New approach to patency and flow assessment after left internal thoracic artery hypoperfusion syndrome with additional saphenous vein graft to the left anterior descending artery with phase-contrast magnetic resonance angiography

OBJECTIVE

Perioperative and early postoperative flow reduction of a left internal thoracic artery conduit is a rare complication of myocardial revascularization and may lead to the potentially fatal left internal thoracic artery hypoperfusion syndrome. It has been advocated that an additional vein graft be placed to the distal left anterior descending artery to provide sufficient myocardial perfusion. Some evidence exists, however, that this high-flow vein might lead to competing or even backward flow through the internal thoracic artery.

METHODS

In the past 2 years, 21 patients received an additional vein graft to the distal left anterior descending artery for left internal thoracic artery hypoperfusion syndrome. Nineteen of these patients were available for magnetic resonance imaging. Early (< 6 months) and late (> 12 months) postoperative flow measurements, both in the left internal thoracic artery and in the saphenous vein grafts, were performed by means of conventional and a segmented k-space phase-contrast magnetic resonance angiography technique.

RESULTS

Early magnetic resonance examinations indicated that all conduits had adapted to the coronary flow type with predominant diastolic perfusion. Patency rate both at the early and at the late study was 100%. No concurrent flow, flow reversal, or steal phenomena were observed. Mean flow rates were 49.2 ml/min for the left internal thoracic artery and 72.6 ml/min for the saphenous vein graft.

CONCLUSION

On the basis of the flow data obtained with magnetic resonance angiography, the use of an additional saphenous vein graft as the treatment of choice in left internal thoracic artery hypoperfusion syndrome does not lead to occlusion of the artery. Conduit flow adaptation to the diastolic predominance occurs in the first 6 months after operation.

Temporary loss of cardiac autonomic innervation after the maze procedure

OBJECTIVE

Blunted sinus node response to exercise has been reported after the maze operation. We suggested the autonomic vegetative function of the heart to be disturbed after the maze procedure.

METHODS

17 patients, mean age 63 +/- 15 years, with chronic atrial fibrillation for 49 +/- 46 months (range 5-65) underwent the maze procedure during mitral valve surgery. Bicycle stress test, 24-h electrocardiography and heart rate variability were analysed in 11 patients after three and in six after 14 +/- 3 months. Spectral analysis within two frequency bands, vector analysis of the main circular resultant and influence of orthostasis and Valsalva manoeuvre on different R-R intervals were calculated.

RESULTS

One patient died from a perioperative ischaemic stroke. At follow-up, all patients were in sinus rhythm. Heart rate reached 84 +/- 14%, the mean circular resultant was 60 +/- 48%, the ratio of the longest to the shortest R-R interval during the Valsalva manoeuvre was 92 +/- 8% and the ratio of maximal to minimal R-R interval after orthostasis was 98 +/- 4% of the age-adjusted normal value. Maximal workload was 116 +/- 31 watts. All patients had abnormal heart rate variability. Heart rate variability was significantly more blunted after three months, than after 14 months (P < 0.05). The minimal heart rate and the difference between the maximal and the minimal heart rate during the 24-h electrocardiography were significantly correlated to the number of normal physiological tests (r = -0.52; P < 0.05; r = 0.71; P < 0.005); for the maximal heart rate, there was a positive trend only (r = 0.44; P = 0.07).

CONCLUSIONS

Early after the maze procedure, a nearly total denervation of the sinus node is present, similar as seen after heart transplantation, with partial restoration of the autonomic function after one year. The exercise capacity of the patients was satisfactory.

In situ repair of aortobronchial, aortoesophageal, and aortoenteric fistulae with cryopreserved aortic homografts

PURPOSE

The surgical treatment of fistulae that originate from aortic aneurysms or prosthetic aortic grafts carries a high mortality rate. We investigated whether in situ repair with cryopreserved aortic homografts would improve the outcome.

METHODS

Between April 1994 and June 1996, 11 patients (mean age, 62 +/- 10 years) with aortobronchial, aortoesophageal, or aortointestinal fistulae originating from mycotic aneurysms (five of 12) or prosthetic aortic grafts (six of 12) underwent in situ replacement of the thoracic (seven of 10) or abdominal (four of 10) aorta with homografts. Emergency surgery was performed in eight of 11 patients (73%).

RESULTS

The hospital mortality rate was 9%; there was one sudden cardiac death on the seventh postoperative day. The mean hospital stay was 42 +/- 26 days (range, 21 to 90 days). After surgery, antibiotics were given for 38 +/- 6 days (range, 28 to 42 days). Neither reinfection, suture line rupture, nor anastomotic aneurysms were observed by magnetic resonance angiography, computed tomography, angiography, or transesophageal echocardiography after 14.3 +/- 8.2 months (range, 6 to 31 months). In one patient, percutaneous vascular stent placement was necessary after 18 months for an anastomotic stenosis of a thoracic homograft.

CONCLUSIONS

In situ repair with cryopreserved aortic homografts seems to be a promising step in the treatment of aortobronchial, aortoesophageal, and aortointestinal fistulae. This technique has a low operative mortality rate and may prevent reinfection.

Reoxygenation of hypoxic human umbilical vein endothelial cells activates the classic complement pathway

BACKGROUND

Ischemia-reperfusion injury leads to the activation and endothelial deposition of complement. We investigated whether exposure of human umbilical vein endothelial cells (HUVECs) to hypoxia and/or reoxygenation activates complement and decreases HUVEC-surface expression of the C3 regulatory proteins CD46 and CD55.

METHODS AND RESULTS

HUVECs were subjected to 0, 12, or 24 hours of hypoxia (O2 = 1%) and then reoxygenated for 3 hours (O2 = 21%) in the presence of 30% human serum. C3 deposition and HUVEC-surface expression of CD46 and CD55 were evaluated by ELISA and flow cytometry. C3 deposition on HUVECs subjected to 12 or 24 hours of hypoxia followed by 3 hours of reoxygenation was significantly greater than normoxic HUVECs. Inhibition of the classic but not the alternative complement pathway during reoxygenation attenuated C3 deposition. Western blot analysis of HUVEC lysates under reducing conditions demonstrated significantly increased iC3b deposition in hypoxic/reoxygenated HUVECs compared with normoxic HUVECs. FACS analysis confirmed iC3b deposition. HUVEC-surface expression of CD46 and CD55 increases after hypoxia and/or reoxygenation.

CONCLUSIONS

We conclude that (1) hypoxia and reoxygenation of HUVECs significantly increases iC3b deposition on HUVECs, (2) C3 deposition after hypoxia and reoxygenation is largely mediated by the classic complement pathway, and (3) HUVEC-surface expression of CD46 and CD55 increases after hypoxia and reoxygenation. These data demonstrate that hypoxia and reoxygenation of human endothelial cells activates the classic complement pathway despite an increase in complement C3 regulatory proteins.

[Aortic valve insufficiency in Crohn disease]

We report on a 39-year-old man with Crohn's disease who was admitted with cardiogenic shock after a short history of progressive dyspnea. Echocardiographic examination (transthoracic echocardiography) showed severe aortic regurgitation, mild mitral regurgitation, and enlargement of the sinus of Valsalva and of the ascending aorta at the level of the right pulmonary artery. The left ventricular ejection fraction was 30%. After aortic valve replacement, histologic examination of the ascending aorta showed chronic aortitis resembling syphilitic aortitis (serology for syphilis was negative) and HLA B27 related aortitis. The aortic valve showed deformation and thickening of the cusps by fibrous tissue without evidence of endocarditis. The patient remained well after surgery and echocardiographic examination 6 months later showed normal function of the aortic valve prosthesis. The diameter of the sinus of Valsalva and of the ascending aorta was slightly bigger, possibly indicating ongoing destruction. The left ventricular ejection fraction nearly normalized. It seems possible that this type of aortitis, characterized by its proximity to the valve ring, is another extraintestinal cardiac manifestation of Crohn's disease. The possibility of ongoing destruction of the sinus of Valsalva and of the ascending aorta after valve replacement makes regular echocardiographic control necessary.

Hypoxia enhances stimulus-dependent induction of E-selectin on aortic endothelial cells

In many diseases, tissue hypoxia occurs in conjunction with other inflammatory processes. Since previous studies have demonstrated a role for leukocytes in ischemia/reperfusion injury, we hypothesized that endothelial hypoxia may "superinduce" expression of an important leukocyte adhesion molecule, E-selectin (ELAM-1, CD62E). Bovine aortic endothelial monolayers were exposed to hypoxia in the presence or absence of tumor-necrosis factor alpha (TNF-alpha) or lipopolysaccharide (LPS). Cell surface E-selectin was quantitated by whole cell ELISA or by immunoprecipitation using polyclonal anti-E-selectin sera. Endothelial mRNA levels were assessed using ribonuclease protection assays. Hypoxia alone did not induce endothelial E-selectin expression. However, enhanced induction of E-selectin was observed with the combination of hypoxia and TNF-alpha (270% increase over normoxia and TNF-alpha) or hypoxia and LPS (190% increase over normoxia and LPS). These studies revealed that a mechanism for such enhancement may be hypoxia-elicited decrements in endothelial intracellular levels of cAMP (<50% compared with normoxia). Addition of forskolin and isobutyl-methyl-xanthine during hypoxia resulted in reversal of cAMP decreases and a loss of enhanced E-selectin surface expression with the combination of TNF-alpha and hypoxia. We conclude that endothelial hypoxia may provide a novel signal for superinduction of E-selectin during states of inflammation.

Interleukin-4 and interleukin-13 differentially regulate epithelial chloride secretion

Intestinal epithelia are in intimate contact with subepithelial and intraepithelial lymphocytes. When stimulated, mucosal lymphocytes generate cytokines that act locally and influence functional aspects of many cell types. We have previously defined functional epithelial receptors for interferon-gamma, interleukin (IL)-4, and a recently described IL-4-like cytokine IL-13. In this study, we examine the ion transport properties of T84 cells, a crypt-like epithelial cell line, following exposure to IL-4 and IL-13. Basolateral exposure of epithelial monolayers to both IL-4 and IL-13 attenuated epithelial barrier function and increased paracellular flux of a dextran marker by greater than 65% in a dose- and time-dependent fashion. Stimulated Cl- secretion, as measured by epithelial short circuit current, however, was diminished only by IL-4 and not IL-13, demonstrating cytokine specificity in this epithelial function. Decreased Cl- secretion following IL-4 exposure was associated with diminished Cl- channel activity and IL-4 pretreatment of epithelia decreased expression of the cystic fibrosis transmembrane regulator. Finally, stimulated fluid transport across cultured epithelia was diminished following exposure to IL-4, but not IL-13. These results indicate that while post-receptor signaling events induced by IL-13 and IL-4 may be similar, end point function is cytokine-specific.

[Retrospective analysis of early and late results following surgical intervention in supraventricular arrhythmia]

The results of surgical procedures for treatment of supraventricular tachycardias were assessed in 65 patients undergoing operation between January, 1980 and December, 1993. Indications for intervention were WPW (59 patients), atrial fibrillation (5 patients) and atrial flutter (1 patient). All cases of WPW were refractory to medical treatment and 14 of 58 patients had one or several syncopes, 4 of whom had to be resuscitated. The surgical treatment of these patients was dissection of an accessory atrioventricular pathway. 15 of these patients underwent heart operation for a different indication at the same time. A total of 60 accessory pathways were diagnosed preoperatively, while 4 were located intraoperatively. The reoperation rate was 3% (2 patients) due to persistent WPW. Incidence of total AV block after the operation was 7% (4 patients). In the late postoperative stage, 12 patients developed supraventricular tachycardias, but none of these cases required surgical treatment. The actuarial survival rate after 10 years was 100%, and after 14 years 96%. We conclude that surgical dissection of accessory pathways offers a good alternative in cases of unsuccessful catheter ablative procedures or in cases of concomitant heart surgery. In 6 patients with mitral valve surgery, associated chronic atrial fibrillation was found. A concomitant Maze-procedure was performed for the purpose of surgically converting the atrial fibrillation to a stable sinus rhythm. The early postoperative results are promising.

The internal mammary artery malperfusion syndrome: incidence, treatment and angiographic verification

Internal mammary artery (IMA) malperfusion syndrome is caused by an acute imbalance between myocardial demand and nutritional support through the mammary artery. In a consecutive series of 2326 isolated myocardial revascularizations-with at least one IMA to the left anterior descending branch (LAD) in 91.3% (2125/2326)-we identified 45 patients (1.9%) with a perioperative course suggesting IMA malperfusion syndrome. Additional saphenous vein graft to the distal segment of the LAD was performed during normothermic ventricular fibrillation in all patients. Hospital mortality was 4.4% (2/45), intra-aortic balloon pumping was required in 15.5% (7/45) and anterior myocardial infarction occurred in 28.8% (13/45). Coronary angiography was performed in all survivors between 3 and 24 months postoperatively. Wide patent IMA graft and patent saphenous vein graft were observed in 56% (24/43), narrowed but patent IMA graft and patent vein graft in 35% (15/43), while patent vein graft and not visualized IMA in 7% (3/43); in one patient with severely diseased peripheral LAD, no flow could be demonstrated in the IMA graft or in the additional vein graft (1/43, 2.4%). No major differences were found between early and late coronary angiography in these patients. Additional vein graft to distal LAD is the treatment of choice in acute IMA malperfusion syndrome. Despite patent vein graft with superior blood flow, early and late postoperative IMA flow to LAD is maintained in the majority of patients.

[Preventive digitalis therapy in open thoracotomy]

Prophylactic digitalization is still recommended after open lung surgery in order to prevent cardiac arrhythmias in the postoperative period. Since a beneficial effect of this potentially harmful medication is only poorly documented, we conducted a prospective randomized trial. Patients undergoing elective open lung surgery were divided into two groups one of which received digoxin postoperatively, the other not. Randomization was performed independently in three groups with regard to the extent of surgery, i.e. pneumonectomies in patients of any age, (bi-)lobectomies in patients > 50 and other (less extended) operations in patients > 60. Patients who were either too young for either group or who had already taken digoxin before surgery were followed separately. Monitoring was performed continuously in the ICU and conventional ECG was registered after 24, 48 and 72 hours and weekly until dismission.--Cardiac arrhythmias are very frequent in the early postoperative period with a maximum between the third and the fifth postoperative day. Any kind of arrhythmias were present in 19 of 30 patients (63%) compared to 14 of 35 patients (40%) in the control group. Symptomatic arrhythmias that needed treatment occurred in 11.4% of the control group, but in 33.3% of the patients with prophylactic digitalization. We therefore conclude that a general prophylactic digitalization after open lung surgery is not indicated, but that arrhythmias should be treated individually.

[Differential surgical therapy of popliteal entrapment syndrome 1967 to 1992]

From 1967 to 1992 at the University Hospital of Zurich 16 patients (14 male, 2 female) with 22 popliteal artery entrapment syndromes underwent a surgical treatment. In this period several different operation procedures were used. The modern operative procedure depends on the degree of the arteries wall compression. The procedure of choice for minimal compression of arterial wall is a musculo-tendinous decompression with a medial replacement of the popliteal artery. In the cases of severe compression we used autologous venous bypass from femoropopliteal I to popliteal III.

[Standardized follow-up after peripheral bypass operation]

We present a standard protocol of postoperative controls designed for early recognition of possible stenosis or graft failures after peripheral bypass operations. This protocol includes: a) angiography during the first week after surgery, b) clinical and Doppler-pressure measurement 1, 3, 6 and 12 months after surgery. 53 patients with 62 peripheral bypasses were followed. The cumulative patency rate was 87.5% after 12 months.

[Use of a semi-elastic synthetic cast in functional treatment of fresh injuries]

Functional treatment of injured joints is increasing since the introduction of semi-rigid plaster. Injuries to the ligaments of the ankle joint, ruptured Achilles tendon, but also other joints with injured ligaments are suitable for this therapy. We report about our experience of 120 treated ligamental injuries of the ankle joint, treated in a conservative way with semi-rigid plasters.

[Dynamic obstruction of the left ventricular outflow tract: surgical problems]

Dynamic subaortic obstruction caused by septal hypertrophy may worsen the hemodynamics in some patients after heart surgery. Resection of the hypertrophied septum allows normal left ventricular function. We describe two patients with subaortic stenosis and a complicated postoperative course following heart surgery and additional resection of the subaortic muscular stenosis. One patient was reoperated because of residual obstruction of the left ventricular outflow tract; the postoperative course was uneventful thereafter. The second patient died after the primary surgery because of low output syndrome and sepsis. The postoperative management of this group of patients is difficult, demanding frequent assessment of the patient's hemodynamic condition and echocardiographic surveillance.

Treatment of internal mammary artery malperfusion syndrome by additional venous graft: early postoperative angiographic results

BACKGROUND

Internal mammary artery malperfusion syndrome is caused by an acute imbalance between myocardial demand and nutritional support through the mammary artery.

METHODS

We performed early angiography in 11 consecutive patients in whom the perioperative course suggested mammary artery malperfusion. All patients received an additional saphenous vein graft distally to the mammary artery anastomosis.

RESULTS

Postoperative angiography revealed patent mammary artery and vein graft in 10 patients (three with a markedly reduced caliber of the arterial graft).

CONCLUSION

Additional vein graft is the treatment of choice in mammary artery malperfusion syndrome; it does not lead to occlusion of the internal mammary artery.

[Ectopic ossification as a cause of vague abdominal pain following heart surgery: a case report]

Vague abdominal pain after cardiac surgery was caused by ectopic ossification in the distal part of sternotomy. The rarity of this complication (one case seen in recent years, operation volume: 1200 cases/year) prompted us to review the literature, where only 6 cases are described. Diagnostic problems and therapy are discussed.

[Functional therapy of Achilles tendon rupture]

We are going to present two cases with functional treatment of Achilles tendon ruptures. We define a treatment as functional if the involved limb is either not immobilized at all or whenever the immobilization is incomplete and for a limited time only and when no operation is necessary. The functional treatment is presented as an alternative, and we are going to present the advantage and disadvantage.

[Indications, technique and interpretation of arterial Doppler ultrasound]

Doppler sonography is one of the most important diagnostic tools for angiologists and vascular surgeons, and also for general practitioners with an interest in vascular disease. It can be carried out easily and at low cost and at the same time provides reproducible, quantitative data on with further diagnostic and therapeutic decisions can be based. First, systolic arterial pressure in the anterior and posterior tibial and in the peroneal arteries are measured, with the Doppler probe placed at ankle level. A cuff is wrapped around the lower leg and inflated until the Doppler signal disappears and then deflated. The highest value measured in each leg is termed "ankle pressure". Division of the latter by systolic brachial pressure results in the so-called "ankle-brachial-index" or "ABI". Ankle pressure and ABI correlate well with clinical findings. In normal individuals, the ABI is greater than 1. In claudicators, it ranges between 0.3 and 0.9, in patients with resting pain between 0.1 and 0.5 and with ischemic tissue loss between 0.0 and 0.2. After angioplastic or surgical revascularisation procedures, a fall of the ABI by 0.15 or more is an indication of relevant hemodynamic deterioration and therefore calls for further investigation by arteriography or colour duplex sonography.

[Arterial popliteal entrapment syndrome as the cause of acute peripheral ischemia]

The popliteal artery entrapment syndrome results from an abnormal relation of artery and tendomuscular structures in the popliteal fossa, which can compromise the artery. We report our experience in 18 cases of popliteal artery entrapment syndrome in 14 patients (12 men, 2 women) operated on at the University Hospital in Zurich during the period 1967-1988. A follow-up examination was possible in 12 of the 14 patients in whom popliteal artery entrapment syndrome (both legs in 2) was treated surgically. These patients had first presented with ischaemic symptoms at an average age of 30 years. The correct diagnosis of an entrapment syndrome was made at an average age of 36 years. In all, 5 of the 14 patients were affected bilaterally. In 5 cases the first sign was an acute ischaemic syndrome. All these patients were young and had formerly taken active part in sport. The follow-up examination after an average age of 11.25 years showed a very good result in 13 cases, a good result in 2 cases and an unsatisfactory postoperative result in 1.

[Indications for, technique and interpretation of arterial Doppler sonography from the vascular surgeon's viewpoint]

Doppler sonography is one of the most important diagnostic tools for angiologists and vascular surgeons and also for general practitioners with an interest in vascular disease. It can be carried out easily and at low cost and, at the same time, provides reproducible, quantitative data on which further diagnostic and therapeutic decisions can be based. First, systolic arterial pressures in the anterior and posterior tibial and in the peroneal arteries are measured, with the Doppler probe placed at ankle level. A cuff is wrapped around the lower leg and inflated until the Doppler signal disappears. The highest value measured in each leg is termed ankle pressure. Division of the latter by systolic brachial pressure results in the so-called ankle-brachial index or "ABI". Ankle pressure and ABI correlate well with clinical findings. In normal individuals it is greater than 1. In claudication it ranges between 0.3 and 0.9, in patients with resting pain between 0.1 and 0.5 and with ischemic tissue loss between 0.0 and 0.2. After angioplastic or surgical revascularization procedures, a fall of the ABI by 0.15 or more is an indication of relevant hemodynamic deterioration and, therefore, calls for further investigation by arteriography or color duplex sonography.

Retroperitoneal malignant fibrous histiocytoma. Report of two cases

We present 2 cases of malignant fibrous histiocytoma (MFH) of the retroperitoneum. Only 12-14% of all MFH occur in the retroperitoneum. Both patients were operated with the diagnosis of a kidney tumor. The surgical exposure showed a tumor arising from the retroperitoneum, infiltrating or surrounding the kidney. We would like to emphasize that large tumors of the retroperitoneum which resemble kidney tumors can also arise from mesenchymal tissue.

[Bodybuilding: hypokalemia and hypophosphatemia]

In preparing for competitive body building, body builders--in addition to continuous and hard muscle training--engage in stringent dietetic manipulations: the first few months of hypercaloric nutrition, rich in proteins, are devoted to the build-up of muscle mass. A second phase of reduced caloric intake is designed reduce subcutaneous fat, while, during the last week of preparations, extreme carbohydrate intake aims at loading muscles with glycogen. Simultaneously, sodium and water restriction results in extracellular and therefore subcutaneous volume deficit and better "definition" of muscle contours and structure. In the course of these dietetic manipulations a young body builder develops hypokalemia, hypophosphatemia, rhabdomyolysis and flaccid tetraparesis. The disturbances are pathophysiologically predictable.