Prognostic factors of visual field improvement after trans-sphenoidal approach for pituitary macroadenomas: review of the literature and analysis by quantitative method.

The objective of the study was to evaluate the preoperative visual field defect, the postoperative outcome and the possible prognostic factors in patients with pituitary macroadenoma, using a quantitative method (the mean deviation = MD), and to review the literature. A total of 73 patients, operated trough trans-sphenoidal approach, were selected, and data in single eyes were analysed by calculating the frequency and the degree of postoperative improvement (relative improvement). The visual field defect improved in 95.7% of eyes: The recovery was complete in 48.9% and partial in 46.8%. Multivariate logistic regression showed that factors, independently predictive for complete recovery, were as follows: low preoperative MD absolute value (p = 0.008), low cranio-caudal diameter of tumour (p = 0.02) and young age (p = 0.0001). The mean relative improvement in visual field defect (dMD%) was correlated with the preoperative visual acuity (p = 0.0001) and inversely related with the preoperative MD (p = 0.007) and the age (p = 0.017). The relative improvement was higher in tumours with a smaller cranio-caudal diameter (p = 0.0185). In conclusion, using a quantitative method, we can measure the degree of the postoperative visual field defect improvement. Predictive factors for a complete recovery were good preoperative visual function, young age and low cranio-caudal tumour.

The role of stereotactic radiotherapy in patients with growth hormone-secreting pituitary adenoma.

CONTEXT: Single-session stereotactic radiotherapy (SR) may be a potential adjuvant treatment in acromegaly. OBJECTIVE: We analyzed the safety and efficacy of SR in patients who had previously received maximal surgical debulking at our center. DESIGN: The study was a retrospective analysis of hormonal, radiological, and ophthalmologic data collected in a predefined protocol from 1994 through 2006. SETTING: The study was performed at a university hospital. PATIENTS: Eighty-three acromegalic patients, 52 women and 31 men, with a mean age of 42.6 +/- 1.2 yr, participated in the study. The median follow-up was 69 months (interquartile range 44-107 months). INTERVENTION: The patients were treated with SR for residual or recurrent GH-secreting adenoma. MAIN OUTCOME MEASURE: Normalization of age- and sex-adjusted IGF-I levels together with a basal GH level below 2.5 microg/liter without concomitant GH-suppressive drugs was the goal of therapy. RESULTS: Fifty patients (60.2%) reached the main outcome of the study. The rate of remission was 52.6% at 5 yr [95% confidence interval (CI) 40.6-64.6%]. Another 13 patients (15.7%), who were resistant to somatostatin analogs, were in remission after SR. Multivariate analysis showed that low basal GH and IGF-I levels were associated with a favorable outcome. No serious side effects occurred after SR. The 5-yr cumulative risk of new onset hypogonadism, hypothyroidism, or hypoadrenalism was 3.6% (95% CI 0-8.6%), 3.3% (95% CI 0-7.7%), and 4.9% (95% CI 0-10.4%), respectively. CONCLUSION: In a highly selected group of acromegalic patients, SR treatment had good efficacy and safety. This may lead to reconsider the role of SR in the therapeutic algorithm of acromegaly.

Early results of surgery in patients with nonfunctioning pituitary adenoma and analysis of the risk of tumor recurrence.

OBJECT: Nonfunctioning pituitary adenomas (NFPAs) are benign tumors of the pituitary gland that typically cause visual and/or hormonal dysfunction. Surgery is the treatment of choice, but patients remain at risk for tumor recurrence for several years afterwards. The authors evaluate the early results of surgery and the long-term risk of tumor recurrence in patients with NFPAs. METHODS: Between 1990 and 2005, 491 previously untreated patients with NFPA underwent surgery at the Università Vita-Salute. Determinations of recurrence or growth of the residual tumor tissue during the follow-up period were based on neuroradiological criteria. RESULTS: Residual tumor after surgery was detected in 173 patients (36.4%). Multivariate analysis showed that invasion of the cavernous sinus, maximum tumor diameter, and absence of tumor apoplexy were associated with an unfavorable surgical outcome. At least 2 sets of follow-up neuroimaging studies were obtained in 436 patients (median follow-up 53 months). Tumors recurred in 83 patients (19.0%). When tumor removal appeared complete, younger age at surgery was associated with a risk of tumor recurrence. In patients with incomplete tumor removal, adjunctive postoperative radiotherapy had a marked protective effect against growth of residual tumor. CONCLUSIONS: Complete surgical removal of NFPAs can be safely achieved in > 50% of cases. Visual symptoms and, less frequently, pituitary function may improve after surgery. However, tumor can recur in patients after apparently complete surgical removal. In patients with incomplete tumor removal, radiation therapy is the most effective adjuvant therapy for preventing residual tumor growth.

Stereotactic drainage and Gamma Knife radiosurgery of cystic brain metastasis.

OBJECT: Treatment options for patients with brain metastasis include tumor resection, whole-brain radiation therapy, and radiosurgery. A single treatment is not useful in cases of multiple tumors, of which at least 1 is a cystic tumor. The purpose of this study was to assess the role of stereotactic drainage and Gamma Knife surgery (GKS) in the treatment of cystic brain metastasis. METHODS: Between January 2001 and November 2005, 680 consecutive patients with brain metastases underwent GKS at our hospital, 30 of whom were included in this study (18 males and 12 females, mean age 60.6 +/- 11 years, range 38-75 years). Inclusion criteria were: 1) no prior whole-brain radiation therapy or resection procedure; 2) a maximum of 4 lesions on preoperative MR imaging; 3) at least 1 cystic lesion; 4) a Karnofsky Performance Scale score >or= 70; and 5) histological diagnosis of a malignant tumor. RESULTS: Non-small cell lung carcinoma was the primary cancer in most patients (19 patients [63.3%]). A single metastasis was present in 13 patients (43.3%). There was a total of 81 tumors, 33 of which were cystic. Ten patients (33.3%) were in recursive partitioning analysis Class I, and 20 (66.6%) were in Class II. Before drainage the mean tumor volume was 21.8 ml (range 3.8-68 ml); before GKS the mean tumor volume was 10.1 ml (range 1.2-32 ml). The mean prescription dose to the tumor margin was 19.5 Gy (range 12-25 Gy). Overall median patient survival was 15 months. The 1- and 2-year survival rates were 54.7% (95% confidence interval 45.3-64.1%) and 34.2% (95% confidence interval 23.1-45.3%). Local tumor control was achieved in 91.3% of the patients. CONCLUSIONS: The results of this study support the use of a multiple stereotactic approach in cases of multiple and cystic brain metastasis.

Presurgical treatment with somatostatin analogs in patients with acromegaly: effects on the remission and complication rates.

OBJECT: The question of whether preoperative therapy with somatostatin analogs can improve surgical outcome in acromegaly has not been definitively answered. In this paper, the authors report the effects of preoperative treatment with somatostatin analogs in a large sample of patients with acromegaly. METHODS: Between 1990 and 2003, 399 consecutive patients with acromegaly underwent surgery at the Istituto Scientifico San Raffaele. Thirty-three patients who had previously undergone surgery or radiation treatment, 48 patients treated with somatostatin analogs for fewer than 3 months, and patients who had stopped therapy for too long a time before surgery were excluded from the study. One hundred forty-three patients who had received somatostatin analogs prior to surgery (Group 1) were randomly matched to 143 patients who had never been treated with somatostatin analogs (Group 2). Matching criteria were tumor size and invasiveness into the cavernous sinus. Before surgery, Group 1 patients showed reduction of growth hormone levels to less than 50% of baseline in 64% of cases, but insulin-like growth factor-I was normalized in only 19.5%. Surgical remission occurred in 81 Group 1 patients (56.6%) and in 91 Group 2 patients (63.6%; p = 0.28). No significant difference in the remission rate was observed when cases were analyzed according to tumor size or invasiveness. Logistic regression analysis confirmed that pretreatment with somatostatin analogs was not associated with surgical outcome. Surgical morbidity was mild and similar in Group 1 and Group 2 patients (7 and 5.6%, respectively; p = 0.81). Surgical remission and complication rates in patients with acromegaly who received treatment with somatostatin analogs prior to surgery were not significantly different from those of matched patients who did not receive these agents. CONCLUSIONS: At present, the routine use of presurgical therapy with somatostatin analogs for patients with acromegaly cannot be recommended.

Radiosurgery and the prevention of regrowth of incompletely removed nonfunctioning pituitary adenomas.

OBJECT: The authors studied the efficacy of gamma knife radiosurgery (GKS) in the prevention of regrowth of nonfunctioning pituitary adenomas (NPA). METHODS: One hundred nineteen patients were included in this study and were divided into two groups. All patients had undergone surgery in our department and recurrent or residual adenoma was demonstrated on postoperative MR imaging. Group A consisted of 68 patients who were followed without additional treatment. Group B was composed of 51 patients who received GKS within 1 year after microsurgery. There was no significant demographic difference between the two groups. In Group B the mean margin dose was 16.5 +/- 0.3 Gy (range 13-21 Gy). Fifty one and one tenth percent of patients in Group A were recurrence free at 5 years and 89.8% in Group B (p < 0.001). In Group B patients, tumor volume decreased from a baseline value of 2.4 +/- 0.2 cm3 to 1.6 +/- 0.2 cm3 at last follow up (p < 0.001). CONCLUSIONS: The results of this study suggest that GKS is effective in controlling growth of residual NPA for at least 5 years following initial maximal surgical debulking compared with no radiation therapy. Thus, GKS is recommended after microsurgery when visible tumor can be detected on imaging studies.

Surgical treatment of prolactin-secreting pituitary adenomas: early results and long-term outcome.

Medical therapy with dopaminergic drugs is the preferred initial treatment for symptomatic prolactin (PRL)-secreting adenomas; but in recent years, there has been a renewed interest in surgery. The aim of this study is to report a large series of patients operated for prolactinoma in the last 10 yr. A total of 120 consecutive patients (93 female, 27 male) underwent surgery from January 1990 to December 1999. Their mean age at surgery was 29.7 +/- 0.9 yr. Fifty-nine patients (49.2%) had a microadenoma, and the remaining 61 (50.8%) had a macroadenoma, of which 24 (20%) were intrasellar and 37 (30.8%) were extrasellar adenoma. Magnetic resonance imaging signs of invasion of the cavernous sinus were detected in 18 patients (15.0%). Thirty-one patients (25.8%) had never been treated before, whereas the remaining 89 (74.2%) had received dopaminergic drugs. After surgery, normalization of PRL levels occurred in 77 patients (64.2%). Logistic regression analysis showed that the only predictive factor of unsuccessful surgery was a high preoperative PRL level. Recurrence of hyperprolactinemia occurred in 13 of the 77 cured patients (16.9%) during a mean follow-up of 50.2 +/- 3.0 months; the 5-yr disease-free survival was 75.9%. Extrasellar extension of the tumor and presence of a postoperative PRL response to TRH were associated with a lower risk of relapse. In summary, surgery normalized PRL levels and relieved symptoms of hyperprolactinemia in most patients. Recurrence of hyperprolactinemia occurred within 4 yr after surgery. Transsphenoidal surgery can be offered as a definitive therapy, especially to patients with intrasellar tumors.

Gamma knife surgery for treatment of residual nonfunctioning pituitary adenomas after surgical debulking.

OBJECT: Radiation therapy diminishes the risk of recurrence of incompletely removed nonfunctioning pituitary adenoma (NPA). The authors evaluated the efficacy and safety of gamma knife surgery (GKS) in patients with residual NPA following surgical debulking of the tumor. METHODS: Fifty-four patients, 26 men and 28 women, ranging in age from 29 to 72 years underwent gamma knife treatment. Baseline and follow-up studies involved magnetic resonance imaging, hormone evaluation, and neuroophthalmological examination 6 and 12 months after GKS and at yearly intervals thereafter. The mean follow up after GKS was 41.1 +/- 3.1 months. Two of 52 patients undergoing follow up had a recurrence 40 and 49 months after GKS. In both of these patients the treated lesion had reduced in size, but a new lesion appeared in the contralateral side of the sella turcica. The recurrence-free interval at 5 years was 88.2% (95% confidence interval 72.6-100%). Tumor volume decreased from a baseline value of 2.3 +/- 0.2 to 1.7 +/- 0.2 cm3 at the last follow up (p < 0.001). Twenty-two patients (42.3%) had a 20% or greater reduction in tumor volume. The administered radiation dose had been significantly higher in patients who experienced tumor reduction. Visual function and motility did not deteriorate in any patient. New cases of hypogonadism, hypothyroidism, and hypoadrenalism occurred in 12.5, 8.6, and 2.3%, respectively, of assessable patients at risk. CONCLUSIONS: Gamma knife surgery was effective in controlling the growth of residual NPA after previously performed maximal surgical debulking. The major advantage of GKS compared with fractionated radiotherapy seems to be a lower risk of side effects, especially a lower risk of hypopituitarism.

Neurosurgical treatment of craniopharyngioma in adults and children: early and long-term results in a large case series.

OBJECT: Craniopharyngioma accounts for 2%-5% of all primary intracranial neoplasms. The optimal management of craniopharyngioma remains controversial. The authors evaluated the early results of surgery and the longterm risk of tumor recurrence in a large series of patients undergoing resection of craniopharyngiomas. METHODS: Between 1990 and 2008, 112 consecutive patients (57 male and 55 female patients with a mean [± SEM] age of 33.3 ± 1.8 years) underwent resection of craniopharyngiomas at the authors' hospital. Recurrence or growth of residual tumor tissue during follow-up was assessed using MR imaging. RESULTS: There were 3 perioperative deaths (2.7%). Severe adverse events were more frequent in patients who underwent operations via the transcranial route (37%) than the transsphenoidal approach (5.6%; p < 0.001). Magnetic resonance imaging showed radical resection of the tumor in 78 (71.6%) of the remaining 109 patients. Previous surgery and maximum tumor diameter were associated with persistence of disease after surgery. Craniopharyngioma recurred in 26 (24.5%) of 106 patients. Presence of residual tumor on the first postoperative MR imaging, male sex, and no postoperative radiation therapy were associated with a risk of tumor recurrence. Quality-of-life data were assessed in the 91 patients who attended the authors' institution for follow-up visits. Among them, 8.8% patients were partially or completely dependent on others for daily living activities before surgery. This percentage increased to 14.3% at the last follow-up visit. The 5- and 10-year overall survival rates were 94.4% (95% CI 90.0%-98.8%) and 90.3% (95% CI 83.4%-97.3%), respectively. CONCLUSIONS: Complete surgical removal of craniopharyngioma can be achieved with reasonable safety in more than 70% of patients. Recurrence of craniopharyngioma may occur even after apparent radical excision. Prompt management of residual or recurring disease by radiotherapy, repeat surgery, or a combination of both is usually successful in controlling further tumor growth.

Persistent adrenocorticotropin response to desmopressin in the early postoperative period predicts recurrence of Cushing's disease.

CONTEXT: Patients with Cushing's disease (CD) often show an ACTH and cortisol response to desmopressin (DDAVP). OBJECTIVE: We tested whether persistence of a positive response to DDAVP after successful surgery identifies patients at risk of CD recurrence. DESIGN: We prospectively included all CD patients who had a positive response to DDAVP before successful surgery from 1995 through 2007. SETTING: The study was performed at a university hospital. PATIENTS: One hundred seventy-four patients with CD, 148 women and 26 men, mean age 36.1 +/- 0.8 yr, were studied. The median follow-up after surgery was 58 months (interquartile range 22-93 months). INTERVENTION: DDAVP test was performed immediately before and after surgery. MAIN OUTCOME MEASURE: An ACTH and cortisol increment of at least 30 and 20% above baseline, respectively, were considered as a positive response to DDAVP. The risk of CD recurrence was analyzed according to the postoperative hormonal response to DDAVP. RESULTS: Recurrence of CD occurred in 19 patients (10.9%). The recurrence-free survival at 5 yr was 89.8% [95% confidence interval (CI) 84.2-95.4]. Patients with a positive ACTH response had a 5-yr recurrence-free survival of 82.6% (95% CI 70.6-94.6%) as compared with 94.0% (95% CI 88.2-99.8%; P < 0.01) in patients without it. Multivariate analysis showed that persistence of a positive ACTH response to DDAVP was significantly associated with CD recurrence. CONCLUSION: Positive ACTH response to DDAVP after surgery is associated with an increased risk of CD recurrence. However, the specificity and predictive value of this finding are low.

Translaminar microsurgical approach for lumbar herniated nucleus pulposus (HNP) in the "hidden zone": clinical and radiologic results in a series of 24 patients.

STUDY DESIGN: Clinical series. OBJECTIVE: To describe an alternative surgical approach for disc herniations in the "hidden zone." SUMMARY OF BACKGROUND DATA: Many spine surgeons have suggested different surgical approaches for symptomatic preforaminal and foraminal disc herniations. However, almost every surgical approach has certain shortcomings when it comes to exposing the "hidden zone" without causing some degree of spinal instability. METHODS: Twenty-four patients with preforaminal and foraminal disc herniation underwent surgical treatment via a translaminar microsurgical approach. RESULTS.: Excellent results were obtained in all patients in terms of pain relief, and all had improvement in motor strength except for 1 patient. No spinal instability was seen at the latest follow-up. CONCLUSIONS: A classic interlaminar interspace approach combined with a very limited translaminar fenestration seem to be an acceptable surgical method for accessing a preforaminal disc herniation, and this technique has proven to be safe and did not cause any instability at the latest follow-up.

Surgical treatment of giant pituitary adenomas: strategies and results in a series of 95 consecutive patients.

OBJECTIVE: Giant pituitary adenomas, defined as those measuring at least 4 cm in maximum diameter, are a therapeutic challenge. We report our experience in a large, consecutive series of patients with giant adenomas. METHODS: Between 1990 and 2004, 95 patients with a giant pituitary adenomas underwent surgery at our department. Nonfunctioning pituitary adenoma was the most frequent type (n = 70; 73.7%), whereas hormone-secreting adenomas numbered only 25 (26.3%). The mean age at the time of surgery (+/-standard error of the mean) was 48.4 +/- 1.5 years; there were 66 men (69.5%) and 29 women (20.5%). RESULTS: In total, 111 surgical procedures were performed. Of these, 85 approaches (76.6%) were transsphenoidal and 26 (23.4%) were transcranial. Visual improvement occurred in 59 of the 79 patients with preoperative defect who could be evaluated after surgery (74.7%). Radical tumor excision was obtained in 14 patients (14.7%). Adjuvant medical and radiation therapies led to 74.5% (95% confidence interval, 62.7-86.4%) control of tumor growth at 5 years. This was not different in patients with nonfunctioning pituitary adenomas compared with patients with hormone-secreting tumors. In the subgroup of patients with nonfunctioning pituitary adenomas, radiation therapy had a protective role against tumor growth (P < 0.01). CONCLUSION: Maximal surgical removal of giant adenomas through the transsphenoidal or transcranial approach, or both, aimed to relieve compression of the optic pathway and reduce tumor volume as much as possible, offers the best chances to control the tumor when followed with adjuvant medical and radiation therapies.

Increased insulin-stimulated endothelin-1 release is a distinct vascular phenotype distinguishing Cushing's disease from metabolic syndrome.

OBJECTIVE: Although much is known about the anti-inflammatory effects of an acute corticosteroid therapy, little is known about the effects on chronic hypercortisolism on endothelial dysfunction and proinflammatory alterations in patients with Cushing's disease (CD). PATIENTS AND METHODS: We studied 9 patients with CD, 10 patients with metabolic syndrome and 27 normal controls. The tests consisted of an intravenous bolus of 0.1 U/kg insulin combined with a euglycaemic clamp technique with an arterialized forearm and assessment of the training parameters deep-venous balance of forearm glucose uptake (as an index of insulin sensitivity); NO(x) (nitric oxide end-products), c-GMP (second messenger of nitric oxide) and endothelin-1 release, as indices of endothelial function and proinflammatory systemic markers. RESULTS: Forearm glucose uptake incremental area was significantly lower in Cushing's disease and in the metabolic syndrome than in controls, suggesting a state of severe insulin resistance. Compared to controls and to the metabolic syndrome, basal and insulin-stimulated NO(x) release incremental areas were significantly reduced in Cushing's disease, while forearm c-GMP release was similarly decreased in CD and metabolic syndrome. By contrast, endothelin-1 incremental areas after insulin bolus were significantly higher in CD than in controls and the metabolic syndrome, in the presence of increased TNF-alpha, IL-6 and CRP levels. Forearm glucose uptake incremental area significantly correlated with NO(x) incremental area, forearm c-GMP release incremental area, TNF-alpha levels and ET-1 incremental area. CONCLUSIONS: In patients with CD, supraphysiological insulin levels are not able to overcome the insulin resistance due to chronic hypercortisolism. Furthermore, an increased proatherogenic risk profile is characterized by decreased nitric oxide synthesis and activity, enhanced endothelin-1 levels and increased proinflammatory markers.

Obstructive hydrocephalus and intracranial hypertension caused by a giant macroprolactinoma. Prompt response to medical treatment.

Patients with large prolactin (PRL)-secreting pituitary adenoma often have symptoms due to varying degree of hypopituitarism and/or mass effect on visual structures, while presentation with hydrocephalus is extremely uncommon. Even more exceptional is the development of the syndrome of intracranial hypertension as a consequence of tumor obstruction of the cerebrospinal fluid circulation. In this report, we describe a 26-year-old man who was referred to the emergency department of our hospital because of headache, nausea, and vomiting. Clinical and radiological assessment led to the diagnosis of obstructive hydrocephalus caused by a giant macroprolactinoma. The patient received a temporary external ventricular drainage to relieve the symptoms of intracranial hypertension. The same day, after we received the result of the basal PRL level, medical treatment with cabergoline was initiated. A prompt response to the drug ensued with resolution of the obstructive hydrocephalus, which allowed removal of the external ventricular drainage. Initial shrinkage of the mass was already noted on a magnetic resonance imaging performed 12 days thereafter. Subsequent medical treatment led to progressive and marked shrinkage of the tumor. Eighteen months after presentation the patient was well while on cabergoline treatment and showed no symptom attributable to compression of the surrounding nervous structures. Our report confirms that, even in cases of giant sellar mass with neurological symptoms, a rapid hormonal evaluation is mandatory. If a macroprolactinoma is diagnosed, treatment with dopamine agonists can lead to prompt clinical amelioration and shrinkage of the tumor, with eventual resolution of neurological symptoms.

Results of transsphenoidal surgery in a large series of patients with pituitary adenoma.

OBJECTIVE: To report the efficacy and safety of microsurgical transsphenoidal surgery in a series of previously untreated patients with pituitary adenoma. METHODS: One thousand one hundred forty consecutive patients undergoing transsphenoidal resection of a pituitary adenoma at our department from January 1990 through December 2002 were included in our study. Postoperative results were classified uniformly during the period of the study. Patients were considered in remission of disease when strict hormonal and radiological criteria of cure were met. RESULTS: The most frequent tumor type was clinically nonfunctioning adenoma (NFPA) (33.2%), followed by growth hormone-secreting adenoma (28.1%), adrenocorticotropin-secreting adenoma (23.0%), prolactin-secreting adenoma (13.2%), and last, thyrotropin-secreting adenoma (2.5%). The patient population was 59.7% female and 40.3% male. Mean age was 43.0 +/- 0.4 years. There were 788 macroadenomas (69.1%), and in 233 patients (20.4%), the tumor invaded one or both cavernous sinuses. The overall rate of early surgical success was achieved in 504 (66.1%) of the 762 patients with a hormone-active adenoma. Surgical outcome was better in patients with microadenomas than in patients with macroadenomas (78.9% and 55.5%, respectively), whereas tumors invading the cavernous sinus had a poorer outcome (7.4%). In patients with NFPA, no residual adenoma was present in 234 patients (64.8%). Normalization of visual defects occurred in 117 (40.5%) of the 289 patients with visual disturbances and improved in another 148 patients (51.2%). Three patients (0.3%) died as a consequence of surgery. CONCLUSION: Transsphenoidal surgery is an effective and safe treatment for most patients with pituitary adenoma and could be considered the first-choice therapy in all cases except for prolactinomas responsive to dopamine agonists. Other treatment methods, such as radiotherapy, stereotactic radiosurgery, and medical therapy, play an important role in patients not cured by surgery.

Spinal dural arteriovenous fistulae: analysis of outcome in relation to pretreatment indicators.

OBJECTIVE: The outcome of treatment for a spinal dural arteriovenous fistula is unpredictable. In this study, we reviewed the outcome of patients treated for this condition, in relation to pretreatment indicators. METHODS: We reviewed the records of 37 consecutive patients treated either surgically or endovascularly in our department between 1989 and 2002. RESULTS: At follow-up, 78% of the patients reported improvement. Those with motor symptoms had the best outcome: improvement was achieved in more than 60% of the patients, amounting to 1 or 2 points on the Aminoff scale. Sensory disorders improved in 43% of cases, pain in 61%, and sphincter impairment in only 37%. Patients with a fistula in the lower thoracic region did better than those with fistulae in other locations. CONCLUSION: The clinical state before treatment is certainly relevant in predicting outcome. Age and duration of the symptoms before treatment have no direct relation to the chances of improvement with treatment, particularly when motor improvement is considered. The modality of onset of symptoms and location of the fistula play significant roles, also: a fistula in the lower thoracic segment was associated with more severe symptoms but tended to improve more (83%, P = 0.04) after treatment. Midthoracic and lumbar fistulae showed a lower incidence of improvement (<50%).