Biomedical subjects
Publications and source records attributed to R Limet.
Through the presentation of a classical case of intrapulmonary pulmonary sequestration, the nosology of congenital lung malformations is reviewed. The histology, imaging, and surgical treatment of this congenital anomaly are briefly discussed.
We report the case of a spontaneous posterior tracheal wall rupture following a cough. A 67-year-old woman with a history of longstanding treatment with corticosteroids (8 years) for Giant Cell Arteritis had general anesthesia for cataract removal. Surgery and anesthesia were uneventful. In the recovery room, the patient coughed and soon after developed subcutaneous emphysema of the neck. Chest radiography confirmed the clinical diagnosis of marked subcutaneous emphysema and showed huge pneumomediastinum and minor right pneumothorax. A thoracic CT scan revealed a large laceration of the posterior tracheal wall (a 4 cm longitudinal tear), extending from the middle of the trachea to the level of the carina. Surgical repair consisted in closure of the dilaceration using an autologous pericardial patch. It seems reasonable to suspect the facilitating role of connective tissue fragility due to chronic corticosteroid administration in the development of this tracheal rupture following cough. Tracheal rupture is a potentially lethal injury, which can be repaired successfully if the diagnosis is made early. Risk factors, diagnosis and principles of treatment of this lesion are discussed.
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Infrarenal mycotic aneurysms are rare. The classic symptomatic triad is abdominal pain, fever and a pulsatile, rapidly growing abdominal mass. We present two cases of mycotic abdominal aneurysm, recently managed. The principles of diagnosis and treatment of mycotic aneurysm are reviewed and discussed.
Abdominal aortic rupture is sometimes paroxystic. More often, the rupture process takes hours, even days. Surgical efficiency is dependant on an early diagnosis.
Up to now, the prognosis of peritoneal carcinomatosis from GI tract cancers remains very poor. Intraperitoneal hyperthermic chemotherapy has been proposed in the prevention or treatment of peritoneal carcinomatosis. The rationale for this locoregional approach comes from a better knowledge of the physiopathology of the disease. Intraperitoneal chemotherapy achieves high local drug concentration with limited systemic toxicity. It should be performed during or immediately after surgery to be effective towards microscopic residual tumor cells. A synergistic cytotoxic effect has been demonstrated when heat is combined with antineoplastic drugs. Intraperitoneal hyperthermic chemotherapy might not be regarded as the panacée but as a promising step in the management of peritoneal carcinomatosis. Some randomized studies of gastric cancer with macroscopic serosal invasion have suggested the efficacy of hyperthermic intraperitoneal chemotherapy for the prevention of peritoneal carcinomatosis. In patients with peritoneal carcinomatosis, some studies suggest, in selected cases, the positive effect of hyperthermic intraperitoneal chemotherapy on survival, when combined with cytoreductive surgery.
The knowledge of the anatomy of the atria and interatrial septum permits different routes to approach the left atrioventricular valve. The Waterston's or Sondegaard's groove approach is the most frequently used, but other approaches such as Dubost'transseptal technique, vertical transseptal approach (Berreklouw-Guiraudon), biatrial inferior transseptal approach (Couëtil) or Saksena's approach may be relevant in special situations. It is the purpose of this article to review the anatomic and technical basis of these different approaches and their respective merits.
OBJECTIVE: To evaluate the long-term outcome of greater saphenous vein (GSV) infrapopliteal revascularisation in a single centre over a 10 year period. MATERIAL AND METHODS: Fourty-one variables relating to a consecutive series of 90 crural artery GSV(76% in situ) bypasses in 81 patients (1990-2000) were analysed. The mean age of the 47 men and 34 women was 70 years. Limb-threatening ischaemia was present in 96% of cases, claudication in four patients. In 18 patients, surgery was 'redo'. RESULTS: The perioperative mortality was 3% (n=3). Patient survival was 54% at 4 years. Independent risk factors affecting survival were chronic renal insufficiency (p=0.04), hypertension (p=0.02), and ischaemic heart disease (p=0.01). Four bypasses thrombosed within 30 days. Three of them could be successfully reopened. Mean follow-up was 39 months. The primary patency rate at 4 years was 80%. Chronic renal insufficiency revealed to be the single independent risk factor for graft thrombosis (p=0.03, RR=12.4). The 4-year limb salvage rate was 88%. No independent risk factor affecting the limb salvage could be identified. CONCLUSION: Crural artery revascularisation is a valuable option for the management of limb threatening infrapopliteal arterial occlusive disease.
OBJECTIVES: Proximity of ureters with iliac arteries makes them prone to damage by aorto-iliac pathology or surgery. The aim of this retrospective study is to analyse the incidence, the predisposing factors, and the optimal treatment of ureteral stenosis (US) or leakages (UL). DESIGN: Retrospective study. MATERIAL: Fifty-one ureteral lesions in 41 patients referred to the urologist in a fourteen years period in the same institution. METHODS: Lesions are classified in three groups: A, preoperative; B, less than 3 months postoperatively; and C, more than 3 months postoperatively. Group A comprises 10 abdominal aortic aneurysm (AAA) patients; eight of the AAA are of the inflammatory type. Group B comprises 16 patients, 11 US and 9 UL. Group C comprises 15 patients and 15 US. RESULTS: Endoureteral treatment was successful in most of the group B patients. Some of them, however, had to be submitted to secondary open surgery, so that the global success rate is 70% in group B. In group C, the response is poor following endourological treatment alone (12.5% success) and open surgery is more often needed (3 ureterolyses and 1 nephrectomy). Global success rate is 40%. CONCLUSION: Early diagnosis is associated to better results with less invasive procedure; late diagnosis is accompanied by a lower success rate of endourological treatment and requires more often primary open surgery.
OBJECTIVES: in patients with vascular prosthesis infection, to compare surgical outcome and long-term results of cryopreserved allograft implantations to conventional surgery. DESIGN: retrospective study. MATERIAL AND METHODS: two asynchronous series of 44 [series I: 1980-1994; 8 patients with aortoenteric fistula (AEF)] and 22 (series II: 1994-1997; 4 patients with AEF) patients were treated for prosthesis infection. All patients had prosthesis excision. In series I, there were 4 in situ reparations, 26 extra-anatomic bypass, 13 excision only, and one death at laparotomy. In series II, in situ cryopreserved allografts were implanted in all patients. RESULTS: operative mortality was 16% in series I and 13.6% in series II. For AEF patients, mortality was 37% in series I and 50% in series II. Among hospital survivors, infection-related late mortality was 13.5% in series I and 5% in series II. For AEF patients, late mortality was 20% in series I and 50% in series II. Incidence of reoperations was 54% in series I and 10.5% in series II (p<0.01). Hospital stay was 47.2+/-26.4 days in series I and 16.6+/-11.5 days in series II (p<0.001). CONCLUSIONS: compared to conventional treatment, incidence of reoperations and length of hospital stay are significantly decreased after cryopreserved allograft implantation. However, closure of aortic stump and extra-anatomic bypass gives better results for patients with AEF.
We studied the effects on pulmonary hemodynamics of U-46619, a thromboxane A2 (TXA2) agonist, before and after administration of a novel TXA2 receptor antagonist and synthase inhibitor (BM-573). Six anesthetized pigs (Ago group) received 6 consecutive injections of U-46619 at 30-min interval and were compared with six anesthetized pigs (Anta group) which received an increasing dosage regimen of BM-573 10 min before each U-46619 injection. Consecutive changes in pulmonary hemodynamics, including characteristic resistance, vascular compliance, and peripheral vascular resistance, were continuously assessed during the experimental protocol using a four-element Windkessel model. At 2 mg/kg, BM-573 completely blocked pulmonary hypertensive effects of U-46619 but pulmonary vascular compliance still decreased. This residual effect can probably be explained by a persistent increase in the tonus of the pulmonary vascular wall smooth muscles sufficient to decrease vascular compliance but not vessel lumen diameter. Such molecule could be a promising therapeutic approach in TXA2 mediated pulmonary hypertension as it is the case in pulmonary embolism, hyperacute lung rejection and endotoxinic shock.
After reviewing the historical background, the morphology and physiopathology of left ventricular aneurysms, the authors review the physiology, the technical aspects, and the current surgical indications of aneurysmectomy, with a particular emphasis on the concept of endoventriculoplasty of Jatène & Dor.
AIM: Myocardial revascularisation being frequently performed during acute myocardial ischemia, in a hostile hemodynamic environment, we evaluated left ventriculo-arterial (VA) coupling, left ventricular (LV) mechanical efficiency, and the mechanical properties of the systemic vasculature during acute myocardial ischemia. METHODS: In 6 pigs, vascular properties [characteristic impedance (R(1)), peripheral resistance (R(2)), compliance (C), inductance (L), arterial elastance (E(a))] were estimated with a windkessel model. LV function was assessed by the slope (E(es)) of end-systolic pressure-volume relationship (ESPVR), and stroke work (SW) - end-diastolic volume (EDV) relation. Pressure-volume area (PVA) was referred to as myocardial oxygen consumption. VA coupling was defined as E(es)/E(a), and mechanical efficiency as SW/PVA. After baseline recordings, the left anterior descending coronary artery was ligated and hemodynamic measures obtained every 30 minutes for 3 hours. Data are expressed as mean (SEM). RESULTS: Coronary occlusion induced an ESPVR rightward shift, and decreased E(es) from 3.67 (0.33) to 1.92 (0.20) mmHg/ml and the slope of the SW - EDV relationship from 72.3 (3.4) to 40.4 (4.5) mmHg (p<0.001), while E(a) increased from 3.33 (0.56) to 4.65 (0.29) mmHg/ml (p<0.005). This was responsible for a dramatic alteration of VA coupling from 1.22 (0.11) to 0.44 (0.07), (p<0.001). While R2 increased from 1.72 (0.30) to 2.38 (0.16) mmHg x s x ml(-1) (p<0.05) and C decreased from 0.78 (0.16) to 0.46 (0.08) ml/mmHg (p<0.05), R(1) and L were unchanged. Coronary occlusion decreased SW from 4056 (223) to 2580 (122) mmHg.ml (p<0.001), while PVA and SW/PVA decreased from 5575 (514) to 4813 (317) mmHg x ml (NS), and from 0.76 (0.04) to 0.57 (0.03) (p<0.001), respectively. CONCLUSION: Acute myocardial ischemia severely altered left ventriculo-arterial coupling and LV mechanical efficiency. Impaired left VA coupling was due to a combination of augmented arterial elastance, secondary to early vasoconstriction later associated with decreased arterial compliance, and decreased LV contractility.
Coronary artery bypass surgery has shown its superiority on other therapeutic options in specific but frequent indications such as left main lesions, multivessel disease with alteration of ventricular function, proximal lesions of the LAD, and multivessel diseases in diabetic patients. After reviewing the epidemiology of coronary artherosclerosis, we emphasize the efficacy of the surgical treatment compared to medical or interventional therapy for preventing ischemic events. The results derived from randomized studies may be even further improved by the implementation of beating heart surgery and the systematic use of multiple arterial conduits.
Early and late results of North American Trial (NASCET) demonstrate the efficacy of surgery to prevent major ipsilateral stroke in symptomatic patients; the benefit is proportional to the degree of stenosis. In asymptomatic patients, the benefit is real, but quantitavivement less pronounced.
Only few dissecting aneurysms type A survive without surgery. Opposingly, the dissecting aneurysms type B are successfully managed by the medical treatment "anti-impulsion". A personal series is reported, that evidence important cardiovascular mortality in the follow-up in chronic dissecting aneurysms type B; one part of this late mortality is linked to rupture of the thoracic descending aorta. Thus, the prevention of this late mortality depends on a strict follow-up of the characters and dimensions of descending aortic thoracic aorta.
Open repair of AAA effectively prevents the death by rupture. Surgery is indicated if operative mortality is low (< 2%) and AAA at high risk of rupture, i.e. large transverse diameter. Higher risk subgroups can be identified. The role of open repair is justified in these conditions.
Peripheral vascular surgery (carotid, infrainguinal or aortoiliacal) is characterised by an increased cardiac risk with an infarction rate of 1 to 4%. Sixty percent of the vascular patients present a concomitant coronary artery disease, often infraclinically. Preoperative cardiac risk stratification aims at reducing cardiac related morbidity and mortality. A clinical risk profile (patient's past history) and non-invasive cardiac tests allow subdividing the vascular patients into three categories: high risk, intermediate risk, and low risk. High-risk patients (unstable angina, recent infarction, overt congestive heart failure and critical aortic valve stenosis) require immediate intensive management of their underlying cardiac disease. This means delay or annulation of the planned vascular operation. For intermediate risk patients, a clinical cardiac risk index based on patient's past history (stable angina, previous infarction or episode of congestive heart failure, age of 70 years or more and diabetes) offers a rough orientation. These clinical markers lack specificity, since they are found in almost all vascular patients. The adjunction of a non-invasive cardiac testing allows to optimise the cardiac risk evaluation. Stress echocardiography with dobutamine has become a very popular test, with a negative predicting value exceeding 90%, but with a lack of specificity (many vascular patients have an uneventful postoperative outcome, despite a positive dobutamine test). These inconsistent results of cardiac risk evaluation render their routine use questionable. Nowadays, the management of patients requiring vascular surgery is based on the concept that every vascular patient should be considered as suffering from coronary artery disease. A certain degree of myocardial protection should be offered to every vascular surgery candidate. A preoperative treatment with betablockers provides myocardial protection against the operative stress and lowers myocardial oxygen requirement. There are arguments to continue or start aspirin treatment in the preoperative period, in order to lower the risk of sudden coronary thrombosis.