Management of thromboembolism-in-transit with pulmonary embolism.

We present a rare complication of deep venous thrombosis with pulmonary embolism that threatened the patient with systemic embolization. A 36-year-old female was referred to the hospital after five days of progressive shortness of breath and chest pain. Preceding onset of symptoms, she had undergone surgery leading to reduced physical activity and had just returned from vacation by a long flight. Investigations with transthoracic and transesophageal echocardiography revealed a thromboembolism-in-transit across a patent foramen ovale. Thoracic CT showed submassive bilateral pulmonary embolism. Hemodynamic parameters were stable. The patient was treated surgically with extraction of the thrombus, closure of the foramen ovale and removal of the bilateral pulmonary emboli. She was discharged after an uneventful hospital stay. LEARNING POINTS: Thromboembolism-in-transit across a patent foramen ovale usually occurs in the presence of deep venous thrombosis with pulmonary embolism. The abrupt rise in pulmonary arterial pressure may contribute to the migration of the thrombus across the atrial septum to the systemic circulation.If any abnormal structures are seen in the left atrium by TTE in a patient with pulmonary embolism, a TEE should be performed to rule out an embolus entrapped in a patent foramen ovale.When acute pulmonary hypertension cannot be assessed by conventional methods, additional parameters such as shortened right ventricular outflow tract acceleration time and a mid-systolic notching of the pulse wave Doppler profile in the right ventricular outflow tract may be useful.Mortality is highest during the initial 24 h after onset of chest symptoms; thus, optimal treatment must commence urgently.The choice of treatment in each individual patient must be made after a thorough discussion in a multidisciplinary heart team.

Randomised comparison of percutaneous left ventricular assist device with open-chest cardiac massage and with surgical assist device during ischaemic cardiac arrest.

AIMS: A percutaneous left ventricular assist device can maintain blood flow to vital organs during ventricular fibrillation and may improve outcomes in ischaemic cardiac arrest. We compared haemodynamic and clinical effects of a percutaneous left ventricular assist device with a larger device deployed via endovascular prosthesis and with open-chest cardiac massage during ischaemic cardiac arrest. METHODS: Eighteen swine were randomised into three groups. After thoracotomy, coronary ischaemia and ventricular fibrillation was induced. Cardiac output was measured with transit-time flowmetry. Tissue perfusion was measured with microspheres. Defibrillation was performed after 20 min. RESULTS: Cardiac output with cardiac massage was 1129 mL min⁻¹ vs. 1169 mL min⁻¹ with the percutaneous- and 570 mL min⁻¹ with the surgical device (P < 0.05 surgical vs. others). End-tidal CO2 was 3.3 kPa with cardiac massage vs. 3.2 kPa with the percutaneous- and 2.3 kPa with the surgical device (P < 0.05 surgical vs. others). Subepicardial perfusion was 0.33 mL min⁻¹ g⁻¹ with cardiac massage vs. 0.62 mL min⁻¹ g⁻¹ with both devices (P < 0.05 devices vs. massage), cerebral perfusion was comparable between groups (all reported values after 3 min cardiac arrest, all P<0.05 vs. baseline, all P = NS for 3 min vs. 15 min). Return of spontaneous circulation was achieved in 5/6 subjects with cardiac massage vs. 6/6 with the percutaneous- and 4/6 with the surgical device (P = NS). CONCLUSION: The percutaneous device improved myocardial perfusion, maintained cerebral perfusion and systemic circulation with similar rates of successful defibrillation vs. cardiac massage. Increased delivery was not obtained with the surgical device during cardiac arrest.

Finite element analysis of the mitral apparatus: annulus shape effect and chordal force distribution.

This study presents a three-dimensional finite element model of the mitral apparatus using a hyperelastic transversely isotropic material model for the leaflets. The objectives of this study are to illustrate the effects of the annulus shape on the chordal force distribution and on the mitral valve response during systole, to investigate the role of the anterior secondary (strut) chordae and to study the influence of thickness of the leaflets on the leaflets stresses. Hence, analyses are conducted with a moving and fixed saddle shaped annulus and with and without anterior secondary chordae. We found that the tension in the secondary chordae represents 31% of the load carried by the papillary muscles. When removing the anterior secondary chordae, the tension in the primary anterior chordae is almost doubled, the displacement of the anterior leaflet toward the left atrium is also increased. The moving annulus configuration with an increasing annulus saddle height does not give significant changes in the chordal force distribution and in the leaflet stress compared to the fixed annulus. The results also show that the maximum principle stresses in the anterior leaflet are carried by the collagen fibers. The stresses calculated in the leaflets are very sensitive to the thickness employed.

Frequent sampling allows detection of short and rapid surges of exhaled ethane during cardiac surgery.

During cardiopulmonary bypass (CPB), hypoperfusion and reperfusion may cause oxidative stress and lipid peroxidation that generates ethane. The aim of this pilot study was to assess the feasibility of frequent sampling of exhaled ethane during cardiac surgery. After approval of the Research Ethics Committee, 10 patients undergoing combined aortic valve and coronary artery bypass surgery were enrolled. Breath samples were drawn in the perioperative period and analyzed by a rapid, sensitive and validated gas-chromatographic method. Increased exhaled ethane was regularly seen following sternotomy, after the start of CPB and after aortic clamp removal, whereas no change was seen after termination of bypass. In one patient, the maximum increase in exhaled ethane was 30-fold. Peak durations lasted only 2-4 min. This study demonstrates that frequent sampling of breath ethane is feasible in a clinical setting, allowing detection of rapid ethane surges of short duration.

Detection of myocardial viability by dobutamine stress echocardiography: incremental value of diastolic wall thickness measurement.

OBJECTIVE: To assess the diagnostic accuracy of baseline diastolic wall thickness (DWT) alone and as an adjunct to dobutamine stress echocardiography (DSE) for prediction of myocardial viability in patients with ischaemic left ventricular (LV) dysfunction, with the recovery of resting function after revascularisation as the yardstick. PATIENTS: 24 patients with ischaemic LV dysfunction (ejection fraction < 40%) scheduled for surgical revascularisation. SETTING: Regional cardiothoracic centre. METHODS: All patients underwent DSE before and resting echocardiography six months after revascularisation. DWT was measured in each of the 16 LV segments. A receiver operating characteristic (ROC) and a multi-ROC curve were generated to assess the ability of DWT alone and in combination with DSE to predict myocardial viability. RESULTS: DWT > 0.6 cm provided a sensitivity of 80%, a specificity of 51%, and a negative predictive value of 80% for the prediction of viability in akinetic segments. DSE had an excellent specificity (92%) but a modest sensitivity (60%) in akinetic segments. A combination of improvement at DSE or DWT > 0.8 cm improved sensitivity (90% v 60%, p < 0.001) and negative predictive value (92% v 78%, p = 0.03) in akinetic segments compared with DSE alone. This was achieved with some loss in specificity (75% v 92%, p = 0.01) and positive predictive value (71% v 82%, p = 0.79). CONCLUSIONS: DWT measurement may improve the sensitivity of DSE for the detection of myocardial viability. Akinetic segments with DWT > 0.8 cm have a good chance of recovery despite the absence of contractile reserve during DSE. Further testing may be required before excluding myocardial viability in these cases.

Changes in cerebral oxygenation during cold (28 degrees C) and warm (34 degrees C) cardiopulmonary bypass using different blood gas strategies (alpha-stat and pH-stat) in patients undergoing coronary artery bypass graft surgery.

BACKGROUND: Impaired cerebral oxygenation, which is reflected by measuring jugular bulb oxygenation, is thought to play an important role in the development of neurological injury after cardiac operations with cardiopulmonary bypass (CPB). The effects of cardiopulmonary temperature and blood gas strategy on cerebral oxygenation are not fully appreciated. METHODS: Sixty patients were randomly allocated into four equal groups (cold alpha-stat, cold pH-stat, warm alpha-stat and warm pH-stat) to compare the effect of these perfusion strategies on cerebral oxygenation monitored by jugular bulb oximetry [jugular bulb oxygen saturation (SjO(2)) and arterial-jugular bulb oxygen content difference (AjDO(2))]. Jugular bulb oxygen saturation and AjDO(2) were measured before CPB, after 5, 20, 40 min on CPB, at start and end of rewarming, 5 min before the end of CPB and 10 min after CPB. Two-way analysis of variance was used to model the lowest SjO(2) and highest AjDO(2) during CPB, with CPB temperature and blood gas management as contributing factors. RESULTS: Significant changes in SjO(2) were only related to the type of blood gas management, with no significant difference between warm and cold CPB patients. In addition, during rewarming, desaturation (SjO(2)

Post-sternotomy internal mammary arteriovenous fistula.

Arteriovenous fistula from the mammary artery is a rare complication following cardiac surgery. The fistula usually develops within the first 2 weeks after surgery and is initially asymptomatic. Typically, a continuous machinery murmur is heard along the parasternal border of the chest wall. A patient with an arteriovenous fistula between the right internal mammary artery and mammary vein following a combined aortic valve and coronary bypass operation is described. A transthoracic colour Doppler scan led to the diagnosis of the fistula. Because of potential late complications endovascular embolisation of the fistula was successfully performed.

Dobutamine stress echocardiography for the detection of myocardial viability in patients with left ventricular dysfunction taking beta blockers: accuracy and optimal dose.

OBJECTIVE: To assess the accuracy of dobutamine stress echocardiography (DSE) and the optimal dose of dobutamine to detect myocardial viability in patients with ischaemic left ventricular (LV) dysfunction who are taking beta blockers, using the recovery of function six months artery revascularisation as the benchmark. PATIENTS: 17 patients with ischaemic LV dysfunction (ejection fraction < 40%) and chronic treatment with beta blockers scheduled to undergo surgical revascularisation. SETTING: Regional cardiothoracic centre. METHODS: All patients underwent DSE one week before and resting echocardiography six months after revascularisation. A wall motion score was assigned to each segment for each dobutamine infusion stage, using the standard 16 segment model of the left ventricle. The accuracy of DSE to predict recovery of resting segmental function was calculated for low dose (5 and 10 microg/kg/min) and for a full protocol of dobutamine infusion (5 to 40 microg/kg/min). RESULTS: Of the 272 segments studied, 158 (58%) were dysfunctional at rest, of which 79 (50%) improved at DSE and 74 (47%) recovered resting function after revascularisation. Analysis of results with a low dose showed a significantly lower sensitivity and negative predictive value than with a full protocol (47% v 81%, p < 0.001 and 65% v 82%, p < 0.05, respectively). The accuracy in the full protocol analysis was comparable with that reported in patients no longer taking beta blockers but was significantly lower than that in the low dose analysis (78% v 66%, p < 0.001). CONCLUSIONS: Findings suggest that beta blocker withdrawal is not necessary before DSE when viability is the clinical information in question. However, a completed protocol with continuous image recording is required to detect the full extent of viability.

Changes in serum S100beta protein and Mini-Mental State Examination after cold (28 degrees C) and warm (34 degrees C) cardiopulmonary bypass using different blood gas strategies (alpha-stat and pH-stat).

BACKGROUND: The effect of cardiopulmonary bypass temperature and blood gas management on the brain is still controversial. This study was designed to compare the changes in S100beta protein concentration and Mini-Mental State Examination in patients undergoing cold (28 degrees C) vs. warm (34 degrees C) cardiopulmonary bypass using different blood gas strategies (alpha-stat and pH-stat). METHODS: Sixty patients were randomly allocated to one of four equal groups (cold alpha-stat, cold pH-stat, warm alpha-stat, warm pH-stat). Serum S100beta concentrations were measured before CPB, directly after CPB, at 4.5 h and at 24 h after CPB. Mini-Mental State Examination was performed one day before surgery and on day five after the operation. Antegrade warm blood cardioplegia (37 degrees C) was used in all patients. RESULTS: There was no significant difference in postoperative S100beta protein levels between the four groups. Also, there was no interaction between bypass temperature and type of blood gas strategy on S100beta levels after bypass (directly after bypass, 4.5 h and 24 h after bypass). Mini-Mental State Examination score was not affected by blood gas strategy but it was significantly lower in patients undergoing cold cardiopulmonary bypass surgery: median (range), 26 (12-29) vs. 27 (23-30) in warm patients, P = 0.014. There was no significant correlation between Mini-Mental State Examination score 5 days after CPB and S100beta levels at any of the studied time-points after CPB. CONCLUSION: These results support the use of warm CPB (34 degrees C) in patients undergoing coronary artery bypass surgery regardless of the type of blood gas strategy.

[Surgical treatment of carcinoid bronchial tumor]. / Kirurgisk behandling av karsinoid bronkialtumor.

During the period 1977-95, 20 patients underwent surgery for carcinoid tumour in the bronchus at the University Hospital of Trondheim (n = 16) and Innherred County Hospital (n = 4). All the tumours were typical carcinoid tumours. Median age of the patients was 41 years (range 16-78 years). The observation period averaged 7.5 years (0.5-18 years). The most common symptoms were cough, dyspnoea, wheezing and pneumonia. One patient had carcinoid syndrome. Chest X-ray were negative in three of the patients. Bronchoscopy was carried out in all the patients. Biopsies were taken in ten of them, and the diagnosis was conclusive in five cases. Lateral thoracotomy was performed in all the patients. The surgical procedures were lobectomy (15), segmental/wedge resection (3), bronchotomy with tumour resection (1) and sleeve resection (1). 19 patients were still alive at the time of follow-up, with no tumour recurrence. One patient died from cerebral stroke eight years after surgery. Good long-term results were found, and the study supports the use of limited lung resection or bronchoplasty operations to treat carcinoid tumour in the bronchus if the primary tumour is localised and there are no metastases.

The concentration of high molecular weight compounds in interstitial tissue fluid: a study in patients with post-reconstructive leg oedema.

OBJECTIVES: To study whether relative changes in the concentration of different proteins of the subcutaneous interstitial tissue fluid in patients with postreconstructive leg oedema could give information on the integrity of the capillary wall following vascular reconstruction. MATERIALS: Sixteen patients developed ipsilateral leg oedema following femoropopliteal (n = 14) or femorotibial (n = 2) bypass surgery for intermittent claudication (n = 10) or critical lower limb ischaemia (n = 6) caused by obliterating atherosclerosis. METHODS: The leg volume increase was measured according to the formula of a truncated cone. The blister suction method was used for sampling of subcutaneous interstitial tissue fluid. The concentration of albumin, transferrin, immunoglobulin G and alpha 2-macroglobulin of serum and blister fluid was measured with nephelometry. RESULTS: Seven days postoperatively the mean leg volume increase was 32% (19.8%) in the operated leg compared to the contralateral side (p < 0.01). In the blister fluid each of the proteins had a significantly higher concentration in the operated leg compared to the control leg. This concentration difference was relatively larger for the proteins with the highest molecular weight, immunoglobulin G (p = 0.006) and alpha 2-macroglobulin (p = 0.002). CONCLUSIONS: A relatively larger concentration difference of the bigger molecules in the subcutaneous interstitial tissue fluid in patients with post-reconstructive leg ocdema suggests increased capillary permeability to plasma proteins following vascular reconstruction.

[Mitral valve plasty. A 12-year material]. / Mitralklaffeplastikk. Et 12-årsmateriale.

46 patients underwent mitral valve repair at the Regional Hospital in Trondheim/St. Elisabeth Heart Clinic, during the period 1983-95. There were 20 female patients. The valve pathology was ischemic in 40%, rheumatic in 10% and other or unknown in 50%. The surgical technique included commissurotomy (n = 9), ring annuloplasty (n = 18), resection of posterior leaflet (n = 12), Kay annuloplasty (n = 10), shortening of chordae (n = 3) and other techniques (n = 2). Postoperative complications included wound infection (n = 1), pneumonia (n = 1), mediastinitis (n = 1), pleural effusion (n = 5), renal failure (n = 1) and multi-organ failure (n = 1). One patient required re-exploration for postoperative bleeding. Three (6.5%) patients died within 30 days of surgery due to low cardiac output (n = 2) and multi-organ failure (n = 1). Nine patients (21%) died later. At follow up, within one year of surgery, marked functional improvement was registered, with only one patient in NYHA class III and none in class IV.

[Lymphatic complications after lower limb vascular surgery]. / Lymfekomplikasjoner etter karkirurgi på underekstremitetene.

A series of five patients with lymph fistula and two with lymphocele is described. Lymphatic complications in the groin and thigh following infrainguinal arterial surgery may increase the risk of wound infection and prolong the stay in hospital. During operation for lymph fistula and lymphocele, precise identification of the site of lymph leakage during exploration of the wound is mandatory. This can be obtained by intradermal injection of Patent blue 2.5% medially and laterally on the dorsum of the foot approximately one hour before operation. Operation for lymph fistula should be performed as soon as the diagnosis has been verified, especially if a prosthetic graft has been used. A lymphocele should be treated conservatively unless the patient is suffering from localized pain or ischemia of the skin caused by pressure of the underlying swelling.

Protein concentration of subcutaneous interstitial fluid in the human leg. A comparison between the wick technique and the blister suction technique.

The wick technique and the blister suction technique are the most common methods for sampling of subcutaneous interstitial tissue fluid in man. The blister suction technique has the advantage of being less invasive than the wick technique, but the reliability of this method is still controversial. The aim of this study was to evaluate whether the simpler blister suction technique using large (8 mm) blisters could replace the wick technique in the investigation of patients with postreconstructive leg edema. Fifteen patients with ipsilateral leg edema following infrainguinal bypass surgery for lower limb atherosclerosis were investigated. The two different fluid sampling techniques were applied simultaneously on both legs. The concentration of total protein and albumin as well as colloid osmotic pressure of the subcutaneous interstitial tissue fluid in the leg were measured in all fluid samples. Agreement analysis was applied to compare the two methods, while the correspondence between the methods was estimated with linear regression analysis. The agreement index was found to be positive for all variables from the operated as well as from the contralateral control limb. Furthermore, all values were within the agreement limit. The best agreement between the two methods was found for colloid osmotic pressure on the operated side. According to the equation of linear regression, there was a slight overestimation of the wick values compared to the observed blister values. In conclusion, there was a good methodological agreement between the blister suction technique and the wick technique. The less invasive blister suction technique should be regarded as the method of choice for the investigation of subcutaneous interstitial tissue fluid in patients with postreconstructive leg edema.

Lymph drainage and the development of post-reconstructive leg oedema is not influenced by the type of inguinal incision. A prospective randomised study in patients undergoing femoropopliteal bypass surgery.

OBJECTIVES: To see whether the type of groin incision influenced the degree of postoperative leg oedema and the occurrence of lymphatic damage. DESIGN: Prospective randomised clinical study. SETTING: University Department of Surgery. MATERIALS: Twenty-four patients undergoing femoropopliteal bypass reconstruction with either a lateral groin incision (Group A, n = 12) or a direct incision over the femoral vessels (Group B, (n = 12). CHIEF OUTCOME MEASURES: The leg volume increase was measured according to the formula of a truncated cone. Deep venous thrombosis was excluded by air plethysmography and colour-coded Duplex scanning. Lymphatic lesions were detected by lymphoscintigraphy using 99mTc labelled human serum albumin. MAIN RESULTS: One week following vascular reconstruction the median leg volume increase was 24.5% in Group A vs. 23.3% in Group B (NS). Lymphoscintigraphy revealed obstruction of the lymphatics in five patients of Group A vs. three patients of Group B (NS). Neither the occurrence of lymph cysts nor extravasation of lymph differed between the two groups. In seven patients no lymphatic lesion was observed. Patients with interruption of the lymphatics (n = 8) had a higher leg volume increase compared to the remaining patients with no or minor lymphatic lesions, 31.2% vs. 19.6%, respectively (p < 0.05). CONCLUSIONS: Leg oedema and the occurrence of lymphatic damage following femoropopliteal bypass surgery is not reduced by applying a lateral approach to the femoral artery in the groin. However, the higher leg volume increase in patients with lymphatic obstruction indicates that lymphatic damage could play a part in the leg oedema formation.

[Magnetic tomography in the examination of edema and pain in the leg]. / Magnettomografi ved undersøkelse av hevelse og smerte i leggen.

Magnetic resonance imaging (MRI) was used to investigate 38 patients suffering from leg oedema or pain of various etiology. Spin echo series with 10 mm transverse slices of both legs were obtained. Soft tissue changes were visualized best by T2-weighted sequences. Characteristic changes could be observed by MR images of patients with closed compartment syndrome (n = 2), chronic lymph oedema (n = 10) and post-reconstructive leg oedema following vascular surgery (n = 14). MRI can also show typical soft tissue changes in patients with deep vein thrombosis (n = 5) or post-thrombotic syndrome (n = 3). For most of these conditions, the diagnosis can usually be established using simpler methods. However, MRI is an excellent supplementary method for showing soft tissue changes, and is a promising way of investigating conditions that may give rise to leg oedema and pain.

Venous haemodynamics and the occurrence of leg oedema in patients with popliteal aneurysm.

OBJECTIVES: To see whether popliteal aneurysms cause venous obstruction and to investigate leg oedema and DVT following repair. DESIGN: Prospective open clinical study. SETTING: University Department of Surgery. MATERIALS: 8 patients undergoing popliteal aneurysm repair in 9 legs (1 bilateral repair). CHIEF OUTCOME MEASURES: CT and plethysmographic evidence of vein compression, the occurrence of postoperative leg oedema and phlebographic evidence of deep venous thrombosis (DVT). MAIN RESULTS: Preoperative CT investigation showed that the aneurysm compressed the popliteal vein in 6/9 limbs where surgery was planned and in 9/10 limbs with popliteal aneurysms (patent or occluded) of > 2 cm diameter (p < 0.01). However, on the CT image, increased collateral network could be observed and most patients had normal venous drainage prior to operation as assessed by air plethysmography. Postoperatively, leg volume was measured by the formula of a truncated cone. Following vascular reconstruction, leg volume increased by 23%. Except for one patient with a confirmed DVT preoperatively, postoperative venous congestion and DVT was not observed in the operated leg as assessed by phlebography and plethysmography. CONCLUSIONS: Popliteal artery aneurysms "2 cm diameter usually compress and dislocate the popliteal vein prior to operation. However, sufficient venous drainage is maintained, possibly because of an increased collateral venous network. Disruption of lymph channels with secondary lymphoedema is probably the most important mechanism behind the leg swelling observed in patients following popliteal aneurysm repair.