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Biomedical subjects

F Giron

Publications and source records attributed to F Giron.

At least 19 recordsLinked to original sources

Bilateral subclavian artery aneurysms with pseudocoarctation of the aorta. Case report and review of the literature.

Subclavian artery aneurysms are rare. They occur predominantly on the right side. The most frequent cause of proximal subclavian artery aneurysm is atherosclerosis. An aneurysm of the left subclavian artery with normal origin is less common, and it is extremely rare when associated with an aortic coarctation. This report describes the first case of bilateral subclavian artery aneurysms associated with a pseudocoarctation of the aorta. Successful resection of the left subclavian artery aneurysms and the pseudocoarctation of the aorta was achieved using partial cardiopulmonary bypass.

Aneurysm

Arthroscopic-assisted anterior cruciate ligament reconstruction with the central third patellar tendon. A 5-8-year follow-up.

We reviewed 89 arthroscopically assisted patellar tendon anterior cruciate ligament (ACL) reconstructions for chronic isolated injuries with an average follow-up of 7 years (range 5.4 to 8.6 years). Pain was present in 7 knees (8%). Giving-way symptoms were reported by 7 patients (8%). A KT-2000 side-to-side difference over 5 mm at 30 lbs was recorded in 12 cases (16%). The pivot shift was glide in 17 cases (19%) and clunk in 10 (11%). A 3 degrees-5 degrees extension loss compared with the normal side was present in 20 knees (22%) and 6 degrees-10 degrees in 4 knees (4%). The intra-articular exit of the femoral tunnel was misplaced in the anterior 50% of the condyles along the roof of the notch in 10% of the knees. This positioning significantly (P = 0.003) increased the frequency of graft failure (62.5%) compared with the cases with a more posterior placement (graft failure 12%). An anterior position of the intra-articular exit of the tibial tunnel (in the anterior 15% of the sagittal width of the tibia) significantly (P = 0.01) increased the frequency of extension loss > 5 degrees. Medial meniscectomy was associated with a 35% incidence of narrowing of the medial joint space, which was significantly higher compared with knees with normal menisci (9%; P = 0.04) or with medial meniscal repair (7%; P = 0.05). In conclusion this study showed satisfactory anterior stability (KT-2000 side-to-side difference up to 5 mm and pivot absent or glide) in 83% of the knees. This percentage increases to 88% in the knees with a correct posterior and proximal femoral tunnel placement. Accuracy in tunnel positioning is essential for the success of ACL surgery. Meniscal repair was effective in decreasing joint space narrowing and should be attempted when possible.

Adolescent

Single-and dual-energy CT with monochromatic synchrotron x-rays.

We explored the potential for clinical research of computed tomography (CT) with monochromatic x-rays using the preclinical multiple energy computed tomography (MECT) system at the National Synchrotron Light Source. MECT has a fixed, horizontal fan beam with a subject apparatus rotating about a vertical axis; it will be used for imaging the human head and neck. Two CdWO4-photodiode array detectors with different spatial resolutions were used. A 10.5 cm diameter acrylic phantom was imaged with MECT at 43 keV and with a conventional CT (CCT) at 80 kVp: spatial resolution approximately equal to 6.5 line pairs (lp)/cm for both; slice height, 2.6 mm for MECT against 3.0 mm for CCT; surface dose, 3.1 cGy for MECT against 2.0 cGy for CCT. The resultant image noise was 1.5 HU for MECT against 3 HU for CCT. Computer simulations of the same images with more precisely matched spatial resolution, slice height and dose indicated an image-noise ratio of 1.4:1.0 for CCT against MECT. A 13.5 cm diameter acrylic phantom imaged with MECT at approximately 0.1 keV above the iodine K edge and with CCT showed, for a 240 micrograms I ml-1 solution, an image contrast of 26 HU for MECT and 13 and 9 HU for the 80 and 100 kVp CCT, respectively. The corresponding numbers from computer simulation of the same images were 26, 12, and 9 HU, respectively. MECT's potential for use in clinical research is discussed.

Acrylates

The Insall-Burstein posterior stabilized total knee replacement in the valgus knee.

Sixty-seven Insall-Burstein (Zimmer Inc, Warsaw, Indiana) posteriorly stabilized total knee replacements were implanted in knees with a preoperative alignment > 10 degrees of valgus (average: 19.5 degrees). An anteromedial approach with release of the lateral ligaments of the femur was used. A lateral patellar release was necessary in 49% of cases. Fifty-one knees (76%) were reviewed with an average follow-up of 6 years. Pain at follow-up was absent or mild in all of the knees except one with aseptic loosening of the tibial and patellar components. The average flexion was 105 degrees. The results according to the Knee Society Rating System were excellent in 53%, good in 39%, fair in 6%, and poor in 2%. A patellofemoral "clunk" was present in three knees (6%), and one knee required arthroscopic debridment. The mechanical axis was within 5 degrees of neutral in 88%. A survivorship analysis was performed using failure requiring reoperation as the end point. There were four failures due to aseptic loosening, symptomatic lateral ligamentous instability, deep infection, and recurrent patellar dislocation. The patellar component had not been implanted in the knee with recurrent patellar dislocation due to severe bony erosion. The cumulative success rate was 95% at 10 years. These results indicate that release of the contracted lateral structures and implantation of a posteriorly stabilized prosthesis achieve a stable and well-aligned knee in 66 out of 67 knees. Attention must be paid to patellar tracking and realignment of the extensor mechanism.

Adult

Intravenous leiomyomatosis.

Intravenous leiomyomatosis is a rare tumor in which benign smooth muscle cells grow into the pelvic venous channels of female patients. A case of intravenous leiomyomatosis with cardiac extension in a 45-year-old woman is described. The patient was diagnosed with cardiac syncope 3 months after total abdominal hysterectomy and was successfully treated with a two-stage approach consisting of sternotomy followed by laparotomy. The cause, disease, presentation, diagnosis, treatment and recurrence are reviewed.

Adolescent

Surgical treatment of recurrent dislocation of the patella.

Sixty-seven patients (69 knees) with recurrent patellar dislocation underwent either a lateral release (20 knees), a proximal realignment (14 knees), a distal realignment (16 knees), or a combined realignment (19 knees) procedure. Average respective followup was 8, 8, 6, and 4 years. Patients undergoing lateral release experienced a 40% recurrence of patellar dislocation. After a realignment procedure, redislocation was uncommon (4%), but pain and swelling were reported by 12% of the patients. Significant patellofemoral crepitation was present in 35% of the realignments. The congruence angle was corrected satisfactorily in the proximal realignments, but it remained abnormal in 25% of the distal realignments. The distance from the tuberosity to the sulcus was restored to normal by transposition of the tibial tuberosity, but remained abnormal in 36% of the proximal realignments. However, it did not preclude a good clinical result. Lateral release cannot be recommended for knees with severe dysplasia of the extensor mechanism. Proximal, distal, and combined realignments yielded similar clinical results. Retensioning of the medial structures and lateral release are effective in reducing the patella within the sulcus. Although transposition of the tuberosity is appealing, clinical advantages are less evident.

Adolescent

After the blue toe: prognosis of noncardiac arterial embolization in the lower extremities.

PURPOSE: To better understand the prognosis of atheroembolic disease, we reviewed the outcomes of 41 patients with embolization to the viscera and lower extremities. METHODS AND RESULTS: All cases involved emboli that originated from a radiographically identified proximal arterial source. There were 30 men and 11 women (mean age 65 years; mean follow-up time 2 years), and all had been first treated for this condition within the past 6 years. The overall mortality rate was 17% (7/41) and the rate of recurrent embolization 15% (6/41). To compare outcomes associated with supradiaphragmatic versus subdiaphragmatic disease, we defined two groups: group 1 comprised patients (n = 5) in whom the identified embolic source extended above the diaphragm, and group 2 comprised patients (n = 36) in whom the source remained below the diaphragm. The mortality rates in groups 1 and 2 were 60% (3/5) and 11% (4/36), respectively (p < 0.05). Recurrent embolization was also significantly higher in group 1 (60% vs 8%, p < 0.025). There were two amputations in group 1 and six in group 2 (p = not significant). Group 2 patients were then divided into two subgroups: those with limited disease (n = 19) in which the emboli had a single, radiographically identified source (i.e., aneurysm or single area of ulcerated plaque) and those with diffuse disease (n = 17) in which the emboli had multiple, radiographically identified potential sources. In the subgroup of patients with limited disease, no deaths or episodes of recurrent embolization occurred, whereas four deaths and three episodes of recurrent embolization occurred in the subgroup of patients with diffuse disease. The differences in these outcomes, however, were not statistically significant. Thirty selected patients (one from group 1 and 29 from group 2) underwent operation on or bypass of the imputed lesion. Only one (7%) of these 30 patients had recurrent embolization. In contrast, recurrent embolization was noted in four (36%) of the 11 patients who did not have an operation directed at the lesion (p < 0.025). No significant difference in mortality was found between patients who underwent operation and those who did not. CONCLUSIONS: Patients with atheroemboli have a substantial mortality rate and risk of recurrent embolization, especially if the disease process extends above the diaphragm; but in selected patients, operation may decrease the frequency of recurrence without increasing mortality.

Aged

Wound complications of the retroperitoneal approach to the aorta and iliac vessels.

Repeated complaints of postoperative wound pain prompted this review of 113 consecutive vascular operations involving a retroperitoneal approach to the aorta or iliac vessels or both. Flank muscle-splitting incisions (n = 53) had been used to approach the terminal aorta or iliac arteries. Two types of muscle-dividing incisions had also been used: incisions through the eleventh intercostal space (n = 41) to approach the infrarenal aorta; and incisions through the eighth, ninth, or tenth intercostal space with division of the diaphragm (n = 19) to approach the suprarenal aorta. Data on incisional pain, lumbosacral neuritic pain, incisional hernia, and deforming abdominal bulge were culled from the records of follow-up examinations conducted on all patients during periods ranging from 2 to 48 months. Both types of muscle-dividing incisions used to expose the aorta were associated with a 23% (14/60) incidence of abdominal bulge, a 7% (4/60) incidence of incisional hernia, and, more important, a 37% (22/60) incidence of prolonged disabling pain. Thus, although retroperitoneal exposure may be the preferred or the safest approach to certain aortic lesions, its routine use via muscle-dividing incisions is not recommended when the proposed operation can be carried out equally well by the conventional midline transperitoneal approach.

Aorta, Abdominal

Complications of percutaneous intra-aortic balloon pump use in patients with peripheral vascular disease.

Percutaneous intra-aortic balloon pump use may carry an increased risk for patients with peripheral vascular disease. To determine the incidence and types of associated complications, the medical records of 144 patients who underwent a total of 153 percutaneous intra-aortic balloon pump insertions were reviewed. Patients were divided into two groups. Group 1 was composed of 20 patients with a history of peripheral vascular disease. Group 2 was composed of 124 patients without such history; they underwent a total of 133 insertions. Nineteen major complications (12%) occurred, 12 in group 1 (60% of 20 insertions) and seven in group 2 (5% of 133 insertions). Major complications were further classified by their nature: embolic, occlusive, and technical. All three types of complications occurred more frequently in group 1. Embolic complications occurred more frequently in patients with aneurysms and proved the most lethal, with two of six deaths in group 1 resulting from this complication.

Aneurysm

Indirect measurement of systolic blood pressure in the rabbit.

Long-term studies of rabbit blood pressure require a reliable method for repeated blood pressure measurements. Ideally, this method would be simple, noninvasive, and accurate over the range of anticipated blood pressures. To facilitate our own studies of rabbit carotid artery graft patency, we have developed a technique for the indirect measurement of systolic blood pressure in the rabbit that utilizes a photoplethysmograph sensor placed distal to an inflatable air bladder positioned over the central ear artery. We have compared measurements obtained with this method to direct measurements of aortic pressure and found a linear correlation.

Animals

Techniques for experimental rat kidney (and liver) perfusion.

The technique described here allows to perfuse in situ either the left kidney alone, both kidneys or both kidneys and the liver of rats with few operations, without danger of organs damage and with a good control of temperature and pressure. This technique allows a good maintainance of the metabolic activity of the perfused tissues and offers the possibility to collect urine by cannulating the bladder.

Animals

Mesenteric blood flow in patients with diabetic neuropathy.

We examined flow velocities in the superior mesenteric artery and celiac artery in normal controls (group C, n = 11), diabetic patients (group D, n = 8), and diabetic patients with clinically evident autonomic neuropathy (group DN, n = 6) to further define the usefulness of duplex examination in the evaluation of the mesenteric circulation in normal and disease states. By use of a 3 MHz duplex scanner, peak systolic velocity, peak diastolic forward velocity, end-diastolic forward velocity, and peak diastolic reverse velocity were measured in centimeters per second before and after a standardized meal. The vessels' diameters in centimeters were also measured. After the meal peak diastolic reverse velocity disappeared in all patients. The average vessel diameter in the superior mesenteric artery (0.7 cm) and celiac artery (0.8 cm) did not change. Flow velocities in the celiac artery were not significantly altered by the meal. In the control group, peak systolic velocity in the superior mesenteric artery increased 38%, peak diastolic forward velocity rose 66%, and end-diastolic forward velocity increased by 70%. In the diabetic nonneuropathic group the changes were 15%, 98%, and 100%, respectively. These changes were statistically significant (p less than 0.01). On the other hand, the patients with diabetic autonomic neuropathy presenting a picture of gastroparesis did not exhibit the expected increases in postprandial velocities. Moreover, this alteration in blood flow velocity, although similar to that encountered in patients with intestinal angina, did not appear to be due to occlusive arterial disease on the basis of clinical examination and B-mode scanning.

Autonomic Nervous System Diseases

Transaortic endarterectomy of renal visceral artery lesions in association with infrarenal aortic surgery.

The complexity of infrarenal aortic reconstruction increases when bypass grafts to revascularize associated renal and visceral arteries are needed. Lesions in these vessels, however, are usually limited to their aortic orifices and therefore are amenable to retroperitoneal transaortic endarterectomy. A combined infrarenal aortic reconstruction and transaortic endarterectomy of the renal/visceral vessels was used in 18 (16%) of 120 patients undergoing elective infrarenal aortic reconstruction over a 2-year-period. Transaortic endarterectomy was performed primarily for renal preservation in 11 patients with bilateral, high-grade renal artery stenoses and abnormal renal function (serum creatinine greater than or equal to 1.9 mg/dl). In seven patients transaortic endarterectomy was performed as a secondary procedure during the course of complex reconstruction of aneurysmal or occlusive aortic disease. Mean serum creatinine, which was elevated preoperatively in 14 (78%) patients (3.3 mg/dl), decreased significantly after the operation (2.0 mg/dl, p less than 0.01). A single death occurred in the 18 patients undergoing transaortic endarterectomy. Renal function preservation can be achieved by renal revascularization in patients with bilateral renal artery stenoses and decreased renal function. The retroperitoneal approach to aortic reconstruction and the use of transaortic endarterectomy allows correction of most renal/visceral vessel involvement in complex aortic revascularization procedures.

Aorta, Abdominal

The value of computed tomography in the management of symptomatic abdominal aortic aneurysms.

The use of computed tomographic (CT) scanning in the diagnosis of ruptured abdominal aortic aneurysm is controversial because the delay created by the procedure, it has been argued, may increase overall mortality. However, if emergency surgery can be avoided in the medically compromised patient, surgical results may improve. To assess the value of CT scanning, we studied the 1983 to 1988 records of 65 hemodynamically stable patients with abdominal aortic aneurysms, who underwent diagnostic CT scanning for acute abdominal or back pain. Twenty-one patients had a history of severe cardiac, renal, or pulmonary disease. The average duration of the examination was 63 minutes; no episodes of hypotension occurred. Subsequently, 17 of 18 patients with ruptured aneurysms had emergency surgery, with 31% morbidity and 29% mortality. Of 44 patients found to have nonruptured aneurysms, 13 had other causes for their pain, nine were not considered surgical candidates, and 24 had elective aneurysmectomies, with 8% morbidity and 0% mortality. In three patients CT scanning excluded the diagnosis of aneurysm. Additional information provided by CT scanning enhanced the safety of the perioperative management of four patients with rupture and 14 without. In conclusion, the delay imposed by obtaining a preoperative CT scan in patients with possible ruptured aneurysm did not adversely affect patient outcome, and the information obtained from it aided significantly in both preoperative and intraoperative management.

Aorta, Abdominal

Energetic behaviour of mitochondria isolated from rat livers perfused with a perfluorodecalin + N,N-perfluorodiethylcyclohexylamine emulsion.

Rat livers have been perfused with a saline control medium or with a perfluorocarbon emulsion containing perfluorodecalin and N,N-perfluorodiethylcyclohexylamine, and the respiratory rates and transmembrane electrical potentials of mitochondria isolated following perfusion have been evaluated. The results indicate that the perfluorocarbon emulsion used, by providing a good oxygen supply to the perfused liver, allowed to preserve the efficiency of mitochondrial oxidative phosphorylation.

Adenosine Triphosphate

The early and late responses of the arterial wall to graft placement.

The relationship between the early smooth muscle cell proliferative response (SMC-PR) to injury and the later development of myointimal hyperplasia (MIH) complicating arterial bypass grafts remains unclear. In the present study, the early SMC-PR and the later MIH induced by a 2-mm-diameter PTFE graft placed in a rabbit carotid were compared with the response induced by an autogenous artery (AA) graft in the contralateral carotid. The early SMC-PR was measured in the proximal and distal arterial segments 5 days after graft placement by in vivo labeling with [3H]thymidine to determine the DNA specific activity (DNA-SA). The later anastomotic MIH was measured 16 and 32 weeks postgrafting by calculating the intimal/medial ratio. There was a marked and similar increase in the early SMC-PR noted with both the AA and the polytetrafluoroethylene (PTFE) grafts. The distal segments demonstrated a significantly higher DNA-SA when compared to the proximal in both AA- and PTFE-grafted arteries. There was a moderate degree of anastomotic MIH noted in chronic grafts; however, a regression in intimal thickening was observed over time in the AA-grafted arteries, while the distal anastomosis of the PTFE-grafted vessels demonstrated a continuous progression of the MIH process. The early SMC-PR may abate in arteries grafted with autogenous grafts, but there is a persistent proliferative response at the distal anastomosis associated with synthetic grafts.

Animals