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Biomedical subjects

R Casanova

Publications and source records attributed to R Casanova.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Contribution of transcranial Doppler sonography to the diagnosis of brain death in children].

Brain death can be characterized by cessation of cerebral blood flow. We have measured blood flow velocity in cerebral arteries of 17 comatous children with a transcranial pulsed Doppler equipment. In 11 children who progressed to brain death, we have recorded a progressive decrease of Doppler signal with the following steps: decrease of diastolic velocity, no diastolic velocity, reverse diastolic flow, decrease of systolic signal, no signal at all. In the 6 surviving children (all except one with severe deficits), after an initial reduction but never to a retrograde flow, arterial cerebral blood flow velocity increased to high diastolic values before normalization. Transcranial Doppler technique is non invasive, reliable, can be used at the bedside and repeated; it allows evaluating the cerebral blood flow in comatous children and represents a useful adjunct to brain death diagnosis.

Brain Death↗
PubMed1990

Response of patients with hemophilia A and von Willebrand disease to desmopressin (DDAVP).

Factor VIII (FVIII) response to desmopressin (deamino-8-D-arginine vasopressin, abbreviated DDAVP) was studied in patients with mild Hemophilia A and von Willebrand Disease (vWD) who attend our Hemophilia Clinic. Thirty eight children and 9 adults had their F VIII components assayed 60 minutes after intravenous (IV) administration of DDAVP, 0.35 microgram/kg. Among 27 hemophiliacs, F VIII coagulant activity (F VIII: C) increased from a mean of 16.8 to 59.2 u/dL; with an average 3.2-fold increase. In 20 vWD patients, the mean F VIII:C and von Willebrand Factor increased from a mean of 50.1 to 136%; and from 22.6 to 75.6%; with an average 3.0 and 5.7-fold increase, respectively. The overall F VIII:C response was good or excellent in 81.5% of the hemophiliacs, and in 89.5% of the vWD patients tested. No significant side effects were observed. This study has demonstrated that IV DDAVP can cause an increase of F VIII:C and vWF to hemostatic levels, and thus it may be useful for the control of bleeding episodes in most of the patients tested in our clinic.

Adult↗
PubMed1990

Therapy for pediatric aplastic anemia; 7 years experience at the Puerto Rico Pediatric Oncology Program.

Nine pediatric patients with aplastic or hypoplastic anemia were seen at the Pediatric Hematology-Oncology service of the University of Puerto Rico, from 1980 to first trimester of 1987. Included were eight males and one female ranging from twenty months to sixteen 8/12 years (mean 13 years). Hematomas and fever were the most common complaints. The interval since the first symptoms and the diagnosis varied from one day to one week. The peripheral cell count was abnormal in all patients; pancytopenia being the most common finding. Five of seven who received antithymocyte globulin (ATG-AM), showed improvement in their peripheral count. The median time interval from the end of ATG-AM and response was two months (range 2 weeks to 15 months).

Adolescent↗
PubMed1989

Sutured retropupillary posterior chamber intraocular lenses for exchange or secondary implantation. The 12th annual Binkhorst lecture, 1988.

The histopathologic findings of four eyes obtained postmortem with iris-sutured posterior chamber intraocular lenses (PC IOLs) are described. These IOLs were implanted as exchange procedures. In most instances, the loops were not situated in the ciliary sulcus but rather were suspended behind the iris and ciliary body. Therefore, the primary mechanism of fixation of iris-sutured PC IOLs appears to be the sutures themselves rather than adherence to the ciliary tissues. This report of four eyes is preliminary, but the pathologic analysis, showing few significant lesions attributable to the IOL, provides a reason for optimism for using this technique. A long-term clinical study comparing the results of sutured PC IOLs with those of anterior chamber IOLs (AC IOLs) used in secondary or exchange implantation, as well as collection and analysis of more pathologic specimens, should provide a more definitive answer as to the preferred procedure.

Aged↗
PubMed1989

[Myocardial scintigraphy using 201-thallium and 2-dimensional echocardiogram after dipyridamole infusion in the early evaluation of post-infarct residual ischemia].

Dipyridamole thallium scintigraphy (TI-DP) and dipyridamole two-dimensional echocardiography (Echo-DP) were performed on 38 patients (pts), 11 +/- 4 days after acute myocardial infarction. Our study intends to assess whether or not imaging methods are useful both in identifying residual jeopardized myocardium and in selecting pts for coronary angiography. No serious side effects were induced during the DP test. In 11 pts angina was not induced, worsening of wall motion abnormalities was not detected on Echo-DP; no reversible defects were found on TI-DP. The remaining 27 pts who showed transient defects on TI-DP underwent coronary angiography. All pts had either multivessel coronary disease or severe single-vessel disease and myocardial revascularisation was performed in all of them. Of these 27 patients, only 5 suffered angina and showed ST-T depression; only in 15 dyskinetic wall motion development was detected on Echo-DP. Finally we can conclude: the DP-test can be safely performed in the early post-infarction period; both the reported imaging methods enable the identification of jeopardized myocardium even if with different ranges of sensitivity; pts negative to both TI-DP and Echo-DP can be safely followed without coronary angiography; pts with transient defects on TI-DP can be reasonably referred to coronary angiography.

Adult↗
PubMed1988

Clinical evaluation of flap viability with a dermal surface fluorometer.

A dermal surface fluorometer was used to monitor vascular perfusion in 22 patients who underwent reconstructive surgical procedures with a variety of flaps (e.g., skin flaps, musculocutaneous flaps, fasciocutaneous flaps, and Z-plasties). Sodium fluorescein (1.5 mg per kilogram of body weight) was administered intravenously at the completion of the operative procedure. Quantitative fluorescence readings were obtained at different points in each flap by means of the surface fluorometer (Fluoroscan). The readings were taken at several time intervals and compared with those of normal skin (control). A perfusion ratio was determined in each case according to the following formula: flap reading/(normal skin control reading X 100). Partial necrosis occurred in 4 patients, correlating with low fluorescein perfusion measurements. From our findings, it appears that a perfusion ratio of 15% or greater 10 minutes following injection will accurately predict tissue viability. No systemic reactions were observed in these patients. We believe that this minimally invasive technique should be of considerable assistance in the postoperative evaluation of flap viability.

Adult↗
PubMed1987

Microarterial sutureless sleeve anastomosis using a polymeric adhesive: an experimental study.

A new technique for microarterial sutureless anastomosis that involves telescoping one vessel into the other and placing a microdrop of a polymeric adhesive (iso-propyl-cyanoacrylate) is described. Sixty-six anastomoses were performed in rat femoral arteries with a patency rate of 95 percent. Light and electron microscopic studies were conducted at regular intervals, starting immediately to 90 days postoperative. From this experimental study, it appears that the described method of anastomosis is faster and easier to perform and at least as reliable as the conventional end-to-end suture anastomosis. In addition, it was observed that tissue reaction to the glue remained primarily adventitial and did not disturb vessel patency.

Animals↗
PubMed1986

Craniofacial reconstruction after tumor resections using vascularized outer table calvarial bone flaps.

The outer table of calvarium is a useful donor site for facial reconstruction after resection of tumors. Large defects, especially when associated with multiple operations and radiotherapy, are poor recipient beds for nonvascularized bone grafts. A technique for the transfer of vascularized outer table has been developed and used in 11 patients for reconstruction of tumor defects. Satisfactory correction of both functional and esthetic problems has been achieved with satisfactory long-term stability and low morbidity.

Adolescent↗
PubMed1986

Anatomic basis for vascularized outer-table calvarial bone flaps.

The vascularization of the scalp and calvarium was studied in cadavers to better define the design of vascularized split- or full-thickness calvarial bone flaps. Selective dye injections of the superficial temporal and internal maxillary arteries established a horizontal and vertical network of vessels within and between each layer of the scalp. The periosteum of the frontoparietal region continues over the temporal aponeurosis as a separate, distinct layer, the innominate fascia, which is irrigated by numerous proximal branches of the superficial and deep temporal arteries. The periosteum can sustain the outer table of the calvarium by means of multiple small, vertical perforators. Between the periosteum and the outer table is a thin areolar layer of subperiosteum which continues beneath the temporal muscle. We feel that vascularized outer-table calvarial flaps can safely be pedicled using only the temporal aponeurosis, innominate fascia, and periosteum without including the galea or temporal muscle.

Blood Vessels↗
PubMed1986

Vascularized outer-table calvarial bone flaps.

Based on an anatomic study of the vascularization of the calvarium in cadavers, a technique for the transfer of vascularized outer-table calvarial bone has been developed. The outer table of the calvarium receives numerous small perforators from its overlying periosteum. The periosteum is continuous with a distinct fascial layer overlying the temporal aponeurosis which we have termed the innominate fascia. Because of a network of anastomosing vessels from proximal branches of the superficial temporal artery and perforating branches of the deep temporal artery, the outer table of the calvarium can be carried on a pedicle which contains the temporal aponeurosis, innominate fascia, and periosteum. Thirty-seven vascularized outer-table calvarial bone flaps have been performed for a variety of craniofacial reconstructive deformities. Remarkable stability and lack of resorption have led the authors to favor this method of reconstruction particularly in poorly vascularized or previously infected recipient beds.

Adolescent↗
PubMed1986

The value of computed tomography in the localization of undescended testes.

Eight patients with unilateral and four with bilateral (4) unpalpable testes were evaluated with CT for localization. All patients were later submitted to laparascopy and/or surgery and 13 cryptorchid testes and 3 atrophic or agenesic testes were found. CT detected correctly 11 of the cryptorchid testes - (85%) with one false positive and one false negative finding. In the three atrophic or agenesic testes, CT did not identify any image suspicious of being a testis, so there three were no false positive studies here. It is concluded that CT is an accurate noninvasive method for the preoperative detection of cryptorchid testes.

Adolescent↗
PubMed1985

Myocutaneous and fasciocutaneous flaps in the upper limb.

The vascular supply to the upper limb is reviewed and several specific myocutaneous and fasciocutaneous flaps are discussed. Also considered is specific coverage of defects in the shoulder, scapula, humerus, elbow, and radial or ulnar bones.

Arm↗
PubMed1983

CT findings in Mirizzi syndrome.

Six cases of Mirizzi syndrome have been studied by computed tomography (CT). Although not specific, CT frequently reveals an irregular cavity near the gallbladder neck and calculi outside the viscus. Emphasis is placed on the possibility of recognizing this entity by CT prior to surgery.

Aged↗
PubMed1983

Anatomy of the upper abdomen: computarized tomography.

The possibilities of computed axial tomography in displaying normal anatomy are shown. The fact scanners are able to show important anatomical details including vascular anatomy. The upper abdomen is shown in consecutive slices to demonstrate the most important anatomical landmarks. The possibility of reconstructed coronal and sagittal planes from the axial slices offers good correlation with classical topographical anatomy. Axial anatomy from cadaver and computed tomography should be included in our teaching to medical students as part of the background needed for their future clinical practice.

Abdomen↗