Predictive factors for the development of visual loss in patients with pituitary macroadenomas and for visual recovery after optic pathway decompression

Objective: To investigate clinical and MRI findings that are predictive of both visual loss in patients with pituitary adenomas and visual recovery after treatment. Design: Cohort study. Participants: Thirty patients (60 eyes) with pituitary adenoma. Methods: Patients underwent neuro-ophthalmic examination and MRI before and after optic chiasm decompression. Visual field (VF) was assessed using the mean deviation in standard automated perimetry (SAP) and temporal mean defect, the average of 22 temporal values of the total deviation plot. Tumour size was measured on sagittal and coronal cuts. Results: Visual loss was found in 47 eyes; 35 had optic atrophy (subtle in 9, moderate in 14, and severe in 12). Before treatment, the average SAP mean deviation and temporal mean defect were -11.78 (SD 8.56) dB and -18.66 (SD 11.20) dB, respectively. The chiasm was 17.3 (SD 6.2, range 10-34) mm above the reference line on the sagittal and 21.8 (SD 8.3, range 12-39) mm on the coronal images. Tumour size correlated with the severity of VF defect. VF improvement occurred in 80% of eyes after treatment. The degree of optic atrophy, visual loss, and tumour size were significantly associated with improvement after treatment. Conclusions: The best predictive factor for visual loss was tumour size, and factors related to visual recovery were the degree of optic atrophy, the severity of VF defect, and the tumour size. Diagnosing pituitary adenomas before optic atrophy becomes severe may be related to a better prognosis in such patients.

Influence of Parasympathetic Modulation in Doppler Mitral Inflow Velocity in Individuals without Heart Disease

Background: The relation between left ventricular filing velocities determined by Doppler echocardiography and autonomic nervous system function assessed by heart rate variability (HRV) is unclear. The aim of this study was to evaluate the influence of the autonomic nervous system assessed by the time and frequency domain indices of HRV in the Doppler indices of left ventricular diastolic filling velocities in patients without heart disease. Methods: We studied 451 healthy individuals (255 female [56.4%]) with normal blood pressure, electrocardiogram, chest x-ray, and treadmill electrocardiographic exercise stress test results, with a mean age of 43 +/- 12 (range 15-82) years, who underwent transthoracic Doppler echocardiography and 24-hour electrocardiographic ambulatory monitoring. We studied indices of HRV on time (standard deviation [SD] of all normal sinus RR intervals during 24 hours, SD of averaged normal sinus RR intervals for all 5-minute segments, mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals > 50 ms) and frequency (low frequency, high frequency, very low frequency, low frequency/high frequency ratio) domains relative to peak flow velocity during rapid passive filling phase (E), atrial contraction (A), E/A ratio, E-wave deceleration time, and isovolumic relaxation time. Statistical analysis was performed with Pearson correlation and logistic regression. Results: Peak flow velocity during rapid passive filling phase (E) and atrial contraction (A), E/A ratio, and deceleration time of early mitral inflow did not demonstrate a significant correlation with indices of HRV in time and frequency domain. We found that the E/A ratio was < 1 in 45 individuals (10%). Individuals with an E/A ratio < 1 had lower indices of HRV in frequency domain (except low frequency/high frequency) and lower indices of the mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals > 50 ms in time domain. Logistic regression demonstrated that an E/A ratio < 1 was associated with lower HF. Conclusion: Individuals with no evidence of heart disease and an E/A ratio < 1 demonstrated a significant decrease in indexes of HRV associated with parasympathetic modulation. (J Am Soc Echocardiogr 2010;23: 762-5.)

Relationship between Optical Coherence Tomography, Pattern Electroretinogram and Automated Perimetry in Eyes with Temporal Hemianopia from Chiasmal Compression

PURPOSE. To evaluate the relationship between pattern electroretinogram (PERG) amplitude, macular and retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), and visual field (VF) loss on standard automated perimetry (SAP) in eyes with temporal hemianopia from chiasmal compression. METHODS. Forty-one eyes from 41 patients with permanent temporal VF defects from chiasmal compression and 41 healthy subjects underwent transient full-field and hemifield (temporal or nasal) stimulation PERG, SAP and time domain-OCT macular and RNFL thickness measurements. Comparisons were made using Student`s t-test. Deviation from normal VF sensitivity for the central 18 of VF was expressed in 1/Lambert units. Correlations between measurements were verified by linear regression analysis. RESULTS. PERG and OCT measurements were significantly lower in eyes with temporal hemianopia than in normal eyes. A significant correlation was found between VF sensitivity loss and fullfield or nasal, but not temporal, hemifield PERG amplitude. Likewise a significant correlation was found between VF sensitivity loss and most OCT parameters. No significant correlation was observed between OCT and PERG parameters, except for nasal hemifield amplitude. A significant correlation was observed between several macular and RNFL thickness parameters. CONCLUSIONS. In patients with chiasmal compression, PERG amplitude and OCT thickness measurements were significant related to VF loss, but not to each other. OCT and PERG quantify neuronal loss differently, but both technologies are useful in understanding structure-function relationship in patients with chiasmal compression. (ClinicalTrials.gov number, NCT00553761.) (Invest Ophthalmol Vis Sci. 2009; 50: 3535-3541) DOI:10.1167/iovs.08-3093

Agreement between stress intraocular pressure and long-term intraocular pressure measurements in primary open angle glaucoma

The aim of this paper is to study the correlation between the intraocular pressure peaks and fluctuation detected during the water drinking test and the same parameters observed during long-term follow up. This prospective cohort study enrolled 22 eyes of 22 newly diagnosed primary open angle glaucoma patients. After an initial complete ophthalmological examination, patients were started on antiglaucoma medication and returned 4 weeks later to perform the water drinking test. Thereafter, patients were evaluated at least eight times within a period of 6-12 months. The intraocular pressure peaks and fluctuation detected during the water drinking stress test were compared with those observed during regular office visits. Spearman`s correlation coefficient and Bland-Altman Plots were used for statistical analysis. The mean age of participants was 54.3 +/- 8.2 years (+/- SD), 59% were women, and average mean deviation -10.2 +/- 4.5 dB. The mean follow-up period was 8.2 +/- 2.0 months. The average intraocular pressure peaks and fluctuation during the water drinking test were 20.0 +/- 2.9 mmHg and 40 +/- 10%, respectively, and 18.1 +/- 2.8 mmHg and 30 +/- 10% during follow up. Spearman`s correlation coefficients were significant and strong between the intraocular pressure peaks and fluctuation detected during the water drinking test and during the follow-up period (P < 0.001, rho = 0.76 and 0.82, respectively). There was good agreement between the variables. The intraocular pressure peaks and fluctuation detected during the water drinking test showed significant correlation and agreement with the pressures observed during follow-up visits. Stress tests could be used to estimate long-term intraocular pressure variation.

Efficacy and Tolerability of Lodenafil Carbonate for Oral Therapy in Erectile Dysfunction: A Phase II Clinical Trial

Oral treatment with phosphodiesterase type 5 inhibitor (PDE5) is considered the first-line treatment for patients with erectile dysfunction (ED). Lodenafil carbonate (LC) is a novel PDE5. This is a phase II, prospective, randomized, double-blind, and placebo controlled clinical trial of LC. Efficacy end points were International Index of Sexual Function (IIEF) erectile domain, IIEF questions 3 and 4, and Sexual Encounter Profile (SEP) questions 2 and 3, before and after the use of LC or placebo. Seventy-two men older than 18 years, with ED for at least 6 months with stable sexual relationship were enrolled. Patients were randomized to placebo or LC 80 mg, 40 mg, or 20 mg and followed for 4 weeks. IIEF erectile domain scores before and after the use of medications were (mean +/- standard deviation [SD]): placebo: 11.9 +/- 3.4 and 12.6 +/- 5.5; LC 20 mg: 15.8 +/- 4.1 and 18.9 +/- 6.6; LC 40 mg: 11.9 +/- 4.4 and 15.4 +/- 8.1; LC 80 mg: 14.2 +/- 4.7 and 22.8 +/- 6.0 (anova P < 0.01). The SEP-2 scores before and after the use of medications were (Mean +/- SD): placebo: 71.0 +/- 33.1 and 51.2 +/- 43.1; LC 20 mg 70.3 +/- 34.2 and 75.5 +/- 31.5; LC 40 mg: 48.4 +/- 42.1 and 60.8 +/- 42.5; LC 80 mg: 68.6 +/- 33.5 and 89.6 +/- 26.0. The SEP-3 scores were: placebo 23.3 +/- 27.6 and 33.6 +/- 42.3; LC 20 mg: 32.3 +/- 38.9 and 51.2 +/- 41.7; LC 40 mg: 39.7 +/- 44.7 and 46.7 +/- 41.1; LC 80 mg* 17.2 +/- 29.5 and 74.3 +/- 36.4 (*P < 0.05 for difference to placebo). The drug was well tolerated. Adverse reactions were mild and self-limited and included headache, rhinitis, flushing, color visual disorders, and dyspepsia. This study showed that the dosage of 80 mg of LC was significantly more efficacious than placebo and well tolerated. Glina S, Toscano I, Gomatzky C, de Goes PM, Junior AN, de Almeida Claro JF, and Pagani E. Efficacy and tolerability of lodenafil carbonate for oral therapy in erectile dysfunction: A phase II clinical trial. J Sex Med 2009;6:553-557.

SPINAL POSTURAL ALIGNMENT VARIANCE ACCORDING TO SEX AND AGE IN 7-AND 8-YEAR-OLD CHILDREN

Purpose: Children`s postural alignment undergoes many adjustments due to the changes in body proportions during the stages of growth. The objective of this study was to quantitatively characterize and analyze spinal postural standards in 7- and 8-year-old children to verify which of the differences found were correlated to age and sex. Methods: Two hundred thirty public school students (Amparo, Sao Paulo, Brazil) aged 7 to 8 years were divided into groups according to postural alignment, which were further subdivided by sex and age, for comparison. Digital photos of upright Subjects were analyzed to evaluate posture. Lumbar and thoracic curvature, pelvic inclination, head posture, and lateral spine deviation were measured using CorelDraw (Ottawa, Canada) software guidelines and bone landmarks. Descriptive statistics and analysis of variance data analysis were utilized to verify differences among the groups. This was a cross-sectional, descriptive study. Results: Mean values for the variables analyzed were calculated. For lumbar lordosis, 7-year-old boys showed 38.49 degrees +/- 15.32 degrees in comparison to all other groups (42.29 degrees +/- 7.13 degrees). For thoracic kyphosis, the 7-year-old children presented 28.07 degrees +/- 7.73 degrees. and the 8-year-olds 30.32 degrees +/- 7.73 degrees. Pelvic inclination presented a mean value of 15.82 degrees +/- 5.46 degrees and single lateral spine deviation mean value of 3.48 degrees +/- 2.12 degrees. Conclusion: For the sample studied, differences based on sex and age were found for some of the body segments analyzed. The values found in this study may contribute to improved physiotherapeutic treatment when associated with other aspects of the clinical assessment and symptomatology. (J Manipulative Physiol Ther 2009;32: 154-159)

Automatic versus manual pressure support reduction in the weaning of post-operative patients: a randomised controlled trial

Introduction Reduction of automatic pressure support based on a target respiratory frequency or mandatory rate ventilation (MRV) is available in the Taema-Horus ventilator for the weaning process in the intensive care unit (ICU) setting. We hypothesised that MRV is as effective as manual weaning in post-operative ICU patients. Methods There were 106 patients selected in the postoperative period in a prospective, randomised, controlled protocol. When the patients arrived at the ICU after surgery, they were randomly assigned to either: traditional weaning, consisting of the manual reduction of pressure support every 30 minutes, keeping the respiratory rate/tidal volume (RR/TV) below 80 L until 5 to 7 cmH(2)O of pressure support ventilation (PSV); or automatic weaning, referring to MRV set with a respiratory frequency target of 15 breaths per minute (the ventilator automatically decreased the PSV level by 1 cmH(2)O every four respiratory cycles, if the patient`s RR was less than 15 per minute). The primary endpoint of the study was the duration of the weaning process. Secondary endpoints were levels of pressure support, RR, TV (mL), RR/TV, positive end expiratory pressure levels, FiO(2) and SpO(2) required during the weaning process, the need for reintubation and the need for non-invasive ventilation in the 48 hours after extubation. Results In the intention to treat analysis there were no statistically significant differences between the 53 patients selected for each group regarding gender (p = 0.541), age (p = 0.585) and type of surgery (p = 0.172). Nineteen patients presented complications during the trial (4 in the PSV manual group and 15 in the MRV automatic group, p < 0.05). Nine patients in the automatic group did not adapt to the MRV mode. The mean +/- sd (standard deviation) duration of the weaning process was 221 +/- 192 for the manual group, and 271 +/- 369 minutes for the automatic group (p = 0.375). PSV levels were significantly higher in MRV compared with that of the PSV manual reduction (p < 0.05). Reintubation was not required in either group. Non-invasive ventilation was necessary for two patients, in the manual group after cardiac surgery (p = 0.51). Conclusions The duration of the automatic reduction of pressure support was similar to the manual one in the postoperative period in the ICU, but presented more complications, especially no adaptation to the MRV algorithm. Trial Registration Trial registration number: ISRCTN37456640

Radical Retropubic Prostatectomy for Localized Prostate Cancer in Renal Transplant Patients

OBJECTIVE To investigate the feasibility of radical retropubic prostatectomy (RRP) in renal transplant recipients with clinically localized prostate cancer. METHODS A prospective protocol was established between August 2004 and November 2007. In that period, 8 patients diagnosed with localized prostate cancer were submitted to RRP, and their clinicopathologic data were reviewed. RESULTS The mean age (standard deviation) at surgery was 59.6 +/- 6.7 years (range, 49-67 years). All patients had TIC tumors, except for 1 with a T2A tumor. The mean preoperative prostate-specific antigen value was 4.5 +/- 1.8 ng/mL (range, 1.6-7.0 ng/mL). The mean interval between renal transplantation and RRP was 89.9 +/- 65.1 months (range, 40-209 months). The procedure was well tolerated without major complications, and all patients were discharged on the fifth postoperative day. There was no impairment to bladder descent caused by the presence of the allograft or the ureteroneocystostomy. Urethrovesical anastomosis was easily performed in all cases in the standard manner. Blood transfusion was needed in 2 patients (1 received 2 U and another 5 U of blood). The mean operative duration was 183 +/- 29.7minutes (range, 150-240 minutes), the mean estimated blood loss was 656 +/- 576 mL (range, 100-2000 mL), and no deterioration of graft function was observed. All patients were followed, and the mean follow-up was 10.5 months (range, 2-30 months). Prostate-specific antigen was undetectable in all cases during this time frame. CONCLUSIONS Radical retropubic prostatectomy in renal transplant patients is safe, effective, and can be easily performed in the same manner as described by Walsh, regardless of the presence of the allograft. The only necessary technical modification is the avoidance of ipsilateral lymphadenectomy to prevent damage to the transplanted organ. UROLOGY 72: 1362-1365, 2008. (C) 2008 Elsevier Inc.

Clinical Treatment of Ocular Demodex folliculorum by Systemic Ivermectin

PURPOSE: To report clinical outcomes of the treatment of ocular Demodex folliculorum with oral ivermectin. DESIGN: Noncomparative, interventional case series. METHODS: Setting. Institutional. Study Population. Twenty-four eyes of 12 patients (3 male and 9 female; mean age +/- standard deviation, 50.4 +/- 21.0 years) with refractory posterior blepharitis with the presence of D. folliculorum in lash samples were enrolled in this study. Intervention. Patients were instructed to take 1 dose of oral ivermectin (200 mu g/kg). All patients were instructed to repeat the treatment after 7 days. Main outcome measures. Tear meniscus height, Schirmer I test results, noninvasive tear film break-up time (BUT), quantification of the absolute number of D. folliculorum found in the lashes, and corneal fluorescein and rose bengal staining scores were obtained from all patients 1 day before and 28 days after treatment. RESULTS: Statistical improvement was observed in the absolute number of D. folliculorum found in the lashes after the treatment with oral ivermectin. Average values of Schirmer I test results and tear film break-up time improved statistically after the treatment of oral ivermectin. No statistical improvement was observed in average lacrimal meniscus height or value of corneal fluorescein and rose bengal staining after treatment with oral ivermectin. CONCLUSIONS: Ivermectin successfully reduced the number of D. folliculorum found in the lashes of patients with refractory blepharitis. Oral ivermectin may be very useful as a complement in the treatment of D. folliculorum infestation with ocular manifestation, especially in cases of unsuccessful treatment related to patient compliance. (Am J Ophthalmol 2011;151:1030-1034. (C) 2011 by Elsevier Inc. All rights reserved.)

High prevalence of pituitary magnetic resonance abnormalities and gene mutations in a cohort of Brazilian children with growth hormone deficiency and response to treatment

Data were retrospectively collected from 69 Brazilian patients (45 boys) with growth hormone deficiency (GHD) who received exogenous growth hormone (GH) for a median duration of 4 years (range 1-13 years). Forty-two patients had multiple pituitary hormone deficiencies and 27 had isolated GHD. Peak GH was <7 ng/ml (IRMA) or <3.2 ng/ml (IFMA) after two stimulation tests.. Therapy was started at median age of 10.0 years (range 2.2-21.6 years), bone age of 5.8 years (0.5-13.5 years) and height standard deviation score -4.4 (range -9.3 to -1.6). MRI revealed pituitary abnormalities in 87% of patients. Homozygous mutations in PROP-1, GHRH-R, GH-1 or HESX-1 genes were found in 12 patients. Mean height velocities were 3.3 pretreatment and 10.3, 7.8, 7.4 and 6.4 cm/yr, respectively, during 1-4 years of treatment with GH. In conclusion, the high prevalence (96%) of genetic and/or pituitary abnormalities probably reflects the stringent diagnostic criteria used, and GH replacement resulted in significant catch-up growth.

Enantioselective Determination of Mexiletine and Its Metabolites p-Hydroxymexiletine and Hydroxymethylmexiletine in Rat Plasma by Normal-Phase Liquid Chromatography-Tandem Mass Spectrometry: Application to Pharmacokinetics

Mexiletine (MEX), hydroxymethylmexiletine (HMM) and P-hydroxy-mexiletine (PHM) were analyzed in rat plasma by LC-MS/MS. The plasma samples were prepared by liquid-liquid extraction using methyl-tert-butyl ether as extracting solvent. MEX, HMM, and PHM enantiomers were resolved on a Chiralpak (R) AD column. Validation of the method showed a relative standard deviation (precision) and relative errors (accuracy) of less than 15% for all analytes studied. Quantification limits were 0.5 ng ml(-1) for the MEX and 0.2 ng ml(-1) for the HMM and PHM enantiomers. The validated method was successfully applied to quantify the enantiomers of MEX and its metabolites in plasma samples of rats (n = 6) treated with a single oral dose of racemic MEX. Chirality 21:648-656, 2009. (C) 2008 Wiley-Liss, Inc.

3.0-T MRI evaluation of patients with chronic liver diseases: initial observations

Purpose: To describe the use of 3.0-T magnetic resonance imaging (MRI) for the evaluation of chronic liver diseases. Materials and Methods: Two groups of patients who had chronic liver diseases and underwent 3.0-T MRI for evaluation of the liver were included in the study. The first group of patients included 66 consecutive patients (33 male, 33 female; mean age +/- standard deviation, 56 +/- 11). The second group of patients included 30 consecutive patients (18 males, 12 females; mean age +/- standard deviation, 53 +/- 10) in whom Variable-Rate Selective Excitation (VERSE) pulses and improved adjustments procedure were used during the acquisitions. Imaging findings of chronic liver diseases, predetermined artifacts and image quality of all individual sequences in the first group and predetermined artifacts and image quality of T2-weighted sequences in the second group were reviewed retrospectively and independently by two reviewers. chi-Square tests were used to compare the findings between two groups of patients and individual sequences. Kappa statistics were used to determine the extent of agreement between the reviewers. Results: Fifteen dysplastic nodules in 6 of 66 (9%) patients and 12 hepatocellular carcinomas in 11 of 66 (17%) patients were detected. Excluding motion artifacts, three-dimensional (313) T1-weighted gradient-echo (GE) sequence was the least affected sequence by the artifacts. Image quality of T1-weighted 3D-GE sequences was excellent in 43 of 66 (65%) patients. In-phase and out-of-phase T1-weighted spoiled GE (SGE) images were fair in 62 of 66 (94%) and 61 of 66 (92%) patients, respectively. The image quality of short tau inversion recovery (STIR) and half-Fourier rapid acquisition with relaxation enhancement (RARE) sequences were fair in 31 of 66 (47%) and 53 of 66 (80%) patients. STIR and half-Fourier RARE sequences in the second group demonstrated significantly better image quality (P=.03 and P<.0001). Conclusion: 3.0-T MRI allows the acquisition of very high quality postgadolinium 3D-GE sequence, which permitted the detection and characterization of lesions in the setting of chronic liver diseases. The use of VERSE pulses and improved adjustments procedure improved the image quality of T2-weighted sequences. In-phase/out-of-phase SGE sequences are at present of fair quality. (C) 2008 Elsevier Inc. All rights reserved.

Water excitation MPRAGE: An alternative sequence for postcontrast imaging of the abdomen in noncooperative patients at 1.5 Tesla and 3.0 Tesla MRI

Purpose: To evaluate the diagnostic image quality of post-gadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI. Materials and Methods: Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T. 10 under-went noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers. Results: The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T. in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042: respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement. Conclusion: WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.

Influence of Nocturnal Asthma on Chronotype

Individual differences in circadian rhythm have been studied since the past century. Chronotypes are a chronobiology classification based on the preferential times for beginning and ending activities throughout the day. Chronotypes can be classified as definitely morning, moderately morning, indifferent, moderately evening, and definitely evening. We aim to assess the distribution of chronotypes in asthmatics and the relationship of chronotype to the presence of nocturnal symptoms. Two hundred subjects were evaluated, 100 asthmatics and 100 non-asthmatics. The Morningness/Eveningness questionnaire was applied for chronotype determination. The asthmatics were subdivided according to the presence or absence of nocturnal symptoms. The chronotype distribution did not differ significantly between asthmatics and non-asthmatics. Thirty-five percent of the asthma group reported nocturnal symptoms. There was a significant difference in chronotype distribution between asthmatics with and without nocturnal worsening. The asthmatics with nocturnal symptoms had a lower prevalence of morning types and had a greater predominance of indifferent chronotype compared to asthmatics without nocturnal symptoms (p = 0.011). In conclusion, asthmatics with nocturnal symptoms present deviation from the chronotype distribution curve when compared to asthmatics without nocturnal symptoms. This is the first study to show the effect of a disease on chronotypes.

Experimental model for study of anorectal sphincter musculature by manometry and computerized tomography in piglets

There seems to be controversy on the anorectal sphincter presentation and anatomical division, as well as on its functional representation. Evaluation of the anorectal sphincter musculature has been achieved through several methods, including anorectal manometry and computerized tomography, but to date there is no experimental model allowing a detailed manometric study of this muscle complex. In this work, we have developed such a model, which should enable the manometric and radiographic study of the anatomical features and functional mechanisms of sphincteric injuries, as well as the assessment of drug effects on the anorectal musculature upon incontinence and constipation. Twenty-two piglets (aged 25-30 days, weighing 5-7 kg) were studied by anorectal manometry (rectoanal inhibitory reflex and vector volume) and computerized tomography (anorectal angle and anal canal length). The data obtained for the rectoanal inhibitory reflex, represented here as the average and standard deviation, were the following: relaxation duration = 14.75 +/- 3.62 s, sphincter basal pressure = 41.58 +/- 8.20 mmHg, relaxation index = 87.26 +/- 11.52%, speed of relaxation = 5.90 +/- 2.10 mm/s, and speed of relaxation recovery = 4.03 +/- 1.78 mm/s. As for the vector volume, results were as follows: vector volume = 2692.32 +/- 1298.12 mmHg(2) cm, sphincter length = 11.82 +/- 2.74 mm, high pressure zone length = 5.09 +/- 1.34 mm, maximum pressure = 61.50 +/- 20.58 mmHg, and asymmetry index = 43.50 +/- 10.03%. Radiographic evaluation led to the following results: anal canal length = 9.61 +/- 2.14 mm and anorectal angle = 137.91 +/- 7.75 degrees. The experimental model designed here allows both anorectal manometry and computerized tomography to be carried out in the same way it is performed in human beings, as long as animal sedation is strictly controlled.