were positive. No statistically significant differences in percentage of labelled cells between malignant and benign tumors were seen. The present demonstration of GH in hepatoid gland tumors adds new data on GH in extra-pituitary tissues and hormon-dependent tumors.

Emergence of perianal fistulizing disease in the SAMP1/YitFc mouse, a spontaneous model of chronic ileitis

BACKGROUND & AIMS

SAMP1/Yit mice spontaneously develop chronic terminal ileitis, reminiscent of the human disease described by Crohn et al. in 1932. Several new phenotypic features have appeared in our colony after more than 20 generations of brother-sister mating. In this report, we describe the distinguishing features of the SAMP1/YitFc substrain at the University of Virginia, compared with the Japanese SAMP1/Yit parental strain.

METHODS

A colony of SAMP1/Yit mice was established at the University of Virginia in 1996, from 2 breeding pairs obtained from Japan. A systematic characterization of their phenotypic and immunologic characteristics was performed at 4, 10, 40, and more than 60 weeks of age.

RESULTS

The following differences were observed: (1) SAMP1/YitFc mice displayed established ileitis as early as 10 weeks of age, (2) the incidence of skin lesions inversely correlated with the occurrence of intestinal inflammation, (3) mice develop chronic ileitis with prominent muscular hypertrophy and focal collagen deposition in inflamed segments, (4) mesenteric lymph node lymphocytes acquired an activated phenotype coincident with disease progression, (5) high interferon-gamma production was detected by 4 weeks of age and preceded the onset of ileitis, and (6) a subgroup of mice (approximately 5%) developed perianal disease with ulceration and fistulae.

CONCLUSIONS

The SAMP1/YitFc substrain exhibits unique characteristics when compared with the original Japanese strain. Of particular interest is the emergence of perianal fistulizing disease, to our knowledge the first report of such occurrence in an animal model of inflammatory bowel disease.

Randomized controlled trial of cyclosporine for treatment of perianal fistulas in dogs

OBJECTIVE

To evaluate efficacy of cyclosporine for treatment of perianal fistulas in dogs.

DESIGN

Randomized, controlled trial.

ANIMALS

20 German Shepherd Dogs with naturally developing perianal fistulas.

PROCEDURE

10 dogs were treated with cyclosporine; the other 10 dogs were given a placebo. Overall improvement and change in total surface area of involvement and depth of the deepest fistula were determined after 4 weeks. Thereafter, cyclosporine-group dogs were treated for an additional 12 weeks and control-group dogs were treated with cyclosporine for 16 weeks.

RESULTS

All cyclosporine-group dogs, but none of the control-group dogs, were subjectively improved after 4 weeks. Mean total surface area and mean fistula depth decreased 78 and 62%, respectively, in the cyclosporine-group dogs but increased 29 and 11%, respectively, in the control-group dogs. After 16 weeks of cyclosporine treatment, fistulas had healed in 17 (85%) dogs. However, fistulas recurred in 7 of 17 dogs, and additional cyclosporine treatment or anal sacculectomy and surgical excision of fistulas was necessary.

CLINICAL IMPLICATIONS

Cyclosporine appeared to be effective in dogs with perianal fistulas. Even in dogs in which fistulas were not completely healed, cyclosporine administration appeared to be beneficial, because the surgical procedures that were required were less extensive than those that would have been necessary if cyclosporine had not been given.

Association of perianal fistula and colitis in the German shepherd dog: response to high-dose prednisone and dietary therapy

Twenty-seven German shepherd dogs with perianal fistulas and histological evidence of colitis were entered in a prospective clinical study to investigate the association between perianal fistula and colitis. Additionally, the response of perianal fistula disease to immunosuppressive doses of prednisone and an alternative protein diet was evaluated. All 27 cases completed the treatment protocol, and perianal fistulas completely resolved in nine (33.3%) cases, improved in nine cases, and remained unchanged in nine cases.

[Cysts of the hepatoid glands]

Cysts are specific rounded closed structures characteristic of some hepatoid glands. They never occur in other cutaneous glands of mammals. The cysts of the circumanal hepatoid glands of the dog and polar fox, the violet gland of the polar and common red fox, and the groin pouches of three species of gazelles were studied. The cyst is enclosed in a cellular wall saturated with glycogen. The amorphous content of the cyst is rich in hydrophobic lipids and it also contains protein. The cysts of the dog and gazelle contain also carboxylated mucopolysaccharides. The amorphous masses of the cyst are surrounded by concentric fibers rich in sulfated mucopolysaccharides. It was shown, using the circumanal glands of adult male dogs, that cysts are permanently formed from single secretory cells capable of synthesizing hydrophobic lipids before their destruction. During the involution of the hepatoid cysts (circumanal glands of an old female dog), whole acini and glandular lobes transform into cysts.

Anatomic predisposition to perianal fistulae formation in the German shepherd dog

Gross and microanatomic features which may predispose the German Shepherd Dog to perianal fistulae formation were studied in 2 groups of clinically healthy dogs: a predisposed group (German Shepherd Dogs) and a control group comprising breeds not ordinarily affected by perianal fistulae. The dimensions of the anal crypts (depth, base width, and length), measured and compared statistically between samples, identified no significant variation between groups (P greater than 0.05). Major tissue components of the anal canal were measured microscopically and were similarly evaluated: epithelial height in each zone, thickness of the lamina propria in each zone, thickness of the internal and external anal sphincter muscles, and density of the circumanal, sebaceous, and apocrine sweat glands. The only significant finding was an increase in density of apocrine sweat glands in the zona cutanea in the pre-disposed dog group. In a semiquantitative analysis of the inflammatory responses frequently seen in the anal glands, more mature fibroplasia was seen in the German Shepherd Dogs, indicating that inflammation was more longstanding in this group.

Carcinoma of the anal sac glands in ranch mink

During a 14-year period, carcinoma of the anal sac apocrine glands was found in 52 pastel and 8 sapphire mink (Mustela vison) kept for studies on slow viral diseases. The pastel mink varied in age from 72 to 135 months (mean age 108 months), the sapphire mink from 63 to 100 months (mean age 81 months). All but one pastel mink were females. The primary tumor varied in size from masses that caused bulges in the perineum to those that were found only after microscopic examination of the anal sac glands. Although the primary tumor grew mainly by expansion with little local infiltration, 41 of the 60 tumors had metastasized to the regional lymph nodes and sometimes also to more distant sites. The striking propensity of the carcinoma to metastasize while still small, even microscopic, often resulted in massive secondary growths, notably in the iliac lymph nodes. Hypercalcemia did not accompany the carcinoma. Its varied microscopic appearance included solid, glandular, squamous cell, and spindle or round cell components. Combinations of them formed mixed or complex histologic patterns, no doubt largely attributable to neoplastic proliferation of myoepithelial cells and squamous metaplasia of the apocrine gland epithelium. Although its cause remains obscure, the carcinoma appeared to arise from small foci of hyperplastic apocrine glands, sometimes in relation to both anal sacs. The tumor is a common and distinctive expression of neoplasia in older ranch mink.

Carcinoma of the perianal gland and associated structures in 1,2-dimethylhydrazine treated mice

Male C57BL/Icrf alpha t mice receiving long courses of weekly subcutaneous injections of 8.25 or 12.5 mg/kg, 1,2-dimethylhydrazine (DMH) developed perianal carcinomas as well as tumours at other sites. Tumours of the perianal gland or its associated hair root sheath and overlying skin included sebaceous gland adenocarcinomas, often with squamous metaplasia, analogous to those in the rat ear, and dysplasia, polyp formation and squamous cell carcinomas (SCC). Of 152 mice treated, 88 remained after 30 injections, and 10 out of a total of 14 tumours developed after 30 treatments. Perianal SCC without definite perianal gland association developed in 2 other animals.

Pathology of the anal glands with special reference to their mucin histochemistry

The anal gland pathology comprises cystic anal glands (so-called anal gland cyst hamartomas), anal gland carcinomas, and anal fistulas with or without carcinoma. The differential diagnosis of these conditions from other cysts and carcinomas of the anal region can be difficult. The authors have therefore compared conventional history with mucin histochemistry in normal and pathological anal glands. In contrast to normal rectal mucosa the mucus of anal glands was characterized by strong PAS-reactivity that was completely abolished after periodate borohydride saponification indicating scarcity of absence of O-acylated sialic acids in the anal gland mucus. A pattern similar to this was found in one of two tumours classified histologically as anal gland carcinomas, in four of eight colloid carcinomas arising in preexisting fistulas, and in two cases of mucoepidermoid carcinoma of the anal region. The results indicate that the method in some cases may be of value in differentiating between carcinomas arising in anal gland epithelium and in rectal mucosa. The cystic anal glands showed decreased secretion but no qualitative histochemical differences from anal glands. On the basis of the patients' histories it is suggested that the so-called anal gland cyst hamartoma at least in some cases could be an inclusion cyst of anal glands on the inflammatory basis.