Influence of nutrient enrichment on temporal and spatial dynamics of dissolved oxygen within northern temperate estuaries.

In temperate estuaries of the southern Gulf of St. Lawrence, intermittent seasonal anoxia coupled with phytoplankton blooms is a regular occurrence in watersheds dominated by agricultural land use. To examine the spatial relationship between dissolved oxygen and phytoplankton throughout the estuary to assist in designing monitoring programs, oxygen depth profiles and chlorophyll measurements were taken bi-weekly from May to December in 18 estuaries. In five of those estuaries, dissolved oxygen data loggers were set to measure oxygen at hourly intervals and at multiple locations within the estuary the subsequent year. The primary hypothesis was that dissolved oxygen in the upper estuary (first 10% of estuary area) is predictive of dissolved oxygen mid-estuary (50% of estuary area). The second hypothesis was that hypoxia/superoxia in the estuary is influenced by temperature and tidal flushing. Oxygen depth profiles conducted in the first year of study provided preliminary support that dissolved oxygen in the upper estuary was related to dissolved oxygen throughout the estuary. However, dissolved oxygen from loggers deployed at 10% and 50% of estuary area did not show as strong a correlation as expected (less than half the variance explained). The strength of the correlation declined towards the end of summer. Spatial decoupling of oxygen within the estuary suggested influence of local conditions. Chlorophyll concentration seemed also to be dependent on local conditions as it appeared to be coupled with the presence of sustained anoxia in the upper estuary with blooms typically occurring within 7 to 14 days of anoxia. The practical implication for oxygen monitoring is that one location within the most severely impacted part of the estuary is not sufficient to fully evaluate the severity of eutrophication effects.

[Thirty-eight cases of dysplasia of the superior mesenteric artery]. / Trente-huit cas de lésions dysplasiques de l'artère mésentérique supérieure.

Dysplasia of the renal and cervical arteries are well known, but dysplasia of the superior mesenteric artery (SMA) is less frequent and has specific presentation. There have been few reports on the different types of presentations. We report a series of 38 cases and present the characteristic features together with a comparison with data in the literature. These non-atheromatous non-inflammatory lesions of the arterial wall occurred either in a context of fibromuscular disease which cause is unknown (30/38 patients) or in patients with genetic disease such as neurofibromatosis (3/38) or Ehlers-Danlos disease (5/38). The fibromuscular disease presented three aspects with specific characteristics. a) stenosing lesions found predominantly in women with a different morphology than in the other localization (usually associated): irregular diffuse stenosis discovered in patients with hypertension, or ischemic digestive symptoms (6/14 patients). b) Aneurysms, also found predominantly in women, but less frequently associated with other dysplasias. These aneurysms were generally sacciform. Unlike data in the literature, our series only included rupture in 1/8 cases. The aneurysm was discovered during the exploration of abdominal pain or hypertension. c) The third type of fibromuscular disease concerned dissections which were observed in the male population, (except one case of segmental dysplasia), and presented with signs of digestive ischemia in the other seven patients, four in an emergency context requiring immediate treatment. Two genetic diseases were observed. a) Neurofibromatosis led to dysplasia analogous to fibromuscular disease, but with abnormal nerve formations in the wall. For the three cases observed, one involved only the visceral arteries and the two others thoraco-abdominal coarctation. b) We had five patients with Ehlers-Danlos syndrome, with dysplasia of the superior mesenteric artery. For three there was a fusiform dilatation and in one small aneurysms along the arterial trunk, which only required surveillance. There was only one aneurysm which required treatment by resection and venous graft. In these young patients, revascularization was generally achieved with autologous material and the prognosis was favorable. Embolization was successful in treating the sacciform aneurysm in one patient. In conclusion, dysplasia of the superior mesenteric artery has a specific presentation which must be recognized to enable diagnosis of this not uncommon condition in young subjects (even children) who often present with an acute abdomen requiring urgent treatment.

Long-term follow-up of positive cultures in 500 abdominal aortic aneurysms.

Routine aneurysm culture is frequently performed as it is thought that a positive culture could be a risk factor for secondary graft infection. Five hundred aneurysms, in a series of 796 patients, had microbiologic examination of the thrombus and/or aneurysm wall. Cultures were positive in 185 cases (37%), mostly due to normal skin flora microorganisms (80%), whereas 16 patients (3.2%) had infectious aortitis. Gram-stained smears were positive in nine of these 16 patients compared with two of the other 169. Of the 185 patients with positive culture, after a mean length of follow-up of 35 months, only one had a graft infection that occurred 6 years later and was not due to the same microorganism. Graft sepsis was diagnosed in six of the 296 patients who did not have a positive culture, and was related to clinically obvious locoregional or systemic foci. In this series, positive cultures from aneurysm without rupture or signs of infection were not a risk factor for secondary graft sepsis. Therefore, in cases of asymptomatic unruptured aneurysm, routine culturing is not necessary as a positive result has no pathogenic significance or therapeutic implication.

Surface healing and histologic maturation of patent polytetrafluoroethylene grafts implanted in patients for up to 60 months.

Histologic, transmission, and scanning electron microscopic observations were made of 26 biopsy specimens from patent polytetrafluoroethylene grafts that had been implanted as arterial bypasses for up to 60 months. The results showed the rarity of host connective tissue ingrowth, the absence of neovascularization, and the limited neointimal proliferation. The defect of staining for factor VIII-related antigen by immunohistochemistry confirmed the absence of true endothelial cells at a distance from the anastomoses. Under electron microscopy the thin neointimal layer consisted mainly of fibrin, platelets, blood cells, and cellular debris. Even in prostheses implanted for the longest periods, mature collagen and elastin were not found. Tubular microfibrils (9- to 12-nm thick) could be observed. The source of such microfibrils, probably glycoproteins, remains under investigation.

Surgical management of vertebral-basilar insufficiency.

The authors report 251 cases of lesions of the major branches of the aortic arch and the vertebral artery in 172 patients. A detailed account is given of the observed lesions (34 lesions of the innominate artery, 93 of the subclavian artery and 119 of the vertebral arteries), the techniques used and the indications for surgery. The use of the cervical approach seems to be justified in order to adapt the extent of cure to the patient's condition and accounts for the low mortality rate of 1.5%.

Infection complicating aortoiliac surgery.

25 cases of sepsis complicating aorto-iliac surgery have been encountered in the period 1970 to 1976 (8 cases occured in our own unit and 17 were received from elsewhere). There were 10 instances of infection following thromboendarterectomy and all 10 were treated successfully. Among the 19 patients with infected prostheses (14 primary, 5 secondary) there were 5 deaths(1 myocardial infarct, 2 septicaemia, 2 aortic haemorrhages) and 3 amputations. The treatment of choice for infected thromboendarterectomy cases is iliac exclusion coupled with either an obturator by-pass or a femoro-femoral vein graft using the perineal route. An infected prosthesis should be removed and circulation restored by means of an axillofemoral-bypass, or a femoro-femoral vein graft or a combination of the two. Occasionally an infected aorto-femoral prosthesis can be treated by removal of one limb only followed by obturator or axillo-femoral by-pass. The prophylactic value of omentopexy in aortoiliac surgery is emphasised.

Streptokinase after late failure of reconstructive surgery for peripheral arteriosclerosis.

After the failure of reconstructive surgery for arterial occlusions of the lower limbs, 25 patients with severe ischemia were treated with streptokinase (SK) to avoid amputation of the limbs and sometimes death, in the absence of any other possible treatment. In 16 subjects, thrombolysis, assessed by the Doppler ultrasound technique, occurred rapidly; in 12 cases, SK combined with surgery or with symptomatic medical treatment gave good results saving limbs and improving the quality of life. Three of the 16 patients died from a cerebral vascular accident which occurred before the 10th hour. Whatever the type and the number of surgical operations performed before the use of SK, the indications and the results of the treatment are governed by the condition of the vascular tree below the arterial lesions. SK seems to be justified in endarterectomy or venous grafts with severe ischemia less than two months old. For dacron by-passes, the possibility of prosthesis dissection makes SK debatable in spite of frequent lysis. In axillofemoral by-passes, the risk of embolism of the upper limbs makes the use of SK inadvisable.

Local urokinase in arterial thromboembolism.

Selective intra-arterial urokinase (UK) is effective in treating recent arterial thromboembolism. However, usually only partials lysis is achieved and this treatment seems less effective than intravenous streptokinase. At a dose of 37,500 UCTA/hour it does not produce systemic fibrinolysis. This protocol substantially reduces the risk of systemic bleeding and embolism and extends its applicability to operative patients. The combination of surgery and UK seems particularly promising in patients with atherosclerotic arterial thrombosis.

[Vascular complications after the treatment of carcinoma of the cervix (author's transl)]. / Complications vasculaires tronculaires après traitement du cancer du col utérin.

Vascular complications after this treatment are rare. Artery stenosis or occlusions, more often iliac, are well recognized complications of postoperative radiotherapy. These segmental lesions, sometimes, are pathological lesions similar to arteriosclerotic changes. These lesions may be corrected later on after the treatment of carcinoma of the cervix. The venous complications often present later and tall within the context of post thrombotic syndrome. Conservative treatment is indicated alone. A well recognized complication, lymphedema is usually mild; a superimposed iliofemoral thrombophlebitis often may be suspected.

[Surgical results in stage 2 arterial diseases]. / Résultats chirurgicaux dans les artériopathies de stade II.

The results of surgical treatment of peripheral artery disease at the stage of intermittent claudication may now be assessed with a 40 year follow-up. In selected cases the 10 year patency rate of aortoiliac revascularisation is 90% and the 5 year patency rate of femoropopliteal revascularisation is 85%. When the indications are widened to include less favourable lesions giving rise to severe claudication, the patency rate falls to 60% at 5 years. These results should improve with better preoperative assessment by Doppler ultrasonography the use of new material and methods (endovascular) and stricter control of the revascularisation procedure by angioscopy in patients with severe effort ischaemia which is the principal surgical indication; the association of endovascular revascularisation procedures has increased the therapeutic indications and improved the functional result.

[True and false popliteal artery entrapment in sportsmen]. / Vraie et fausse artére poplitée piégée chez les sportifs.

Popliteal artery entrapment and its various anatomical type I, II, III and IV has been perfectly described in previous studies. The only test that diagnoses true entrapment due to an anatomical abnormality in the course of the popliteal artery, where it is tied by an embryonic anomaly, is passive dorsiflexion of the foot on the extended leg the deviation then observed at ultrasonography and angiography and the disappearance of downstream signal at doppler examination are pathognomonic. Ultrasonography, computerized tomography (CT) and, more recently, nuclear magnetic resonance (NMR) provide detailed information on the abnormality: separation of the artery from the vein by a muscular bridge is the hallmark of true popliteal entrapment. On the other hand, there is a functional pathology due to dynamic compression of the popliteal artery by the medial gastrocnemius muscle, which raises difficult diagnostic and therapeutic problems, especially in high-level sportsmen for whom the leg muscle activity is very important. In these subjects with a developed muscular mass the medial gastrocnemius muscle crushes the popliteal artery against the femoral condyle without deviation of the artery, particularly in active dorsiflexion and activity hyperextension of the foot on the extended leg. In such case, the popliteal artery and vein remain close to each other, as demonstrated by ultrasounds, CT and NMR. True popliteal artery entrapment can be cured by surgery with subsequent resumption of sporting activities, but whether false entrapment must be operated is difficult to decide. Surgery has been performed with success in some cases of highly disabling false entrapment due to compression of the artery by the medical gastrocnemius muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

[Extratemporal Horton's disease: diagnosis using subclavian biopsy. 4 cases]. / Maladie de Horton à localisation extratemporale: diagnostic par la biopsie sous-clavière. 4 observations.

A histological diagnosis of Horton's disease was made in 4 patients with lesions of the axillary-subclavian arteries by biopsy of these vessels. Unilateral biopsy of the temporal artery, performed initially in 2 of these patients, during surgery in one and immediately after surgery in another, had been negative in 3 cases and insufficient for a diagnosis in 1 case. For temporal biopsy to be valuable, the arterial fragment resected must be long enough and serial histological sections must be performed to avoid false-negative results. It is only when these conditions are fulfilled that negative results may be considered. Horton's disease of the axillary-subclavian arteries is relatively frequent, and histological studies of these vessels have already been used to assert the diagnosis in case of negative or non-performed temporal biopsy, whether or not the arteriographic findings were suggestive of the disease. The indications for subclavian biopsy remain to be determined. It can be carried out for diagnostic purposes in case of clinically atypical suspected Horton's disease revealed by axillary-subclavian lesions and negative temporal biopsy, particularly when revascularization proves necessary.

[Congestive cardiac failure secondary to hepatico-portal arteriovenous fistula. Apropos of a case and review of the literature]. / Insuffisance cardiaque globale secondaire à une fistule artério-veineuse hépatico-portale. A propos d'une observation et revue de la littérature.

A 66 year old man with mild hypertension developed congestive cardiac failure of rapid onset associated with a continuous epigastric murmur suggesting an arteriovenous fistula. Doppler ultrasonography, computed tomography, magnetic resonance imaging and abdominal arteriography showed the fistula to arise from a large thrombosed aneurysm of the hepatic artery which had ruptured into the portal vein. Echocardiography and radionuclide angiography showed normal left ventricular systolic function. The patient underwent aneurysmorrhaphy and suture of the portal vein without any complications and the murmur and signs of cardiac failure disappeared. Histological examination showed the arterial lesion to be due to atherosclerosis. The authors underline the rarity of aneurysms of the hepatic artery and, above all, of their rupture into the portal system as there have only been 7 previously reported cases. Fistulae of the portal system are usually well tolerated, the commonest complication being portal hypertension. Cardiac failure is an exceptionally rare occurrence: it may be observed when the fistula develops suddenly and has a high flow rate, and in patients with abnormal myocardial function.

[Acute upper limb ischemia in a young adult without cardiac disease. Value of transesophageal echocardiography]. / Ischémie aiguë des membres supérieurs chez une adulte jeune sans cardiopathie. Intérêt de l'échographie transoesophagienne.

The authors report the case of a 34-year old woman with no previous cardiovascular disease who was admitted to hospital for acute ischaemia of the right arm due to embolism, preceded by two episodes of pain and tingling of the left arm related to subacute ischaemia. After right embolectomy, with no possibility of controlateral disobliteration an effective anticoagulation, no cardiac source of embolism could be found; However, transoesophageal echography showed a large mobile thrombus in the aortic arch implanted just before the origin of the left subclavian artery. The only explanation for embolism to the right arm was a retro-oesophageal subclavian artery which was confirmed by scanner. Doppler and arteriography. These investigations, however, did not allow visualisation of the aortic thrombus. In view of the risk of recurrent embolism, a thrombectomy was performed without cardiopulmonary bypass, associated with correction of the vascular abnormality with no complications. This case shows that oesophageal echography is a useful investigation in the work up of acute arterial obstruction in young patients with no cardiac disease.

[Internal carotid artery surgery using a venous graft]. / Chirurgie de l'artère carotide interne par greffe veineuse.

Thromboendarterectomy is the most popular technique of carotid restoration for atheromatous lesions. In some cases, endarterectomy may be difficult or hazardous to perform, when atherosclerotic lesions involve the proximal common carotid artery and/or the distal internal carotid artery, when they are radiation induced, and when they are associated with fibromuscular dysplasia, loops or kinking. In other cases, result of endarterectomy may be unsatisfactory, because of a traumatic lesion of the arterial wall during endarterectomy, or a stenosis of the arteriotomy closure. Postoperative and late restenosis and occlusion rate range between 10 and 50% after primary closure of the carotid arteriotomy. Some of these complications may be reduced by alternative techniques such as eversion endarterectomy or patch angioplasty closure. Reversed saphenous bypass may also be performed. In our experience, only suitable autologous greater saphenous vein shall be harvested, including adequate length, absence of valves, diameter greater than 4 mm, and excellent wall texture. Distal anastomosis on the internal carotid artery shall be performed end-to-side with ligation of the internal carotid stump, and not end-to-end. Thus, in that location, venous grafts have excellent long-term patency with less than 5% late restenosis or occlusion rate. Thus, venous graft bypass may be an alternative technique to carotid endarterectomy, especially in young patients and women, who are more often exposed to late complications.

[Extrinsic compression of the popliteal artery (author's transl)]. / Compressions extrinsèques de l'artère poplitée.

Popliteal artery compression may be due to trapping of the artery, a tumor, or a subadventricial cyst. Diagnosis is suggested by the discovery of ischemia in a subject who is often young, this being an unusual finding. It is confirmed by dynamic doppler tests, ultrasonography, and vascular opacification. Eight cases of trapped popliteal, three of osteochondroma, and seven cases due to cysts were observed. Surgical treatment is regularly effective and can prevent complications of embolism and acute thrombosis.

[Treatment of aneurysmal disease]. / Traitement de la maladie anévrismale.

The technique used for an isolated lesion, involving an emptying-graft procedure, is discussed initially, together with particular features related to proximal and distal lesions. The treatment of multiple aneurysms is then evoked, including the attitudes necessary when confronted with either atheromatous disease or aneurysmal polydystrophy.

[The role of lumbar sympathectomy in the treatment of diabetic arterial disease (author's transl)]. / La place de la sympathectomie lombaire dans le traitement des artérites diabétiques.

220 lumbar sympathectomies were performed in 206 patients. Postoperative mortality morbidity were essentially related to the cardiovascular past history of the patients and indications for surgery must be very carefully weighed, in particular after the age of 70 years. Sympathectomy markedly increases the chances of healing of patients with ischaemic trophic disturbances. It shortens the time required for healing, whatever the type of gangrene.

[Takayasu's disease involving the vessels arising from the arch of the aorta and those of the upper limbs (author's transl)]. / Maladie de Takayasu. Troncs supra-aortiques et membres supérieurs.

Lesions localized to the vessels arising from the aortic arch and those in the upper limbs were observed in 72 out of 84 patients with Takayasu's disease. In 54% of these 72 cases, other regions were affected, while only the vessels arising from the arch of the aorta were the site of lesions in the other 46% (isolated axillo-post-vertebral subclavian lesions were present in 14% of cases). Semiological features, long-term complications, and prognosis are discussed. 53 revascularizations were performed in 47 patients without mortality. Surgery is definitely indicated when severe stenosis of the brachiocephalic vessels or the main carotid arteries or their division exists. Revascularization of a subclavian artery stenosis should be limited to cases with ischemia of the upper limb on effort or when a histological diagnosis is required. Controversy exists as to the need for this operation in ectatic forms.

[Diabetic arterial disease. Surgical indications of the basis of a series of 416 cases (author's transl)]. / Les artériopathies diabétiques. Indications chirurgicales à propos d'une série de 416 cas.

416 cases of diabetic arterial disease were treated over a period of 5 years, the majority of patients (71%) having trophic problems from the outset. -- Clinically, distinction must be drawn between patients suffering from "ischemic" disturbances, where healing is obtained after an appropriate surgical procedure (reconstructive surgery, if not lumbar sympathectomy) and so-called "diabetic" gangrene, where cure is obtained only by isolated excision. -- Few of the patients had lesions making reconstructive surgery possible, and the latter was thus only rarely indicated (13% of cases). -- So-called "major" amputations through leg or thigh were necessary in 16% of cases. Distal excision, if necessary atypical, thus in 84% of cases led to healing with preservation of weight-bearing.