(1/2176) Wasting of the small hand muscles in upper and mid-cervical cord lesions.
Four patients are described with destructive rheumatoid arthritis of the cervical spine and neurogenic wasting of forearm and hand muscles. The pathological connection is not immediately obvious, but a relationship between these two observations is described here with clinical, radiological, electrophysiological and necropsy findings. Compression of the anterior spinal artery at upper and mid-cervical levels is demonstrated to be the likely cause of changes lower in the spinal cord. These are shown to be due to the resulting ischaemia of the anterior part of the lower cervical spinal cord, with degeneration of the neurones innervating the forearm and hand muscles. These findings favour external compression of the anterior spinal artery leading to ischaemia in a watershed area as the likeliest explanation for this otherwise inappropriate and bizarre phenomenon. (+info)
(2/2176) Investigation of distal aortic compliance and vasodilator responsiveness in heart failure due to proximal aortic stenosis in the guinea pig.
Hypotension and syncope are recognized features of chronic aortic stenosis. This study examined vasomotor responses and dynamic compliance in isolated abdominal aortae after chronic constriction of the ascending aorta. Guinea pigs underwent constriction of the ascending aorta or sham operation. Sections of descending aorta were removed for studies of contractile performance and compliance. Dynamic compliance was measured using a feedback-controlled pulsatile pressure system at frequencies of 0.5, 1.5 and 2.5 Hz and mean pressures from 40 to 100 mmHg. Chronic (149+/-6 days) aortic constriction resulted in significant increases in organ weight/body weight ratios for left ventricle (58%), right ventricle (100%) and lung (61%). The presence of heart failure was indicated by increased lung weights, left ventricular end-diastolic pressure and systemic vascular resistance, reduced cardiac output and increased levels of plasma atrial natriuretic peptide (166%), adrenaline (x20), noradrenaline (106%) and dopamine (x3). Aortic rings showed similar constrictor responses to phenylephrine and angiotensin II, but maximal vasodilator responses to acetylcholine and isoprenaline were significantly increased (144% and 48% respectively). Dilator responses to sodium nitroprusside, forskolin and cromokalim were unchanged. Compliance of all vessels decreased with increasing pulsatile frequency and to a lesser extent with increased mean pressure, but were similar in aortic-constricted and control groups. Chronic constriction of the ascending aorta resulted in heart failure and increased vasodilator responses to acetylcholine and isoprenaline in the distal aorta while dynamic compliance was unchanged. We hypothesize that increased endothelium-mediated vasodilatation may contribute to hypotension and syncope in patients with left ventricular outflow obstruction. (+info)
(3/2176) Prenatal features of ductus arteriosus constriction and restrictive foramen ovale in d-transposition of the great arteries.
BACKGROUND: Although most neonates with d-transposition of the great arteries (TGA) have an uncomplicated preoperative course, some with a restrictive foramen ovale (FO), ductus arteriosus (DA) constriction, or pulmonary hypertension may be severely hypoxemic and even die shortly after birth. Our goal was to determine whether prenatal echocardiography can identify these high-risk fetuses with TGA. METHODS AND RESULTS: We reviewed the prenatal and postnatal echocardiograms and outcomes of 16 fetuses with TGA/intact ventricular septum or small ventricular septal defect. Of the 16 fetuses, 6 prenatally had an abnormal FO (fixed position, flat, and/or redundant septum primum). Five of the 6 had restrictive FO at birth. Five fetuses had DA narrowing at the pulmonary artery end in utero, and 6 had a small DA (diameter z score of <-2.0). Of 4 fetuses with the most diminutive DA, 2 also had an abnormal appearance of the FO, and both died immediately after birth. One other fetus had persistent pulmonary hypertension. Eight fetuses had abnormal Doppler flow pattern in the DA (continuous high-velocity flow, n=1; retrograde diastolic flow, n=7). CONCLUSIONS: Abnormal features of the FO, DA, or both are present in fetuses with TGA at high risk for postnatal hypoxemia. These features may result from the abnormal intrauterine hemodynamics in TGA. A combination of restrictive FO and DA constriction in TGA may be associated with early neonatal death. (+info)
(4/2176) Surgical transluminal iliac angioplasty with selective stenting: long-term results assessed by means of duplex scanning.
PURPOSE: The safety of iliac angioplasty and selective stenting performed in the operating room by vascular surgeons was evaluated, and the short- and long-term results were assessed by means of serial duplex scanning. METHODS: Between 1989 and 1996, 281 iliac stenotic or occlusive lesions in 235 consecutive patients with chronic limb ischemia were treated by means of percutaneous transluminal angioplasty (PTA) alone (n = 214) or PTA with stent (n = 67, 23.8%). There were 260 primary lesions and 21 restenosis after a first PTA, which were analyzed separately. Stents were implanted in selected cases, either primarily in totally occluded arteries or after suboptimum results of PTA (ie, residual stenosis or a dissection). Data were collected prospectively and analyzed retrospectively. Results were reported in an intention-to-treat basis. Clinical results and patency were evaluated by means of symptom assessment, ankle brachial pressure index, and duplex scanning at discharge and 1, 3, 6, and every 12 months after angioplasty. To identify factors that may affect outcome, 12 clinical and radiological variables, including the four categories of lesions defined by the Standards of Practice Committee of the Society of Cardiovascular and Interventional Radiology, were analyzed separately. The statistical significances of life-table analysis of patency were determined by means of the log-rank test. RESULTS: There were no postoperative deaths or amputations. Local, general, and vascular complications occurred in 2.1%, 1.3% and 4.7% of cases, respectively (total, 8.1%). The mean follow-up period was 29.6 months. The cumulative patency rates +/- SE of the 260 PTAs (including 55 PTAs plus stents) were 92.9% +/- 1.5% at 1 month, 86. 5% +/- 1.7% at 1 year, 81.2% +/- 2.3% at 2 years, 78.8% +/- 2.9% at 3 years, and 75.4% +/- 3.5% at 5 and 6 years. The two-year patency rate of 21 redo PTAs (including 11 PTAs plus stents) was 79.1% +/- 18.2%. Of 12 predictable variables studied in the first PTA group, only the category of the lesion was predictive of long-term patency. The two-year patency rate was 84% +/- 3% for 199 category 1 lesions and 69.7% +/- 6.5% for 61 category 2, 3, and 4 lesions together (P =. 02). There was no difference of patency in the stented and nonstented group. CONCLUSION: Iliac PTA alone or with the use of a stent (in cases of occlusion and/or suboptimal results of PTA) offers an excellent long-term patency rate. Categorization of lesions remains useful in predicting long-term outcome. PTA can be performed safely by vascular surgeons in the operating room and should be considered to be the primary treatment for localized iliac occlusive disease. (+info)
(5/2176) Plaque area increase and vascular remodeling contribute to lumen area change after percutaneous transluminal angioplasty of the femoropopliteal artery: an intravascular ultrasound study.
OBJECTIVE: The aim of the study was to assess the change in lumen area (LA), plaque area (PLA), and vessel area (VA) after percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery. METHODS: This was a prospective study. Twenty patients were studied with intravascular ultrasound (IVUS) immediately after PTA and at follow-up examination. Multiple corresponding IVUS cross-sections were analyzed at the segments that were dilated by PTA (ie, treated sites; n = 168), including the most stenotic site (n = 20) and the nondilated segments (ie, reference sites; n = 77). RESULTS: At follow-up examination, both the PLA increase (13%) and the VA decrease (9%) resulted in a significant LA decrease (43%) at the most stenotic sites (P =.001). At the treated sites, the LA decrease (15%) was smaller and was caused by the PLA increase (15%). At the reference sites, the PLA increase (15%) and the VA increase (6%) resulted in a slight LA decrease (3%). An analysis of the IVUS cross-sections that were grouped according to LA change (difference >/=10%) revealed a similar PLA increase in all the groups: the type of vascular remodeling (VA decrease, no change, or increase) determined the LA change. At the treated sites, the LA change and the VA change correlated closely (r = 0.77, P <.001). At the treated sites, significantly more PLA increase was seen in the IVUS cross-sections that showed hard lesion or media rupture (P <.05). No relationship was found between the presence of dissection and the quantitative changes. CONCLUSION: At the most stenotic sites, lumen narrowing was caused by plaque increase and vessel shrinkage. Both the treated sites and the reference sites showed a significant PLA increase: the type of vascular remodeling determined the LA change at follow-up examination. The extent of the PLA increase was significantly larger in the IVUS cross-sections that showed hard lesion or media rupture. (+info)
(6/2176) Lobar decrease in 99mTc-GSA accumulation in hilar cholangiocarcinoma.
Hilar cholangiocarcinoma can obstruct hepatic ducts and involve the portal veins. Both biliary stasis and decrease in portal venous flow are known to reduce 99mTc-diethylenetriamine pentaacetic acid-galactosyl human serum albumin (GSA) accumulation. The specific relationship between these pathological conditions due to hilar cholangiocarcinomas and 99mTc-GSA accumulation has never been clarified. METHODS: Sixteen patients with hilar cholangiocarcinomas who underwent 99mTc-GSA liver scintigraphy were reviewed. The relationship between significant decrease in 99mTc-GSA accumulation and lobar biliary stasis, or decrease in the portal venous flow, was evaluated. Average counts of region of interest placed in both right and left lobes were compared in the same transaxial SPECT section. Count ratios of right and left lobes were calculated. RESULTS: Significant lobar decrease in 99mTc-GSA accumulation was observed in 6 of the 16 patients. Ipsilateral portal venous stenosis or obstruction was seen in all these 6 patients, whereas ipsilateral portal venous stenosis or obstruction was seen in only 1 of the other 10 patients. Symmetric bile duct dilatation was seen in 13 patients, and asymmetric bile duct dilatation was seen in 3. Lobar decrease in 99mTc-GSA accumulation correlated well with decrease in ipsilateral portal venous flow (P < 0.0005). The count ratio was significantly reduced when unilateral portal venous flow decreased (P < 0.05). CONCLUSION: Using 99mTc-GSA liver scintigraphy, we can predict lobar decrease in ipsilateral portal venous flow and monitor hepatic functional lateralities in patients with hilar cholangiocarcinomas. (+info)
(7/2176) Origin of acinar cell regeneration after atrophy of the rat parotid induced by duct obstruction.
Acinar cell regeneration in the rat parotid gland after atrophy induced by a one week period of duct obstruction was examined using histology, immunohistochemistry and transmission electron microscopy (TEM). For immunohistochemistry, antibodies to 5-bromo-2'-deoxyuridine (BrdU), injected one hour before tissue collection, and cytokeratin were employed. When clips were removed from the duct, only ductal epithelial cells remained; all acinar cells had been deleted. Some duct cells were BrdU positive. After three days, newly-formed acini comprising immature acinar cells had appeared; many of the cells were BrdU positive and mitotic figures were readily identified. Thereafter progressive acinar cell maturation and proliferation occurred, parotid gland weight returning to control levels by 7 days. Peak BrdU labelling indices for duct and acinar cells were on days 0 and 4, respectively. By TEM, cytoplasmic organelles in epithelial cells of transitional duct-acinar structures seen at 2 days were poorly developed. Immature acinar cells seen on day 3 contained zymogen granules and had increased endoplasmic reticulum and mitochondria. By day 5, maturing acinar cells had abundant endoplasmic reticulum and zymogen granules, resembling acinar cells in control glands. These observations indicated origin of acinar cell precursors from duct cells during regeneration of the acinar cell-free atrophic gland. Subsequent expansion of the acinar cell population was dependent on maturation and proliferation of these newly-formed cells. (+info)
(8/2176) Long-term results and outcomes of crossover axilloaxillary bypass grafting: A 24-year experience.
OBJECTIVE: The outcome of crossover axilloaxillary bypass grafting in patients with stenosis or occlusion of the innominate or subclavian arteries was investigated. METHODS: The study was designed as a retrospective clinical study in a university hospital setting with 61 patients as the basis of the study. Fifty-eight patients (95.1%) had at least two risk factors or associated medical illnesses for atherosclerosis, and 35 patients (57.4%) had concomitant carotid artery stenosis that necessitated a staged procedure in 12 patients (19.7%). The patients underwent a total of 63 crossover axilloaxillary bypass grafting procedures. Demographics, risk factors and associated medical illnesses, preoperative symptoms and angiographic data, blood flow inversion in the vertebral artery, concomitant carotid artery disease, graft shape, caliber and material, and intraoperative and postoperative complications were studied to assess the specific influence in determining the outcome. RESULTS: One postoperative death (1.6%), four early graft thromboses (6.2%), and six minor complications (9. 8%) occurred. The overall mortality and morbidity rates were 1.6% and 16.1%, respectively. During the follow-up period (mean, 97.3 +/- 7.9 months), we observed five graft thromboses (8.3%). Primary and secondary patency rates at 5 and 10 years were 86.5% and 82.8% and 88.1% and 84.3%, respectively. Overall, two patients (3.3%) had recurrence of upper limb symptoms and none had recurrence of symptoms in the carotid or vertebrobasilar territory. The 5-year and 10-year symptom-free interval rates were 97.7% and 93.5%, respectively. Nine patients (15%) died of unrelated causes. The 5-year and 10-year survival rates were 93.2% and 67.3%, respectively. Multivariate analysis showed that no specific variables exerted an influence in the short-term and long-term results and the outcome. CONCLUSION: The optimal outcome of axilloaxillary bypass grafting supports its use as the most valuable surgical alternative to transthoracic anatomic reconstructions for innominate lesion, long stenosis of the subclavian artery, and short subclavian artery stenosis associated with ispilateral carotid artery lesions. (+info)