Colovesical fistula: review on conservative management, surgical techniques and minimally invasive approaches.

Colovesical fistula (CVF) is an abnormal communication between bowel and urinary bladder. Main causes are represented by complicated diverticular disease, colonic and bladder cancer and iatrogenic complications. Diagnosis is often based on patognomonic signs: faecaluria, pneumaturia and recurrent urinary tract infections. Treatment of CVF includes non-surgical and surgical strategy. The non-surgical treatment is reserved to selected patients who are unfit for surgery. Surgery of CVFs is determined by the site of the colonic lesion and patient's comorbidity. However the surgical one-stage approach should be preferred, reserving the multi-stage procedure in patients with a pelvic abscess, or with advanced malignancy, or previous radiation therapy. The sole defunctioning stoma may be an option to improve the quality of life in patients unfit for bowel resection. In open surgery the standard operative management consists in resection and anastomosis of the involved bowel segment and closure of the bladder. Laparoscopic treatment of CVFs is feasible and safe if performed by skilled surgeons. Robotic surgery for CVF treatment is safe and feasible similarly to laparoscopic one and it seems to reduce the conversion rate with respect to laparoscopy. However, further studies are needed to evaluate the advantages of robotic surgery over laparoscopy in the management of CVF. Currently, in Literature it is still debated which is the best surgical approach for CFV treatment due to the lack of RCTs and CCTs, the small sample size and the short follow-up. Further studies with higher quality and larger sample size are necessary to state the gold standard surgical treatment of CVFs.

Endogenous beta-endorphins in hypertension: correlation with 24-hour ambulatory blood pressure.

OBJECTIVES: The aims of this study were to determine whether hypertensive patients showed increased endogenous opioid tone and to find a possible correlation between beta-endorphin levels and 24-h ambulatory blood pressure. We also investigated whether circulating beta-endorphin levels were associated with pain perception at rest. BACKGROUND: Experimental studies suggest an involvement of the endogenous opioid system in cardiovascular control mechanisms. METHODS: We determined baseline beta-endorphin plasma levels by radioimmunoassay in 81 consecutive subjects (48 hypertensive, 33 normotensive) after a 30-min rest and before 24-h ambulatory blood pressure monitoring. In 72 of 81 subjects with a dental formula suitable for the pulpar test (graded increase of test current -0 to 0.03 mA applied to three healthy teeth), pain perception was also investigated. RESULTS: Hypertensive patients showed higher beta-endorphin plasma levels than normotensive subjects (p < 0.002). Circulating endogenous opioid levels correlated with 24-h diastolic blood pressure (p < 0.01), whereas the relation with systolic pressure did not reach statistical significance. When 24-h blood pressure recordings were divided into daytime and nighttime values, and blood pressure loads (percent of measurements > or = 140 mm Hg for systolic blood pressure and > or = 90 mm Hg for diastolic pressure) were calculated, a significant correlation was found between beta-endorphin levels and diastolic pressures and load. Similarly, presampling diastolic blood pressure was significantly correlated with beta-endorphin levels. Of the 72 subjects tested, hypertensive patients showed a lower pain sensitivity than normotensive subjects. A positive correlation was found between pain threshold and circulating beta-endorphin levels (p < 0.05). CONCLUSIONS: Sustained arterial pressure is probably involved in the tonic activation of cardiovascular mechanisms linked to endogenous opioid tone. Circulating plasma endorphins may account, at least in part, for the pain perception pattern relating to blood pressure levels at rest.

Twenty-four-hour noninvasive blood pressure monitoring and pain perception.

Although a hypertension-related hypalgesia has been described, the relation between pain perception and the 24-hour blood pressure trend is still unknown. The ambulatory blood pressure monitoring parameters and dental pain sensitivity were correlated in 67 male subjects. The pulpar test (graded increase of test current of 0 to 0.03 mA) was performed on three healthy teeth, and mean dental pain threshold (occurrence of pulp sensation) and pain tolerance (time when the subjects asked for the test to be stopped) were evaluated. Three groups of subjects with normal (n = 34), intermediate (n = 13), and high (n = 20) blood pressure values were identified according to ambulatory monitoring results. Pain threshold differed among the three groups (P < .02), being higher in the group with highest blood pressure. The groups of hypertensive subjects showed higher pain tolerance than the normotensive group (P < .02). Pain threshold was correlated with 24-hour, diurnal, and nocturnal blood pressure values. Pain tolerance was also related to 24-hour blood pressure and to diurnal and nocturnal diastolic and mean arterial pressure values. Systolic and diastolic blood pressure loads were significantly associated with pain threshold, and diastolic load was also associated with tolerance. The blood pressure variability (SD) did not relate to pain perception. The 24-hour arterial pressure was more closely associated with pain perception than the blood pressure values obtained before the pulpar test. A close correlation between pain perception and 24-hour ambulatory blood pressure was demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment with enalapril modifies the pain perception pattern in hypertensive patients.

The cardiovascular system shares numerous anatomic and functional pathways with the antinociceptive network. The aim of this study was to investigate whether angiotensin-converting enzyme (ACE) inhibitor treatment could affect hypertension-related hypalgesia. Twenty-five untreated hypertensive patients, together with a control group of 14 normotensive subjects, underwent dental pain perception evaluation by means of a pulpar test (graded increase of test current applied to healthy teeth). After the evaluation of the dental pain threshold (occurrence of pulp sensation) and tolerance (time when the subjects asked for the test to be stopped), all the subjects underwent a 24-hour ambulatory blood pressure monitoring. The hypertensive group then was treated with 20 mg/d enalapril, whereas the normotensive subjects remained without any treatment. After a time interval of 6+/-2 months, the dental pain sensitivity was retested in all the subjects, and ambulatory blood pressure was recorded during treatment in the hypertensive patients. At the first assessment, hypertensive patients showed a higher pain threshold than normotensive subjects (P<.001). On retesting of pain sensitivity in hypertensive patients, a significant decrease of both pain threshold and tolerance, leading to their normalization, was observed during treatment (P<.001 and P<.005, respectively), in the presence of reduced 24-hour and office blood pressure values. A slight, though significant, correlation was observed between variations in pain tolerance and baseline blood pressure changes occurring during treatment. During follow-up, the normotensive subjects did not show any significant pain perception or office blood pressure changes. Hypertension-related hypalgesia was confirmed. Mechanisms acting both through lowering of blood pressure and specific pharmacodynamic properties may account for the normalization of pain sensitivity observed in hypertensive patients during treatment with ACE inhibitors.

Effects of arithmetic mental stress test on hypertension-related hypalgesia.

AIM: Though hypertension-related hypalgesia has been described, little is known about possible variation of pain perception after mental stress. The aims of the present study were to determine (1) whether mental stress can influence pain perception in normotensive and hypertensive subjects and (2) whether blood pressure levels before pain evaluation can account for changes in pain sensitivity. PATIENTS AND METHODS: A pulpar test (graded increase in test current of 0-0.03 mA applied on healthy teeth) was performed twice (time interval 15 min) in 62 subjects. Thirty-eight subjects (group 1) performed an arithmetic mental stress test immediately after the first pulpar test while 24 subjects (group 2) did not. The pain threshold (occurrence of pulp sensation) was evaluated as the mean value of three teeth tested on each subject and as the value on the most sensitive tooth. RESULTS: Twenty-eight subjects with normal 24-h blood pressure showed a lower mean pain threshold than 34 subjects with high 24-h blood pressure values (P<0.02). In group 1 (20 normotensives, 18 hypertensives), even when the mental stress increased the pretest blood pressure, the pressure values immediately before both pulpar tests remained similar. In the second pulpar test, a significant increase in the pain threshold on the most sensitive tooth was observed in group 1 (P<0.005). Though a trend towards an increase in the pain threshold was found in both the subgroups of normotensive and hypertensive subjects, the difference was significant in hypertensives only. However, group 2 subjects showed unchanged pain sensitivity on the second test. CONCLUSIONS: A mental stress-induced reduction in pain sensitivity was observed in the absence of change in arterial pressure measured immediately before pulpar tests. A blood pressure increase during the test and, more likely, cortical and humoral activation during stress, may account for the variation found in pain perception.

Relationship between dental pain perception and 24 hour ambulatory blood pressure: a study on 181 subjects.

OBJECTIVE: To investigate dental pain perception in a large group of essential hypertensive subjects. METHODS: A total of 130 hypertensive patients together with 51 normotensive subjects were submitted to tooth-electrical stimulation to determine the dental pain threshold (occurrence of pulp sensation) and tolerance (time when the subject asked for the test to be stopped). Blood pressure was measured at rest, before pain perception evaluation, and during a 24 h period by ambulatory monitoring. RESULTS: The normotensive and hypertensive subjects differed with regard to pain threshold (P = 0.002) and tolerance (P = 0.01). Pain perception variables were significantly correlated with both resting blood pressure and 24 h, diurnal and nocturnal arterial pressures, the correlation between pain threshold and 24 h systolic blood pressure being the most significant (r = 0.31, P < 0.0001). By contrast, parameters indicating 24 h blood pressure variability (percentage of nocturnal blood pressure reduction and 24 h blood pressure variation coefficients) were not associated with pain perception. Moreover, among the hypertensives only, a significant relationship was observed between pain sensitivity and both baseline and 24 h pressures. No association was found when pain perception and blood pressure were correlated in the normotensive group. CONCLUSIONS: The correlation between both baseline and 24 h blood pressure and pain perception has been confirmed in a large group study of normotensive and hypertensive subjects. Moreover, even among the hypertensive range of blood pressure, the higher the blood pressure is, the lower the sensitivity to pain is. These findings strengthen the hypothesis of a role of the degree of blood pressure elevation in modulating pain sensitivity.

Effects of sustained-release isradipine on left ventricular anatomy and function in systemic hypertension.

With use of digitized M-mode echocardiograms and 24-hour noninvasive ambulatory blood pressure (BP) monitoring, the effects of chronic treatment with sustained-release isradipine on left ventricular (LV) morphology and function in hypertensive patients were evaluated. We selected 12 patients with LV hypertrophy and normal LV diastolic diameter. Echocardiograms and 24-hour BP monitoring were performed after 2 weeks of placebo and after 6 months of oral treatment with sustained-release isradipine (5 mg once daily). Therapy significantly reduced BP without changes in heart rate. LV mass decreased in all patients and peak lengthening rate of LV diameter, index of diastolic function, increased in all, with normalization in 7 of the 9 with basal diastolic impairment. Peak shortening rate of LV diameter, index of systolic function, was normal in all patients at basal evaluation and did not change after therapy. Reduction in LV mass significantly (p < 0.05) correlated with the decrease in average 24-hour and daytime systolic and diastolic BP. Sustained-release isradipine administered once daily is an effective antihypertensive agent; the drug also induces regression of LV hypertrophy, with significant improvement in LV diastolic function and no deterioration in systolic function.

Hyperinsulinemia, family history of hypertension, and essential hypertension.

The aim of this study was the evaluation of the relationships among hyperinsulinemia, a family history of hypertension, and essential hypertension. Insulin and C-peptide responses to an oral glucose load were studied in 175 lean normotensives (N) and untreated hypertensives (H) with (F+) and without (F-) a family history of hypertension: 30 NF-, 30 NF+, 45 HF-, and 70 HF+. The groups were comparable for age, sex, body mass index, and blood pressure. The following parameters were evaluated: plasma glucose (G), serum insulin (I), and C-peptide (Cp) before and 30, 60, 90, and 120 min after the glucose load, fasting glucose/insulin ratio (ISI), fasting insulin/C-peptide ratio (I/Cp), and 24-h ambulatory blood pressure monitoring. Plasma glucose was measured, fasting and during the test, and it and I/Cp were similar in the four groups. Serum insulin and Cp, both fasting and stimulated, were significantly higher and ISI lower in normotensives and hypertensives with hypertensive parents. Grouping the subjects first on the basis of blood pressure and then on the basis of family history, no differences were found between normotensives and hypertensives, whereas I and Cp, fasting and stimulated, were significantly higher and ISI lower in subjects with positive as compared to negative family history. The closest correlations between insulin and ambulatory blood pressure were found in normotensive with hypertensive parents; in hypertensives with hypertensive parents we only found a direct correlation between fasting Cp and nocturnal blood pressure fall; in hypertensives with normotensive parents insulin inversely correlated with nocturnal blood pressure fall. Insulin resistance seems to have a familial basis, independently of the presence of hypertension. Instead of showing a causal relationship between insulin resistance and hypertension, our results indicate that the two are partly independent components of a common familial pattern.

Relationship between left ventricular diastolic function and atrial natriuretic factor in never-treated mild hypertensives.

Using digitized M-mode echocardiograms, we evaluated the relationship between plasma atrial natriuretic factor (ANF) and morphofunctional characteristics of the left ventricle (LV) in 24 mild hypertensive men, never treated, with normal renal function. For each subject we collected a blood sample for plasma ANF evaluation and, immediately after, we recorded the LV echocardiogram. All the patients had normal LV diastolic diameter and systolic function; LV hypertrophy was present in 10 patients, 7 of whom had left atrial enlargement, and 13 patients had impaired LV diastolic function. ANF was similar between patients with and without LV hypertrophy, as well as between patients with and without left atrial enlargement, whereas ANF was significantly (P < .01) higher in patients with LV diastolic dysfunction than in patients with normal diastolic function. ANF was inversely correlated with both indices of diastolic function (peak lengthening rate and peak wall thinning rate), whereas it did not correlate with blood pressure, heart rate, end-systolic wall stress, and other LV parameters. In conclusion, from our results, ANF level in never-treated mild hypertensives is related neither to the degree of LV hypertrophy nor to the afterload, expressed as blood pressure or end-systolic wall stress, whereas it is mainly influenced by LV diastolic function: the diastolic impairment induces an increase in ANF level, probably through an increased atrial stretch.

Individualized versus standardized analysis of ambulatory blood pressure profile: relationship with left ventricular characteristics.

OBJECTIVE: Objective To determine whether the use of patients' individual awake/asleep patterns instead of fixed day/night intervals would influence the correlations between blood pressure values and left ventricular morpho-functional characteristics. METHODS: We enrolled 167 never-treated hypertensives (clinic blood pressures >160 mmHg systolic or 90 mmHg diastolic, or both): 32 had 24h blood pressures <130/80 mmHg [white-coat hypertensives (WCH)] and 135 had 24h blood pressures >130 mmHg systolic or 80 mmHg diastolic, or both (hypertensives). Each patient underwent left ventricular echocardiographic examination and 24h ambulatory blood pressure monitoring, evaluated twice, using standard day/night intervals (daytime 0700-2200 h, night-time 2200-0700 h) and using the patient's individual awake/asleep pattern (an individualized scheme). RESULTS: Daytime and night-time blood pressures in WCH and daytime and night-time diastolic blood pressures in hypertensives were not affected by choice of using individualized or standard intervals; daytime systolic blood pressure in hypertensives was significantly higher and night-time systolic blood pressure lower with individualized intervals. The non-dippers (nocturnal decrease in blood pressure <10% of daytime blood pressure) were 31 hypertensives and six WCH with standard day/night intervals and 25 hypertensives and four WCH with individualized intervals; nocturnal falls in systolic and diastolic blood pressures were significantly greater with individualized intervals for both groups. Left ventricular hypertrophy was present in 68 hypertensives and seven WCH; left ventricular systolic function was normal in all and left ventricular diastolic function was impaired in 53 hypertensives and seven WCH. Left ventricular characteristics of WCH were not correlated to blood pressure parameters; left ventricular mass index of hypertensives was directly correlated to 24h, daytime and night-time systolic blood pressures, whereas left ventricular diastolic function was inversely correlated to night-time systolic and diastolic blood pressures. The correlations were not affected by choice of using individual awake/asleep patterns. CONCLUSIONS: Timing day and night in an individualized way seems to improve the evaluation of nocturnal fall in blood pressure, but does not improve the ability to predict the left ventricle's involvement with ambulatory blood pressure monitoring.

Surgery in Crohn's disease: when, where and why the recurrences?

One frustrating feature in the surgical management of Crohn's disease is the high recurrence rate which may lead to reoperation. It is common opinion that relapses occur haphazardly both in time and in site, and the causes remain unknown. When does a recurrence really arise after surgery? Is the site of recurrence determined by definite causes? Is there a relapsing factor? Between 1965 and 1995, 177 patients underwent surgery for Crohn's disease. The procedures performed in 145 cases were those popular at the time, while a recent series of 20 selected patients was managed following a new approach based on epiploonplasty. This strategy stems from the strong conviction that Crohn's disease is not a primary bowel disease but the result of stasis and superimposed infection due to a primary hemolymphatic disorder of the mesentery. The five-year recurrence rate was 62% in patients operated on according to standard procedures, while no recurrences were reported in the epiploonplasty group. Among 12 remaining patients with recurrent disease, two cases are reported in detail because they provide evidence in favor of the hemolymphatic theory. This study also maintains that recurrences, viewed with the hemolymphatic disorder in mind, occur immediately after surgery, while the superimposed intestinal inflammatory process and stricturing events may appear clinically at different time intervals during follow-up. The site of recurrences usually corresponds to the mesenteric region subjected to compression. Altered mesenteric microcirculation appears to be the true essence of the disease.

Hepatic growths mimicking adrenal tumors.

BACKGROUND/AIMS: The upper district of the perirenal space is widely open and compliant, especially on the right side. Hepatic growths can, therefore, easily invade the adrenal gland area, mimicking adrenal tumors and vice-versa for adrenal and renal tumors. Data on the nature and exact origin of a mass in this region are important for appropriate preoperative management, surgical approach and prognosis but, sometimes, even modern imaging fails in this design. METHODOLOGY: The records and imaging documentation of 42 patients with a mass exceeding 6 cm in the hepatorenal space, have been retrospectively reviewed and compared with surgical and histological findings. RESULTS: Among the 14 patients with "non-functioning adrenal tumors," the preoperative diagnosis had been accurate in all but 2 cases where the suspected adrenal lesion turned out, intraoperatively, to be liver growths. These 2 cases are discussed in detail. CONCLUSIONS: The distinction between an intrahepatic and extrahepatic mass challenges modern imaging techniques, and even invasive procedures sometimes fail. A deceptive diagnosis may lead to inappropriate preoperative management and surgical procedures.

A new approach in the management of Crohn's disease: observations in 20 consecutive cases.

Although the "modern history" of Crohn's disease dates back to 1932, the etiology is still nebulous, the medical treatment inefficient and resective surgery results in a high recurrence rate. Twenty consecutive patients with terminal ileitis underwent ileo-cecal resection and mesenteric-epiploonplasty to enhance collaterals and lymphatic drainage. This approach was advised by experimental observations (the ligation of colonic lymphatic ducts in rabbits), by the intraoperative use of optics to better appreciate the details of the diseased bowel before and after injecting dye and by the angiographic results in one patient. In rabbit experiments, the obliteration of lymphatic drainage led to Crohn's disease-like macroscopic and microscopic patterns, while diffusion of the dye injected in the diseased segment showed altered lymph flow. The angiographic study in one patient confirmed the presence of vascular anomalies. Direct observation through optics revealed large vessels in the serosa with milky contents and the oozing of sticky exudate. In the 8 patients who underwent this procedure over 5 years ago, there were no recurrences. We strongly believe in the vasculo-lymphatic etiology of Crohn's disease and in mesentery-epiploonplasty as the only actual indirect approach to resolve hemolymphatic obstructions.

One-year antihypertensive treatment with amlodipine: effects on 24-hour blood pressure and left ventricular anatomy and function.

Using digitized M-mode echocardiograms and 24-hour noninvasive ambulatory blood pressure monitoring, we evaluated the effects of 1 year treatment with amlodipine on left ventricular morphology and function in 10 hypertensives with left ventricular hypertrophy. Echocardiograms and 24-hour blood pressure monitoring were performed after 3 weeks of wash-out and after 1 year of oral treatment with amlodipine (5 mg once daily). The therapy significantly lowered blood pressure, without changes in heart rate. Left ventricular mass decreased in all the patients and peak lengthening rate of left ventricular diameter, index of diastolic function, increased in all, with normalization in 5 of the 6 with basal diastolic impairment. Peak shortening rate of left ventricular diameter, index of systolic function, was normal in all at the basal evaluation and did not change after therapy. The percentage reduction of left ventricular mass index significantly correlated with percentage decrease of 24-hour and day-time systolic and diastolic blood pressure. Amlodipine is able to induce regression of left ventricular diastolic function and no changes of systolic function.

Ambulatory blood pressure, nocturnal blood pressure reduction and plasma catecholamines.

OBJECTIVE AND DESIGN: Controversial data have been reported on plasma catecholamines in hypertensives. Aims of this study were to find whether 24-hour ambulatory blood pressure was correlated with circulating catecholamines and to investigate whether nocturnal blood pressure reduction was associated with baseline plasma catecholamines. Samples for catecholamine determination were obtained in 34 consecutive male subjects after a 30-minute rest and before ambulatory blood pressure monitoring. RESULTS: Hypertensive patients (n = 22; 24-hour blood pressure: 145 +/- 14/94 +/- 6 mm Hg) showed similar norepinephrine and epinephrine levels when compared with normotensives (n = 12; 24-hour blood pressure: 124 +/- 6/81 +/- 6 mm Hg), and higher dopamine values (hypertensives: 64.6 +/- 58; normotensives: 26.2 +/- 31 pg/ml; p < 0.05). A positive correlation was observed between dopamine and diastolic nocturnal blood pressure (p < 0.05) while a negative correlation was found between dopamine and nocturnal diastolic blood pressure reduction (p < 0.025). No significant relationship was observed between both norepinephrine and epinephrine, and 24-hour blood pressures. CONCLUSIONS: Since previous reports have documented malfunctioning of dopaminergic system in hypertension, the higher levels of circulating plasma dopamine found in hypertensive patients in the present study may account for a peripheral compensatory increase. The correlation between dopamine and nocturnal blood pressure fall seems to indicate that the impairment of dopaminergic system may influence the 24-hour blood pressure profile, affecting the nocturnal blood pressure reduction.

Autonomic function and baroreflex sensitivity during angiotensin-converting enzyme inhibition or angiotensin II AT-1 receptor blockade in essential hypertensive patients.

OBJECTIVE: The influence of ACE-inhibition and angiotensin II ATI receptor blockade on the autonomic function and baroreflex sensitivity was investigated in hypertension. METHODS AND RESULTS: Heart rate variability was assessed in a resting condition by power spectrum analysis to evaluate the low frequency (LF) power, high frequency (HF) power and LF/HF ratio in 19 hypertensive patients and 23 normotensive controls. Moreover, the coherence between the tachogram and the systogram was evaluated, and the baroreflex gain (alphaLF-index), describing the transfer function of variability in the systolic pressure signal to variability in the RR interval, was obtained. Then a 24-h ambulatory blood pressure monitoring was performed. The 19 hypertensive patients were randomized to either enalapril or losartan treatment, and after 2 months were re-submitted to the RR variability and baroreflex study and to blood pressure monitoring. The subjects then crossed to the other antihypertensive treatment and were re-evaluated after an additional two months. No significant difference was found either in LF power and HF power and LF/HF ratio between normotensive and hypertensive subjects whereas a slight though significant difference was observed in the alphaLF-index. In hypertensive patients, both the treatments with enalapril and losartan reduced blood pressure and had no effect on heart rate. No significant change was observed in autonomic balance or in baroreflex sensitivity during the two antihypertensive treatments. CONCLUSIONS: In hypertensive patients, the angiotensin system or bradykinins do not seem to have any modulatory effect on the sympathetic/parasympathetic control of blood pressure and baroreflex sensitivity, in a resting condition. Since heart rates were unchanged by the two antihypertensive treatments despite a significant reduction of blood pressure, a resetting of baroreflex function was observed during both ACE-inhibition and angiotensin II ATI receptor blockade.

[Hydatid cysts of the ovary. Description of a case]. / Le cisti di echinococco dell'ovario. Descrizione di un caso.

Hydatid cysts of the ovary are rare lesions usually secondary to the rupture of an hepatic cyst. They may remain asymptomatic for long periods of time and may be discovered incidentally or cause irritation or compression symptoms. The history and whole abdomen echography consent diagnosis also based on the detection of the primary lesion. A case of hydatid cyst of the ovary is reported.

[Primary gastric lymphoma. Diagnostic and therapeutic considerations on 30 cases]. / Il linfoma gastrico primitivo. Considerazioni diagnostico-terapeutiche su 30 casi.

From 1987 to 1992, 30 cases of Primary Gastric Lymphoma were operated in the Institute of Patologia Speciale Chirurgica of the University of Bologna. Clinical features, diagnostic findings, therapeutic procedures and histologic characteristics are reported. The results are discussed after a brief literature review.

[Slowly reabsorbable suture threads in arterial microsurgery]. / Fili di sutura a lento riassorbimento in microchirurgia arteriosa.

Authors present the results of an experimental research to evaluate the effectiveness of a slow resorbable suture (Polyglactyn 910) in arterial microsurgery. Healing of vascular wall, histologically evaluated, showed good reliability, compared to other suture materials.

Components of arterial systolic pressure and RR-interval oscillation spectra in a case of baroreflex failure, a human open-loop model of vascular control.

The baroreflex control of circulation is always operating and modulates blood pressure and heart rate oscillations. Thus, the study of cardiovascular variability in humans is performed in a closed-loop model and the physiology of post-sinoaortic denervation is completely unknown in humans. We dissected for the first time the different components of systolic arterial pressure (SAP) and RR-interval spectra in a patient with 'baroreflex failure' (due to mixed cranial nerve neuroma) who represents a human model to investigate the cardiovascular regulation in an open-loop condition. Interactions among cardiovascular variability signals and respiratory influences were described using the multivariate parametric ARXAR model with the following findings: (1) rhythms unrelated to respiration were detected only at frequencies lower than classical low frequency (LF; Slow-LF, around 0.02 Hz) both in SAP an RR spectra, (2) small high-frequency (HF) modulation is present and related with respiration at rest and in tilt (but for SAP only) and (3) the Slow-LF fluctuations detected both in SAP and RR oscillate independently as the multivariate model shows no relationships between SAP and RR, and these oscillations are not phase related. Thus, we showed that in a patient with impaired baroreflex arc integrity the Slow-LF rhythms for RR have a central origin that dictates fluctuations on RR at the same rhythm but unrelated to the oscillation of SAP (which may be related with both peripheral activity and central rhythms). The synchronization in LF band is a hallmark of integrity of baroreflex arc whose impairment unmasks lower frequency rhythms in SAP and RR whose fluctuations oscillate independently.