Predictive Modeling of New-Onset Postoperative Diplopia Following Orbital Decompression for Thyroid Eye Disease

PURPOSE

To identify risk factors for the development of new-onset, postoperative diplopia following orbital decompression surgery based on patient demographics, clinical exam characteristics, radiographic parameters, and surgical techniques.

METHODS

We conducted a multi-center retrospective chart review of patients who underwent orbital decompression for thyroid eye disease (TED). Patient demographics, including age, gender, smoking history, preoperative exophthalmometry, clinical activity score (CAS), use of peribulbar and/or systemic steroids, and type of orbital decompression were reviewed. Postoperative diplopia was determined at a minimum of 3 months postoperatively and before any further surgeries. Cross-sectional area ratios of each extraocular muscle to orbit and total fat to orbit were calculated from coronal imaging in a standard fashion. All measurements were carried out using PACS imaging software. Multivariable logistic regression modeling was performed using Stata 14.2 (StataCorp, College Station, TX).

RESULTS

A total of 331 patients without preoperative diplopia were identified. At 3 months postoperatively, 249 patients had no diplopia whereas 82 patients developed diplopia. The average postoperative follow-up was 22 months (range 3-156) months. Significant preoperative clinical risk factors for postoperative diplopia included older age at surgery, proptosis, use of peribulbar or systemic steroids, elevated clinical activity score, and presence of preoperative compressive optic neuropathy. Imaging findings of enlarged cross-sectional areas of each rectus muscle to the overall orbital area also conferred a significant risk of postoperative diplopia. Regarding surgical factors, postoperative diplopia was more common among those undergoing medial wall decompression, bilateral orbital surgery, and balanced decompression, whereas endoscopic medial wall decompression was found to be relatively protective.

CONCLUSIONS

This study identifies risk factors associated with the development of diplopia following orbital decompression using multivariable data. This study demonstrates that several characteristics including age, clinical activity score, the cross-sectional muscle to orbit ratios, in addition to the type of orbital decompression surgery, are predictive factors for the development of new-onset postoperative diplopia.

Differentiating intradiploic orbital dermoid and epidermoid cysts utilizing clinical features and machine learning

Purpose

The purpose of this study was to characterize intradiploic dermoid and epidermoid orbital cysts to determine any differences in clinical, radiographic, or surgical features.

Methods

A retrospective review was performed of patients presenting with intradiplopic dermoid or epidermoid cysts. Additionally, a complete review of the literature was performed to identify cases of intradiplopic orbital dermoid and epidermoid cysts. Data collected included age, sex, presenting symptoms, location of intradiplopic cyst, ophthalmic findings, treatment, and follow-up. Clinical features of dermoid versus epidermoid cyst were compared. Additionally, machine-learning algorithms were developed to predict histopathology based on clinical features.

Results

There were 55 cases of orbital intradiploic cysts, 49 from literature review and six from our cohort. Approximately 31% had dermoid and 69% had epidermoid histopathology. Average age of patients with dermoid cysts was significantly lesser than that of patients with epidermoid cysts (23 vs. 35 years, respectively; P = 0.048). There was no difference between sex predilection, presenting symptoms, radiographic findings, or surgical treatment of dermoids and epidermoids. The majority of patients (64%) underwent craniotomy for surgical removal. Machine-learning algorithms KStar and Neural Network were able to distinguish dermoid from epidermoid with accuracies of 76.3% and 69%, respectively.

Conclusion

Orbital intradiploic cysts are more commonly epidermoid in origin. Dermoid cysts presented in younger patients; however, there were no other significant differences in features including ophthalmic or radiographic findings. Despite similar features, machine learning was able to identify dermoid versus epidermoid with good accuracy. Future studies may examine the role of machine learning for clinical guidance as well as new surgical options for intervention.

Hypothalamic Pilomyxoid Astrocytoma in a Child with Lipodystrophy

Pilomyxoid astrocytoma is a rare form of pediatric CNS malignancy first classified in 2007 by the World Health Organization. The tumors are similar to pilocytic astrocytomas, sharing both some imaging and histologic traits. However, pilomyxoid astrocytomas portend a more ominous prognosis, with more aggressive local tendencies and a greater proclivity for leptomeningeal spread. Although tissue sampling is ultimately required to differentiate pilocytic astrocytomas and pilomyxoid astrocytomas, some imaging features can be used to suggest a pilomyxoid astrocytoma, including homogeneous enhancement, leptomeningeal seeding, and lack of intratumoral cysts. In this article, a case of a hypothalamic pilomyxoid astrocytoma is described, in which the presenting disorder was profound generalized lipodystrophy. The aforementioned imaging characteristics of pilomyxoid astrocytomas are reviewed, as are the pathologic features of such tumors, including their angiocentric cellular arrangement and myxoid background.

Optic Nerve Choristoma Mimicking a Neurenteric Cyst

Optic nerve choristomas are rare entities in which a developmental focus of histologically normal tissue is abnormally located within or along a segment of the optic nerve. Although benign, choristomas may demonstrate slow growth, ultimately resulting in visual field deficits due to compression of the adjacent nerve in the few cases reported in the anterior fossa. Choristomas may have cystic components, though this has not been described in such lesions along the optic nerve. Here, a predominantly cystic optic nerve choristoma is described, with radiologic features mimicking those of an anterior cranial fossa neurenteric cyst. The case highlights the radiology-pathology correlates of choristomas and reviews the surgical approach and management of patients with such lesions.

EPEN-35. PERITONEAL CARCINOMATOSIS OF ANAPLASTIC EPENDYMOMA: FIRST REPORTED CASE

Peritoneal Carcinomatosis of anaplastic ependymoma is not a previously reported entity. The authors report on a child with multiple successfully treated brain and spine disease occurrences who subsequently develops carcinomatosis of the abdomen and no evidence of CNS recurrence. Ependymoma accounts for up to 10% of childhood CNS tumors diagnosed in the United States with a median age of 51–71 months. Typical locations are based on age. Disease is typically treated with surgical resection followed by radiation. The role of chemotherapy has not been proven but currently being examined with open clinical trials. We will describe patient’s presentations, clinical treatment and recurrence with subsequent treatment and outcome at time of meeting.

Exophytic Lumbar Vertebral Body Mass in an Adult with Back Pain

Chordomas are rare primary bone malignancies derived from notochord remnants. The tumors often are slow-growing and often present with indolent, nonspecific symptoms. Nevertheless, chordomas are locally aggressive and highly prone to local recurrence, necessitating precise planning before biopsy and/or surgical resection. Familiarity with the imaging features of chordomas is, therefore, essential. This case highlights the typical imaging and pathologic features of a spinal chordoma as well as the surgical approach and the patient's subsequent outcome.

Mixed Solid and Cystic Mass in an Infant

Desmoplastic infantile tumors are rare supratentorial brain tumors that occur in pediatric patients. Desmoplastic infantile tumors are made up of 2 subtypes: desmoplastic infantile gangliogliomas and desmoplastic infantile astrocytomas. Desmoplastic infantile tumors are often identifiable on imaging on the basis of multiple characteristics. Nevertheless, pathologic analysis is required to confirm the diagnosis, particularly when the imaging features are atypical. Here, the radiology findings, surgical approach and subsequent management, and pathology of a desmoplastic infantile ganglioglioma are described.

[Pulmonary embolism caused by aspergillosis (so-called fungal embolism)]

A 71-year-old man developed a cardiac tumour in the right ventricle and a pulmonary embolism caused by aspergillosis after implantation of a pacemaker because of arrhythmia. Repeated revisions during pocket infections. Emergency operation and tricuspid valve replacement with a Carpentier Edwards xenograft. The pacing electrodes and the endocardium were infected by Aspergillus in form of an aspergilloma. This case is an example of the rare condition of a pulmonary embolism with pure fungal material.

Peripheral arterial disease in diabetes mellitus type 1 and type 2: are there different risk factors?

BACKGROUND

Diabetic patients have increased prevalence of peripheral arterial disease (PAD). It is not clearly shown whether the prognostic factors are identical in relation to the type of diabetes. This study was done to compare the associations of PAD with risk factors and with micro- and macrovascular complications of inpatients with type 1 and type 2 diabetes.

METHODS

In a retrospective cross-sectional study 1087 patients with type 1 diabetes and 1060 patients with type 2 diabetes were examined. PAD was diagnosed when ankle-brachial-pressure-index (ABI) was < 1.0. In cases with incompressible arteries (mediasclerosis) pulse wave forms were analyzed. Multivariate logistic regression analysis was applied to evaluate the impact of different variables on PAD risk, after adjusting for different variables separately.

RESULTS

In both types of diabetes (type 1 vs. type 2) PAD risk (odds ratio; OR) was increased in the presence of coronary heart disease (OR 9.3 vs. 3.5), diabetic nephropathy (OR 3.0 vs. 2.8), neuropathy (OR 7.9 vs. 1.8), foot ulceration (OR 8.9 vs. 5.5), increased daily insulin requirement > 0.6 mu/kg b.w. (OR 5.2 vs. 2.9), diabetes duration of 20-29 years (OR 28.9) and > 30 years (OR 51.1) in type 1 diabetes, and diabetes duration of 10-19 years (OR 3.8) and > 20 years (OR 4.3) in type 2 diabetes. In type 2 diabetes, PAD risk was associated with microalbuminuria (OR 2.1), macroalbuminuria (OR 3.3), background retinopathy (OR 1.9), proliferative retinopathy (OR 2.8), increased triglycerides (TG) (OR 1.7) and decreased HDL-cholesterol (HDL-C > 0.90 mmol/l: OR 0.49).

CONCLUSIONS

PAD risk factors and micro- and macrovascular comorbidity are very similar in type 1 and type 2 diabetes.

Sarcoma associated with silver coated mechanical heart valve prosthesis

Sarcomas can develop in association with foreign material (eg, from Dacron vascular prostheses). We report on a left atrial rhabdomyosarcoma that developed within 1 year of mitral valve replacement by a Silzone-coated St. Jude Medical mechanical heart valve. Tumor resection and redo valve replacement were done. Six months later the patient was alive, but an echocardiogram showed tumor recurrence. Although this is a single case, an association between heart valve prostheses and malignant tumors should be considered.

Emergency coronary artery bypass grafting: does excessive preoperative anticoagulation increase bleeding complications and transfusion requirements?

Patients requiring urgent surgical revascularization due to unstable coronary artery disease are usually pretreated with multiple antithrombotic drugs. The perioperative risks of this type of treatment were investigated in 123 patients who underwent emergency coronary artery bypass grafting (CABG) at our institution.Eighty-two patients (group A) received heparin and acetylsalicylic acid solely and 41 patients (group B) received additionally ADP-receptor antagonists (82.9%), glycoprotein IIb/IIIa inhibitors (12.2%) or thrombolysis (14.6%) preoperatively. Both groups were similar regarding demographic data and overall clinical status. Preoperative coagulation parameters and intraoperative characteristics were comparable. Blood loss via chest tubes was not significantly different between groups. Transfusion of red blood cells and fresh frozen plasma were slightly, but not significantly increased in group B. Transfusion of pooled platelets was low in general and similar in both groups. Re-exploration rate, medium intensive care unit and hospital stay as well as perioperative mortality were comparable.Excessive antithrombotic pretreatment seems to bear no additional risk in emergency CABG and may be beneficial in this setting.

Stunned myocardium after off-pump coronary artery bypass grafting

Off-pump coronary artery bypass grafting is increasingly performed. Because these procedures are associated with temporary myocardial ischemia, there is a risk of ischemia-related complications. We report two cases of myocardial stunning after off-pump coronary artery bypass grafting using the Octopus tissue stabilizer. On the basis of our experiences, means to prevent stunning are discussed.

Anticoagulation in extracorporeal circulation using recombinant hirudin: a case report

Heparin-induced thrombocytopenia (HIT) is a severe complication following the application of heparin; antibodies against complexes of heparin and PDF4 initiate activation of platelets. This may lead to massive thrombembolism, which is associated with a slight and transient drop of platelets in HIT I or a drop below 50% after approximately 5 days in HIT II. Further administration of heparin has to be strictly avoided in these patients. Immunologic evidence for HIT can easily be obtained by the heparin-induced platelet aggregation assay. If anticoagulation is necessary, different, alternative drugs are available. Recombinant hirudin (r-hirudin) is a well-established drug for safe anticoagulation. Monitoring is possible by estimating the plasma level of r-hirudin from the ecarin-clotting time. We report a case of a patient with prosthetic aortic valve endocarditis and HIT II who suffered from massive postoperative bleeding requiring massive substitution of blood components and coagulants caused by free circulating r-hirudin due to the use of a hemofilter.

Pumpless arteriovenous extracorporeal lung assist: what is its role?

Extracorporeal lung assist (ECLA) is an established treatment of severe pulmonary failure. Since extracorporeal perfusion is applied in a long-term fashion in this setting, the negative impact on blood compounds is of tremendous importance. Pumpless arteriovenous ECLA (av-ECLA) is an alternatively introduced technique that focuses on reduced blood traumatization. However, due to determining technical and physiological aspects, its clinical application is limited to a highly selected group of patients. Membrane oxygenators with minimal pressure gradients, as well as stable patients' haemodynamics providing a sufficient cardiac output, are the most important prerequisites. With respect to recent reports, characteristic features of av-ECLA, with special emphasis on its physiological background, are reviewed. Accordingly, reasonable indications for its beneficial use are discussed. It is concluded that av-ECLA is a feasible technique when its limitations are accepted. For adequate clinical use, more data concerning indications, as well as time- and technique-related directions are required.

Severe heart valve calcification in a young patient with Werner syndrome

Werner syndrome is a rare autosomal recessive disorder characterized by the appearance of premature aging. We report on severe aortic and mitral valve calcification in an 18-year-old girl, necessitating double valve replacement. These special cardiovascular findings are discussed with regard to diagnosis and treatment.

Hemostasis management by use of Hepcon/HMS: increased bleeding without increased need for blood transfusion

BACKGROUND

Extracorporeal circulation forces complete anticoagulation, most frequently achieved by complete heparinization. Activated clotting time (ACT) is the gold standard for monitoring, although there is a lack of correlation between heparin plasma level and ACT. Several systems for the estimation of free heparin have been developed: in this study we focused investigating on the influence of the Hepcon/HMS system on postoperative bleeding and transfusion requirements.

METHODS

114 patients were randomly assigned to one group monitored by use of Hepcon/HMS (group hepcon) and another group by use of ACT (ACT group); 7 patients were excluded due to re-exploration. 12 patients did not receive aprotinin; this part of the study was stopped early due to massive increased bleeding. 46 and 49 patients of groups hepcon and ACT, respectively, received aprotinin.

RESULTS

Using aprotinin, in group hepcon total administered heparin was elevated by 13 % in contrast to group ACT while administered protamine was reduced by 20%. The ratio of antagonization was 82 +/- 17 % and 51 +/- 12 %, respectively. Coagulation parameters were not influenced except for increased postoperative ACT and PTT in the hepcon group. Bleeding of patients in that group was significantly increased during the first 6 hours, which led to an increased autologous retransfusion. Need for substitution of other blood components was not increased postoperatively.

CONCLUSIONS

Use of the Hepcon/HMS-system for monitoring of heparinization during extracorporeal circulation is possible without increased risk of thromboembolism. Postoperative blood loss was slightly but significantly increased but there was no need for more heterogenous transfusion.

Controlled limb reperfusion in patients having cardiac operations

HYPOTHESIS

Severe limb ischemia in patients having cardiac operations may occur after intraaortic balloon pump insertion, prolonged femoral vessel cannulation, percutaneous cardiopulmonary bypass, dissecting aneurysms, or emboli. Normal blood reperfusion can cause a postischemic syndrome that increases morbidity and mortality. This clinical study is based on an experimental infrastructure patterned after controlled cardiac reperfusion. (1) It tests the hypothesis that controlled limb reperfusion (i.e., modifying the composition of the initial reperfusate and the conditions of reperfusion) reduces the local and systemic complications seen after normal blood reperfusion. (2) It reports initial clinical application of this strategy in three cardiac surgery centers.

METHODS

Controlled limb reperfusion was applied to 19 patients with signs of severe prolonged unilateral or bilateral ischemia (including paralysis, anesthesia, and muscle contracture); six patients (32%) were in cardiogenic shock. The mean ischemic duration was 26 +/- 6 hours. The reperfusion method includes a 30-minute infusion into the distal vessels of a normothermic reperfusate solution mixed with the patient's arterial blood (obtained proximal to the obstruction) in a 6:1 blood/reperfusate ratio. Data are mean +/- standard error of the mean.

RESULTS

Sixteen patients (84%) survived with salvaged and functional limbs at the time of discharge. No renal, cardiac, pulmonary, cerebral, or hemodynamic complications developed in the survivors. The three deaths occurred in patients undergoing controlled limb reperfusion while in profound postoperative cardiogenic shock; neither postischemic edema nor contracture developed in any of them.

CONCLUSIONS

These findings show that controlled limb reperfusion can be applied readily with standard equipment that is used for cardiac surgery and may salvage limbs while reducing postreperfusion morbidity and mortality.

Submitral left ventricular tuberculoma

A 62-year-old woman suffered from increasing dyspnea and an impaired general condition. Chest roentgenograms and echocardiogram showed a dense mass at the left atrioventricular junction resulting in the preoperative working diagnosis of a myocardial myxoma. Intraoperatively, an isolated tuberculoma was found caudal to the posterior leaflet of the mitral valve. This case report describes the successful surgical and postoperative medical treatment of an isolated myocardial tuberculoma.

Role of pericardial constraint for right ventricular function in humans

STUDY OBJECTIVE

To analyze the extent of pericardial constraint on right ventricular function in humans.

PATIENTS AND METHODS

Twenty patients, 59 +/- 2 (mean +/- SEM) years old, undergoing coronary bypass surgery. Right ventricular volumes and pressures were evaluated using a rapid response Swan-Ganz thermodilution catheter.

INTERVENTIONS

Parameters were determined before and after pericardiotomy, both before and during increased right ventricular systolic pressure by partial compression of the pulmonary artery (before pulmonary compression: 25 +/- 1 mm Hg; during: 39 +/- 1 mm Hg).

RESULTS

Pericardiotomy alone did not significantly affect right ventricular end-diastolic volume (before: 79 +/- 4 mL m-2; after: 78 +/- 3 mL m-2), right ventricular ejection fraction (before: 48 +/- 1%; after: 48 +/- 2%), and right atrial pressure (before: 4.3 +/- 0.8 mm Hg; after: 4.3 +/- 0.7 mm Hg). Before pericardiotomy, the increase in right ventricular afterload significantly increased right atrial pressure (to 5.5 +/- 0.7 mm Hg, p < 0.05) and reduced right ventricular ejection fraction (to 43 +/- 2%, p < 0.01). Right ventricular end-diastolic volume remained unchanged. After pericardiotomy, the increase in right ventricular afterload significantly increased right ventricular end-diastolic volume (to 85 +/- 3 mL m-2, p < 0.01) and also reduced right ventricular ejection fraction (to 42 +/- 2%, p < 0.01), while right atrial pressure was not significantly changed. During increased right ventricular afterload, the right ventricular diastolic pressure-volume relation was shifted rightward.

CONCLUSIONS

At normal levels of right ventricular diastolic filling, the pericardium does not exert constraining effects on right ventricular function. However, with increasing levels of right ventricular preload, pericardial constraint significantly influences right ventricular function in humans.

[An isolated tuberculoma in the left ventricle]

In the course of 8 weeks, a 62-year-old woman with chronic bronchitis developed increasing dyspnoea on effort and reduced well-being. The chest radiograph revealed a round focus, 2 x 3 cm, in the region of the left ventricle which, from the results of echocardiography and left-heart catheterization, suggested myxoma. At open-heart surgery under extracorporeal circulation an encapsulated tumour was found on the mural leaflet of the mitral valve, directly caudal of the atrioventricular plane. On opening, the capsule contained dough- or paste-like, yellowish-white substance with scattered polygonal granules, typical of a tuberculoma. The entire contents and capsule were excised. Immediately after operation tuberculostatic treatment was initiated (three times daily ethambutol, 400 mg, and once daily rifampicin, 600 mg, and isoniazid, 300 mg), even though acid-fast rods were not demonstrated histologically and by culture. Polymerase chain reaction, however, established the presence of Mycobacterium tuberculosis in the resected material. There was no evidence of florid tuberculosis in the subsequent course.

New surgical treatment for severe limb ischemia

Revascularization after prolonged complete limb ischemia may result in severe damage to skeletal muscle and systemic alterations (postischemic syndrome). Our previous experimental studies have shown that this injury can be reduced substantially by treating the jeopardized extremity by controlling the conditions of reperfusion and composition of the initial reperfusate. In the present study this concept of controlled limb reperfusion was applied in patients with prolonged severe limb ischemia. Controlled limb reperfusion was used in 14 patients after prolonged complete uni- or bilateral ischemia. The ischemic interval ranged from 5 to 21 h. Two patients were in cardiogenic shock, 11 had associated cardiac disease, and seven coexistent peripheral vascular disease. After systemic heparinization, standard thromboembolectomy was done using a Fogarty catheter. Cannulas were placed into the iliac, profunda, and superficial femoral arteries and were connected to a reperfusion set. Oxygenated blood was drawn from the iliac artery and mixed with an asanguineous solution (ratio 6:1). This controlled reperfusate was delivered into the profunda and superficial femoral arteries using a single rollerpump. The system allows control of the composition of the reperfusate (calcium, pH, osmolarity, glucose, substrate, pO2, free radical scavengers) and the conditions of reperfusion (pressure, flow, temperature). After 30 min of controlled limb reperfusion, the cannulas were removed and normal blood reperfusion started. All 12 patients who were stable hemodynamically before the operation survived the revascularization. Eleven patients, including one with acute aortic occlusion for several hours, were discharged with functional recovery of their extremities. Despite the severe ischemic insult, controlled limb reperfusion avoided amputation and profound systemic complications. Two patients who were in cardiogenic shock preoperatively died from progressive cardiac failure. We conclude that controlled arterioarterial limb reperfusion may reduce the local manifestations of the postischemic syndrome after prolonged periods of ischemia, may salvage limbs thought previously to be damaged irreversibly by prolonged ischemia, and can be done easily in the operating room.

Immediate postoperative recovery of regional wall motion after unilateral and bilateral internal mammary artery revascularization

Within the last few years the importance of the internal mammary artery (IMA) for coronary revascularization has increased rapidly. Although there is no doubt about the superior long-term patency of this artery in comparison to saphenous vein grafts, the discussion about early postoperative results is controversial. The aim of the present study was to assess segmental wall motion after unilateral and bilateral IMA revascularization. Thirty-three patients who underwent elective myocardial revascularization were examined. In addition to vein grafts, bilateral IMA grafts were used in 8 patients and unilateral ones in 25 patients. Myocardial segmental wall motion was assessed by transesophageal echocardiography perioperatively. Myocardial protection was achieved by standard cold blood cardioplegia. Global left ventricular function remained unchanged postoperatively (4 h) in both groups (unilateral IMA: 52.8% +/- 7.1% vs 49.8% +/- 11.1%; bilateral IMA; 47.7% +/- 8.7% vs 48.7% +/- 7.7%, ns). Anterior wall motion (left IMA grafts to left anterior descending artery (LAD) was decreased early postoperatively (30 min) in both groups (unilateral IMA: 50.9% +/- 15.3% vs 37.8% +/- 14.5%; bilateral IMA: 47.3% +/- 20.1% vs 30.4% +/- 8.5%, P < 0.05). Posterior wall motion was decreased in the bilateral IMA group (right IMA to right coronary artery (RCA), 47.8% +/- 7.2% vs 28.0% +/- 8.9%, P < 0.05) and remained unchanged in the unilateral IMA patients (vein grafts to RCA, 39.5% +/- 9.9% vs 41.4% +/- 17.5%, ns). Internal mammary artery revascularization may result in deterioration of segmental myocardial function in the early (< 4 h) postoperative period. Bilateral IMA grafts should therefore be used with caution in patients with impaired ventricular function.

Studies of reperfusion injury in skeletal muscle: controlled limb reperfusion to reduce post-ischaemic syndrome

Revascularization after prolonged complete limb ischaemia may result in both severe damage to skeletal muscle and various systemic manifestations of the postischaemic syndrome. Previous experimental studies performed by the authors have shown that these are caused, to a large extent, by normal reperfusion at normal systemic pressure and that this additional injury can be substantially reduced by controlled reperfusion of the revascularized limb before restoration of the normal circulation. This treatment includes control of the conditions of reperfusion and composition of the initial reperfusate. In the present study, this concept of controlled limb reperfusion was applied to patients with prolonged severe lower limb ischaemia. Controlled limb reperfusion was used in 11 patients after prolonged complete unilateral or bilateral ischaemia. The ischaemic interval ranged from 5 to 21 h. Two patients were in cardiogenic shock, ten had a history of associated cardiac disease and seven coexistent peripheral vascular disease. After systemic heparinization, thromboembolectomy was undertaken using a Fogarty catheter. Cannulas were placed in the iliac, profunda and superficial femoral arteries and connected to a reperfusion set. Oxygenated blood was drawn from the iliac artery and mixed with an asanguineous solution (ratio 6:1). This controlled reperfusate was returned to the profunda and superficial femoral arteries using a single roller pump. The system allows control of both the composition of the reperfusate (Ca2+, pH, osmolarity, glucose, substrate, PO2, free radical scavengers) and the conditions of reperfusion (pressure, flow, temperature). After 30 min of controlled limb reperfusion, the cannulas were removed, the arteriotomy closed and normal blood reperfusion started.(ABSTRACT TRUNCATED AT 250 WORDS)

Changing patterns of patients undergoing emergency surgical revascularization for acute coronary occlusion. Importance of myocardial protection techniques

Between 1977 and 1992 a total of 163 consecutive patients underwent emergency coronary artery bypass grafting after acute coronary occlusion (94% after failed angioplasty). Patients were divided into four groups according to the method used for myocardial protection. The crystalloid cardioplegia group included 30 patients operated on from 1977 to 1980; the hypothermic fibrillation group included 60 patients (1980 to 1986); the blood cardioplegia group included 36 patients (1986 to 1989); and the blood cardioplegia with controlled reperfusion group included 37 patients (1989 to 1992). Preoperative data, ischemic time interval, collateral blood flow, intraoperative data, regional wall motion, global ejection fraction, myocardial infarct-specific electrocardiographic changes, enzyme release, rhythm disturbances, mortality, prevalence of intraaortic balloon pumping, and inotropic support were assessed in this retrospective study. Our data indicate that the current spectrum of patients undergoing emergency coronary artery bypass grafting after acute coronary occlusion are at a significantly higher risk compared with those 15 years ago, that is, increase in age (53 +/- 1 versus 59 +/- 2 years; p < 0.05), three-vessel disease (38% versus 3%; p = 0.004), acute occlusion of the left main coronary artery (11% versus 0%; p = 0.02), preoperative cardiogenic shock (35% versus 3%; p = 0.007), prevalence of acute two-vessel occlusion (22% versus 3%; p = 0.05), prevalence of previous infarction (59% versus 23%; p = 0.04), and duration of ischemia (3.0 +/- 0.2 versus 4.1 +/- 0.3 hours; p < 0.05). Despite the increase in patients with severely compromised ventricular function during recent years, the overall hospital mortality decreased to 5% (2/37) when maximal protection of the ischemic and remote myocardium was performed (preoperative intraaortic balloon pump, combined antegrade/retrograde substrate-enriched blood cardioplegia, warm induction, controlled reperfusion, prolonged vented bypass). Single-vessel disease was always associated with a low mortality, whereas mortality could be reduced with controlled blood cardioplegia in patients with multivessel disease (6%) and cardiogenic shock (15%). The immediate return of regional contractility in the previously ischemic area after controlled reperfusion might serve as an explanation for these favorable results. After unmodified blood reperfusion, normokinesis or slight hypokinesis occurs in only 34% to 46% in the early postoperative period (1 to 4 weeks) in comparison with 86% after controlled blood cardioplegia reperfusion (p < 0.05). We conclude that there is a significant increase in risk factors in patients undergoing emergency coronary artery bypass grafting and that improved methods of intraoperative myocardial protection are needed for these compromised patients.

Left main coronary artery stenosis after aortic valve replacement: genetic disposition for accelerated arteriosclerosis after injury of the intact human coronary artery?

BACKGROUND

Left main coronary artery stenosis is a rare but life-threatening complication after aortic valve replacement because of coronary perfusion-related trauma to the vessel wall with cannulation of the coronary ostia. We investigated whether this complication still occurs in the 1990s despite the use of more advanced catheter materials and modern surgical preservation techniques.

METHODS

Four years after identification of the first two cases in 1987, five further patients had developed left main coronary artery stenosis after aortic valve replacement (incidence, 0.9%) at the cardiothoracic clinic of the J.W. Goethe University and were studied for contributing factors.

RESULTS

Severe coronary ostial stenosis developed within 1 to 6 months after aortic valve replacement. In one such case, intimal proliferation was seen in a biopsy specimen that was comparable to the restenosis induced by coronary angioplasty. The clinical characteristics of the patients developing the complication, the surgical technique, and the intraoperative course did not differ from the other patients. However, five of the seven patients (71%) had a common genetic trait concerning their apolipoprotein E genotype (the epsilon 4 allele) that is normally present in only 10% to 15% of patients screened (P < 0.01).

CONCLUSIONS

These lesions seem to result from a uniform response of the vessel wall to injury. Their incidence is probably related in part to the degree of injury after trauma to the coronary ostia during cannulation for myocardial protection. Patients with the epsilon 4 allele might be genetically predisposed for a pathologically increased response of proliferative repair mechanisms after arterial injury. The complication can be avoided by not instrumenting the coronary ostia for direct antegrade cardioplegia but using retrograde delivery as an alternative method of myocardial protection.