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Biomedical subjects

A Matta

Publications and source records attributed to A Matta.

At least 19 recordsLinked to original sources
PubMed2000

Intra- and postoperative factors determining neurological complications after surgery under deep hypothermic circulatory arrest: a retrospective somatosensory evoked potential study.

OBJECTIVES: Intraoperative median nerve SEP monitoring uses the disappearance of cortical and brain stem activities as the criterion to determine that brain cooling is sufficient in deep hypothermic circulatory arrest (CA) surgery. This study presents the results of a retrospective SEP analysis of intraoperative events that engendered neurological complications. METHODS: Median nerve SEP monitoring was performed on 58 consecutive patients who underwent surgery under deep hypothermic CA. The monitoring was retrospectively analyzed and compared with intraoperative events, and postoperative symptoms. RESULTS: Intraoperative SEP abnormalities were observed in 9 out of the 16 patients who presented neurological complications. Among the 7 others, the abnormalities either were present preoperatively (n = 2), occurred postoperatively (n = 3) or only involved the lower limbs (n = 2). Although the mere inspection of the intraoperative SEPs was insufficient to determine the origin of the alterations, their comparison with intraoperative events facilitated the identification of hemodynamic factors in 7 cases and embolism in two cases. There were no patients in whom CA per se caused neurological complications. CONCLUSIONS: Intraoperative SEP monitoring helps identify intraoperative events responsible for neurological complications and prevent these in subsequent procedures. However, the neurological complications of deep hypothermic CA can also be due to pre- or postoperative factors that escape the domain of intraoperative monitoring.

Adolescent↗
PubMed1998

Use of the right gastroepiploic artery as a coronary artery bypass graft in 307 patients.

From October 1988 to October 1995 the right gastroepiploic artery was used as a conduit for coronary surgery in 307 patients. Their average age was 56.5 years (range 25-75) and 274 patients (89%) were male. Twenty-six cases (8.5%) were re-operations and 58 patients (19%) were operated upon on an urgent or semi-urgent basis. Target coronary vessels were the right coronary artery and its branches in 280 cases (91.4%), the circumflex artery in 25 cases (8%) and the left anterior descending artery in two cases. The right gastroepiploic artery was used as an in situ graft in 303 cases (98.7%) and as a free graft in 4 (1.3%). A total of 291 patients (94.8%) also received at least one mammary artery graft: both mammary arteries were used in 167 patients (54.4%). An average of 3.6 distal anastomoses were made per patient, three of them with arterial grafts. Eleven (3.2%) right gastroepiploic artery grafts were doubled with saphenous vein intraoperatively because of persistent myocardial ischemia. In-hospital mortality was 1.6% (five patients). Perioperative myocardial infarction occurred in twelve patients (3.9%). Follow-up now averages 26 months (range 6-88). There have been five late deaths (1.6%). A total of 265 (89.2%) patients are angina free. Of the total, 145 patients have been investigated with a maximal-stress test coupled with scintigraphy: residual myocardial ischemia was found in 10 patients, right gastroepiploic artery was related in three. Ninety-six patients have undergone angiographic restudy at a mean of 12 months (range 8-88) postoperatively. Patency of the right gastroepiploic artery grafts was 91.8%. This study confirms that the right gastroepiploic artery can be used as a conduit for coronary artery bypass surgery with minimal mortality or morbidity. Mid-term patency rates and clinical outcome are encouraging.

Adult↗
PubMed1998

[Sensitivity, specificity, and impact on the surgical strategy of the perioperative neuromonitoring of somatic evoked potentials in vascular surgery performed with circulatory arrest under deep hypothermia].

AIM: Median nerve somatosensory evoked potentials (SEP) monitoring performed in deep hypothermic circulatory arrest is useful in determining when brain cooling may sufficiently permit circulatory arrest, and to immediately indicate when brain injury occurs. The aim of this retrospective study, including 58 patients, is to determine SEP sensitivity, specificity and impact on the surgical strategy. METHOD: Sensitivity was determined on patients presenting new neurological complications. Specificity was measured on the patients without any new neurological defect. The impact of intraoperative SEP on the surgical strategy was determined when the occurrence of SEP alterations had provoked a modification of the surgical procedure. RESULTS: Five patients died intraoperatively due to non-neurological complications. Fourteen patients presented new neurological complications. SEP sensitivity reaches 64.3% when all the complications are included, but increases to 100% in our series if late postoperative complications, paraplegia and tibial posterior nerve lesion are excluded because median nerve SEP are not able to detect such complications. SEP monitoring was uneventful in the 39 patients whose did not present neurological complication: thus SEP specificity is absolute in our series. SEP had an impact on the surgical procedure whenever neurological complications due to hemodynamic disturbances occurred. CONCLUSION: This retrospective study shows the interest of intraoperative SEP as an useful tool for promptly identifying and preventing the neurological complication of hypothermic circulatory arrest.

Adolescent↗
PubMed1997

Somatosensory evoked potential monitoring in carotid surgery. I. Relationships between qualitative SEP alterations and intraoperative events.

This paper presents the results of intraoperative median nerve SEP monitoring in 205 successive patients undergoing isolated carotid endarterectomy (CE) (N = 172) or CE followed by coronary bypass (CBP) and/or vascular replacement (VR) (N = 33). The left and right median nerves were alternately stimulated and recordings performed on 4 channels: cervical, ipsi- and contralateral parietal, and frontal. SEPs were qualitatively rated in terms of mild, moderate, or severe ipsilateral, contralateral, or bilateral abnormalities. The SEP abnormalities were subdivided into 5 categories as a function of their relationships with intraoperative events: no alterations (67.3%), early or late SEP alterations after carotid cross-clamping (15.6%), SEP alterations after a drop in blood pressure (occurring outside of or within the cross-clamping period) (15.1%), SEP alterations of a most likely embolic origin (2.4%), SEP changes after head positioning (1%), and SEP changes after a modification of the anesthetic regimen (1.5%). Only moderate to severe SEP alterations occurring soon after carotid cross-clamping justified shunt installation in 16% of the cases. SEP alterations after a drop in blood pressure were reversed merely by restoring blood pressure. The neurological outcome was uneventful in 94.2% of cases. Of the 12 patients who developed neurological sequellae, only one case presented transient sequellae after isolated CE without SEP changes while most cases either had undergone combined CE and CBP and/or VR (6 cases) or had presented SEP alterations of embolic origin (3 cases). We conclude that our system of qualitative rating of SEPs proved very sensitive to intraoperative hemodynamic disturbances or macroembolisms.

Adult↗
PubMed1997

The usefulness of the spinal and subcortical components of the posterior tibial nerve SEPs for spinal cord monitoring during aortic coarctation repair.

This study examines how the recording of the lumbar and subcortical components of the posterior tibial nerve (PTN) SEPs may usefully replace that of cortical components in situations in which these components cannot be reliably obtained (infants, high concentrations of halogenated gasses). Lumbar, brain-stem, and cortical PTN SEPs were intraoperatively monitored in 7 patients undergoing repair of aortic coarctation under variable isoflurane concentration (up to 1.2%). Four patients were less than 1 year old. Two distinct activities were evidenced at the lumbar level in all of the patients: the dorsal root component (DRC) and the dorsal horn negativity (DHN). The equivalent of the adult P30 (lemniscal positivity; LP) was also present in all of the patients, whatever their age or the concentration of isoflurane. By contrast, the parietal activities were absent intraoperatively in the youngest patients. Spinal-cord ischemia consecutive to aortic cross-clamping gave rise to early DHN changes and later alterations of the LP in the two patients in which it occurred, while the DRC and the peripheral nerve activities remained unchanged. This elective sensitivity of the DHN is likely due to it being dependent on the gray matter of the spinal cord, the basal metabolism of which is greater than that of the white matter and to the situation of the DHN generator in a watershed zone of the spinal cord. This study emphasizes the interest of PTN SEPs for spinal-cord monitoring in vascular surgery and the importance of combining the recording of parietal activities with that of the lumbar spinal components.

Adult↗
PubMed1997

Ross procedure in congenital patients: results and left ventricular function.

METHODS: From April 1990 to August 1995, 121 patients (median age 42 years) underwent aortic valve replacement with allografts (69 patients) or autografts (52 patients). In this latter group, 24 Ross procedures have been performed in congenital patients since November 1991 (median age 10 years, range five months to 27 years): aortic incompetence (n = 17), isolated aortic stenosis (n = 5), small stenotic prosthesis (n = 2). Transthoracic echocardiography was obtained preoperatively in all patients and serially after surgery with the aim of measuring aortic and pulmonary annuli and evaluate gradients and incompetence and to study the left ventricular function. Intraoperative transoesophageal echocardiography was routinely used. Complete root replacement was performed in all patients. RESULTS: One patient died in the early postoperative period (4%). There was no late death. All survivors remained in NYHA class I and were free of complications and medications. No gradient nor any significant aortic incompetence could be demonstrated. In 17 patients with predominant aortic incompetence before surgery, the left ventricular function was followed prospectively, end-diastolic left ventricular dimensions diminished drastically from 2 +/- 3.4 S.D. above normal to -0.63 +/- 2.4 S.D. at one week postoperatively (day 10) to reach a normal value one to three months after surgery. Left ventricular mass remained abnormal at day 10 (from 4.7 +/- 3.3 S.D. to 5.3 +/- 3.8 S.D.) and diminished more progressively to reach a normal value (0.14 +/- 1.4 S.D.) at three months. This resulted in a significant decrease of end-systolic wall stress (-3.6 +/- 2.1 S.D.) and in a hyperdynamic function in the immediate postoperative days except in two patients. These two patients were characterized preoperatively by more severely dilated left ventricle (end diastolic dimension 5.3 +/- 0.03 versus 1.6 +/- 3 S.D.) with decreased left ventricular wall thickness (1.19 +/- 0.7 versus 3.44 +/- 1.9 S.D.), decreased ratio between end diastolic wall thickness and end diastolic dimension (0.14 +/- 0.06 versus 0.2 +/- 0.06) and a decreased velocity of shortening. Unlike the other 15 patients, the left ventricular function did not recover completely at mid term follow-up in those two patients. CONCLUSION: The Ross operation is a safe procedure and allows us to suppress completely the abnormal loading conditions of the left ventricle, resulting in a complete recovery of left ventricular function in most patients.

Adolescent↗
PubMed1997

Clinical evaluation of Duraflo II heparin treated extracorporeal circulation circuits (2nd version). The European Working Group on heparin coated extracorporeal circulation circuits.

OBJECTIVES: To evaluate whether the application of heparin treated circuits for elective coronary artery surgery improves postoperative recovery, a European multicenter randomised clinical trial was carried out. METHODS: In 11 European heart centers, 805 low-risk patients underwent cardiopulmonary bypass (CPB) with either an untreated circuit (n = 407) or an identical but heparin treated circuit (n = 398, Duraflo II). RESULTS: Significant differences were found among participating centers with respect to patient characteristics, blood handling procedures and postoperative care. The use of heparin treated circuits revealed no overall changes in blood loss, blood use, time on ventilator, occurrence of adverse events, morbidity, mortality, and intensive care stay. These results did not change after adjustment for centers and (other) prognostic factors as analysed with logistic regression. In both groups no clinical or technical (patient or device related) side effects were reported. Because female gender and aortic cross clamp time appeared as prognostic factors in the logistic regression analysis, a subgroup analysis with these variables was performed. In a subpopulation of females (n = 99), those receiving heparin treated circuits needed less blood products, had a lower incidence of rhythm disturbances and were extubated earlier than controls. In another subgroup of patients with aortic cross clamp time exceeding 60 min (n = 197), the amount of patients requiring prolonged intensive care treatment (> 24 h) was significantly lower when they received heparin treated circuits versus controls. CONCLUSION: These findings suggest that improved recovery can be expected with heparin treated circuits in specific higher risk patient populations (e.g. females) and when prolonged aortic cross clamp time is anticipated. Further investigations are recommended to analyses the clinical benefit of heparin treated circuits in studies with patients in different well defined risk categories and under better standardised circumstances.

Adult↗
PubMed1996

Multilevel somatosensory evoked potentials (SEPs) for spinal cord monitoring in descending thoracic and thoraco-abdominal aortic surgery.

The usefulness of somatosensory evoked potential (SEP) monitoring as a means of preventing paraplegia in descending aorta surgery was evaluated in 47 consecutive cases operated on for isthmic (14 cases), thoracic (22 cases), or thoraco-abdominal (11 cases) repair. An aortic dissection was found in 11 cases (acute in 6). Somatosensory evoked potentials were obtained by unilateral left and right posterior tibial nerve (PTN) stimulation at the ankle and recordings were performed on four channels: peripheral nerve, lumbar spinal, brain-stem, and cortical recordings. Our experience led to the following current strategy: the establishment of atrio(aorto)-femoral(aortic) bypass (29 cases), proximal and distal aortic cross-clamping, aortic repair with reimplantation of the culprit artery(ies) as indicated by SEP alterations. Five types of SEP alterations were defined on the basis of the neural level involved: type I (27.7% of cases) = distal spinal ischemia due to proximal aortic cross-clamping in the absence of bypass; type II (21.3%) = PTN ischemia due to left common femoral artery cross-clamping; type III (12.8%) = segmental spinal ischemia due to the exclusion of critical feeding arteries; type IV (4.3%) = ischemia in the left carotid artery territory; type V (4.3%) = global brain hypoperfusion due to systemic hypotension. Forty-five patients survived the operation and could be tested for neurological dysfunction. Three patients presented a postoperative spinal cord deficit, but this deficit was already present preoperatively in one case, so that the actual incidence of a new paraplegia in our series was 2/45 cases (4.4%). One of the two cases was clearly a delayed paraplegia with SEP alterations appearing several hours after the operation. Somatosensory evoked potentials were evaluated on the basis of their sensitivity, specificity, and impact on the surgical strategy. Regarding SEP sensitivity, we did not encounter any unexpected immediate paraplegia, but the critical factor appeared to be the duration of SEP absence due to spinal cord ischemia, which, according to the literature, should never exceed 30 min; after a longer absence, SEP return does not guarantee neurological recovery. Somatosensory evoked potential specificity was also 100%, but only 58% of the abnormalities found were actually consequent to spinal cord ischemia, the rest of the abnormalities being consequent to peripheral nerve or brain ischemia. Finally, SEP monitoring had a significant impact on surgical strategy in 19% of the cases. It is concluded that distal aortic perfusion and multilevel SEP monitoring play a significant role in preventing paraplegia in descending aorta surgery.

Adolescent↗
PubMed1996

Treatment of chancroid with azithromycin.

A randomized, comparative study undertaken in Nairobi, Kenya and a non-comparative evaluation undertaken in Carletonville, South Africa have both shown that a single oral dose of azithromycin 1 g is effective in the treatment of the genital ulcer disease (GUD), chancroid, with cure rates of 89% and 92% recorded respectively. While treatment failure was associated with human immunodeficiency virus seropositivity and lack of circumcision in Kenya, no such association could be found in the South African study. In both series, azithromycin treatment resulted in cure of both Haemophilus ducreyi culture-positive and culture-negative cases of GUD, including two cases subsequently diagnosed as lymphogranuloma venereum. A combination of single-dose azithromycin with single-dose benzathine penicillin may provide effective 'single-visit' syndromic treatment for GUD in many developing countries.

Anti-Bacterial Agents↗
PubMed1991

[Revision of midline sternotomies after cardiac surgery in 1988: retrospective study].

Twenty-three of 514 (4.6%) patients who underwent cardiac surgery in 1988 with cardiopulmonary bypass were later reoperated for sternal complications. Several risk factors, including pre-, intra and postoperative variables, have been investigated. A significant correlation was found with the presence of diabetes mellitus, the type of operation (bilateral internal mammary artery grafting), early reoperations, haemodynamic alterations, pulmonary infections and incidence of serious non infectious complications. The different sternal complications are analyzed from a clinical and therapeutic point of view.

Aged↗
PubMed1990

Surgical angioplasty of the left main coronary artery.

The conventional surgical treatment of isolated critical stenosis of the left main coronary artery restores a less physiologic perfusion of the myocardium, leads to occlusion of the left coronary ostium, and consumes an appreciable length of bypass material. Starting in June 1985, 23 surgical angioplasties have been performed in 22 patients. The left main stem was approached posteriorly in the first 11 patients, and an anterior approach was preferred in the last 12 because of better exposure. The onlay patch consisted of saphenous vein in the first 14 patients; pericardium was preferred in the last nine. The five failures occurred early. Four of these occurred in patients older than 60 years in whom calcifications of the left main stem had been seen on the preoperative angiogram. Eighteen procedures (78.3%) succeeded, but one patient (5.5%) died later of a massive air embolism. The 17 survivors are free of symptoms (maximal stress test combined with thallium scintigraphy) after a mean follow-up of 24.3 months. Angiographic restudy at an average of 8 months was obtained in 14 patients (82.3%) and revealed an excellent result in 13. In five patients, a late angiographic restudy (22 to 37 months) still revealed perfect patency of the left main stem. Provided that well-defined contraindications (calcifications, involvement of the distal bifurcation, older age) are respected, surgical angioplasty deserves a place in the array of surgical strategies.

Adult↗
PubMed1988

Should amiodarone be discontinued before cardiac surgery?

Between October 1985 and October 1986, 37 patients, chronically treated with amiodarone, underwent general anesthesia for cardiac, thoracic or vascular surgery. Among them, the 8 non-cardiac surgery patients showed neither intra-, nor postoperative complications. The 29 cardiac surgery patients, had various complications ranging from dysrhythmias (52%), sometimes necessitating a pacemaker (24%), to marked and even fatal vasoplegia. We describe the only fatal case and compare our complication rate with that described in the available literature. Most complications could be symptomatically treated. In addition, amiodarone has a very long elimination half-life: therefore withdrawal before surgery implies delaying operations by several weeks, and puts patients at increased risk of malignant dysrhythmias. However, fatal vasoplegia does occur, and its real incidence should be assessed by a broader survey.

Aged↗
PubMed1985

A safe alternative to awake intubation in neonates.

The authors present a retrospective study on the safety of their induction technique of anaesthesia in infants less than 30 days old. The records of 197 consecutive cases are reviewed, 47 of which concern major cardiac surgery. All the details of the technique are given: inhalation of halothane in O2 following a vagolytic premedication, spray of lidocaine 2 mg/kg on the vocal cords, orotracheal intubation to check adequacy of foreseen tube size, followed by definitive nasal intubation with the tube passed over a siliconed suction catheter. The results are discussed. The use of combined general and topical anaesthesia makes endotracheal intubation of the neonate nice and easy, atraumatic, well suited for training and more humane. Awake intubation should only be used as a resuscitative measure.

Anesthesia, General↗
PubMedDate not supplied

Ischemic complications of abdominal aortic surgery.

From 1982 through 1988, 634 consecutive patients underwent abdominal aortic reconstruction for occlusive (37%) or aneurysmal (63%) disease. We studied the ischemic problems affecting the branches of the aorta, excluding the coeliac and superior mesenteric arteries. Ischemic colitis (0.6%), spinal cord ischemia (0.16%), renal insufficiency (17%), and lower limbs ischemia (6.5%) were the major problems encountered. We identified the most significant factors associated with these complications such as hypotension, emergency, hypovolemia, preoperative renal function, suprarenal clamping, the quality of the preoperative investigation, and have suggested some specific preventive measures.

Adult↗
PubMedDate not supplied

Surgical treatment of subvalvular aortic stenosis. Long-term results.

From 1966 till May 1988, 53 patients underwent surgery for fixed subaortic stenosis. Subvalvular obstruction was isolated in 27 patients (Group I) and associated with aortic valve lesions in 26 (Group II). A membranous stricture was documented in 5 patients and a fibromuscular ring in 48. Excision of the ring and myectomy were performed in all patients, and an associated aortic valve replacement or reconstruction in 7 and 4 patients respectively. There were no hospital deaths. Follow-up evaluation in 50 patients ranged from 6 months to 22 years. Eight patients had to be reoperated upon (1 from group I, 7 from group II): aorto-ventriculoplasty was performed in 3, aortic valve replacement with redo myectomy in 3 and mitro-aortic valve replacement in 2. One of them had 2 reoperations. Functional status at the time of the last outpatient visit was most satisfactory. Continued evaluation remains necessary as obstruction may reappear despite the absence of symptoms.

Adolescent↗