[Intraoperative findings and postoperative computer tomographic follow up of inflammatory aortic aneurysm]

PURPOSE

Retrospective evaluation of postoperative long-term results after surgery of inflammatory aortic aneurysms (IAAA) with computed tomography (CT). Findings in CT were analysed with particular attention to the development of inflammatory tissue adjacent to the aneurysm site.

MATERIAL AND METHODS

Of 2101 patients operated on an aortic aneurysm 5.4% (114 patients) presented typical intraoperative features of inflammatory aortic aneurysms. 54 of these 114 patients (47%) were examined via computed tomography pre- and post-operatively. On an average the follow-up-study was performed 2.5 years postoperatively.

RESULTS

All follow-up-studies revealed a correct location of the aortic prostheses. In 85.1% of the cases there was either no or negligible persisting inflammatory tissue with a diameter of less than 2 mm. 10.6% of the patients demonstrated remaining but reduced inflammatory tissue. In 4.3% of the cases the extent of the inflammatory tissue had not changed. Aneurysms of the anastomoses (n = 4), morphologic renal changes (n = 7) and an aorto-enteric fistula were demonstrated by CT as postoperative complications.

CONCLUSIONS

In evaluating recurrence of the aneurysm and possible complications as well as the development of the inflammatory tissue, postoperatively performed computed tomography proved a reliable diagnostic method.

Pseudo- and segmental occlusion of the internal carotid artery: a new classification, surgical treatment and results

OBJECTIVES

Occluded internal carotid arteries imply a high risk of ischaemic complications, but an "occluded" carotid artery is not always totally occluded. Pseudo- and segmental occlusions can be detected angiographically, and increasingly non-invasively, and include a variety of morphologic findings.

METHODS AND MATERIALS

128 patients with pseudo- or segmental occlusion were treated in a 13 year period. Three different types of pseudo- or segmental occlusion were identified. In most cases a subtotal stenosis (near-occlusion) at the carotid bifurcation is the underlying lesion (type I). In approximately 35% the internal carotid artery is totally occluded at the bifurcation, but collaterals prevent downstream occlusion (type II), or retrograde flow from the circle of Willis and ophthalmic artery preserves a patent petrous part and siphon (type III).

RESULTS

In 79% patency of the arteries could be restored. Three patients (2.3%) died perioperatively, nine (7%) developed ischaemic stroke (7 ipsilateral, 2 contralateral), one intracerebral haemorrhage. The combined stroke-mortality rate was 8.6%. During follow-up (41 +/- 29.9 months) four patients (4.5%) experienced a stroke (3 ipsilateral, 1 contralateral), one an intracranial (1.1%) haemorrhage and six transient ischaemic attacks (6.7%). The annual ipsilateral stroke rate was 0.9%, the cumulative patency rate of the entire series 78% after 73 months.

CONCLUSIONS

Although the surgical management carries an increased risk of complications (stroke, transient ischaemic attacks) compared to conventional carotid endarterectomy it is likely that the stroke risk can be reduced at least for symptomatic patients. Symptomatic internal carotid artery occlusion diagnosed non-invasively should be confirmed angiographically to exclude pseudo- or segmental occlusion.

[Surgical treatment of deep venous thrombosis--indications, possibilities and limitations in venous thrombectomy]

Venous thrombectomy as a treatment of deep venous thrombosis is discussed extremely controversial. Occasionally, however, surgical technique, goal of the therapy, indications and limitations are not really known. Indication for surgical treatment is an extensive acute deep vein thrombosis with clinical symptoms of less than 7 days. Goal of the therapy is the preservation of valve function and prevention of a postphlebitic syndrome. Further indications are an embolizing venous thrombosis, a floating thrombus and an ischemic thrombosis. In these cases the single goal of the treatment is to reduce the individual risk of the patient. The best long term results can be achieved in young patients (below 40 years of age) with no preexisting venous lesion and an acute iliofemoral thrombosis. Advantages, drawbacks and results of venous thrombectomy are discussed.

Color-flow Doppler-assisted duplex imaging fails to detect ulceration in high-grade internal carotid artery stenosis

PURPOSE

Pathoanatomic studies suggest that plaque surface disruption, particularly ulceration, plays a key role in the destabilization of internal carotid artery stenosis. Until now, the validity of color-flow Doppler-assisted duplex imaging in detecting such pathoanatomically defined plaque surface abnormalities is unclear.

METHODS

We prospectively determined the interobserver reliability and validity of detecting plaque ulceration by means of preoperative color-flow Doppler-assisted duplex imaging in 43 consecutive patients with high-grade (> or = 70%) internal carotid artery stenosis, comparing these ultrasonographic findings with pathoanatomic evaluations of the corresponding endarterectomy specimens.

RESULTS

Interobserver reliabilities for detecting carotid plaque ulceration were kappa= 0.57 for ultrasonography and kappa = 0.82 for the pathologic reference method. Color-flow Doppler-assisted duplex imaging (observer consensus) failed to detect pathoanatomically defined ulceration (chi square = 0.43; p = 0.51). Likewise, sensitivity, specificity, overall accuracy, and positive predictive value were poor (33%, 67%, 56%, and 46%, respectively).

CONCLUSIONS

We conclude from our data that color-flow Doppler-assisted duplex imaging is not a reliable or valid means to identify plaque ulceration in high-grade carotid artery lesions.

[Infection of a vascular prosthesis--a retrospective analysis of 99 cases]

From January 1, 1980 to December 31, 1992, 7970 vascular prostheses have been implanted at the Department for Vascular Surgery and Kidney Transplantation of the University of Düsseldorf. In the same period of time, 99 patients had to be reoperated for (type Szilagyi III [14]) graft infection (1,2%), out of which 70 patients have had their previous operation in our institution (0,9%). The infection became apparent within 30 days in 14 cases, within one year in 54 cases, and in 31 cases within a maximum of 8 years postoperatively. Localisation of the infection was the groin in 70 patients, abdominal aortic prostheses were involved in 16, crural or extraanatomic prostheses in 13 cases. Treatment consisted in most cases of axillofemoral bypass (n = 23) and obturator-bypass (n = 21). In-situ-implantation of vascular prostheses was performed in 8 cases, 4 of these prostheses were intraoperatively soaked with an antibiotic. 47 patients had various reconstructions, such as cross-over bypasses, atypical reconstructions or local treatment. Postoperatively 27 amputations were necessary. 30-days mortality rate was 12%. At the end of the follow-up (May 1994) we found a 54% total mortality rate (mean follow-up: 4.6 +/- 4.59 years). Main cause of death in the first year was sepsis. In only 67% of patients discharged from hospital, the peripheral arterial conditions were described as "good" by angiography, ankle-brachial index or clinical examination. We conclude, that vascular graft sepsis threatens the patient in the early phase because of limb loss or death, and during the first year after the operation for the sequelae of sepsis or recurrence. Revascularisation with antibiotic-soaked grafts in a limited number of cases showed good results in preserving limbs and lives of our patients. Future experience will show, whether antibiotic-soaked grafts should be used more generously in vascular surgery.

Heparin as a cause of thrombus progression. Heparin-associated thrombocytopenia is an important differential diagnosis in paediatric patients even with normal platelet counts

A 15-year-old boy developed deep vein thrombosis of the right leg 9 days after appendectomy. In spite of three courses of thrombolysis with streptokinase and effective heparinization the thrombosis progressed with additional occlusion of the left iliac vein. Although platelet counts were constantly normal, heparin-associated thrombocytopenia was suspected as the cause of the new venous occlusions. This diagnosis was confirmed by detecting heparin-associated antibodies with the heparin-induced platelet activation test. Therapy was instituted replacing heparin by the low molecular weight heparinoid Orgaran. Bilateral recanalization occurred within 6 days.

CONCLUSION

Heparin-associated thrombocytopenia must be considered if thrombosis occurs or progresses despite effective heparinization even in the absence of thrombocytopenia.

[Surgical treatment of thoraco-abdominal aneurysm. Indications and results]

Aortic replacement for thoraco-abdominal aneurysms remains a major challenge in vascular surgery. Related symptoms, maximal diameter > 6 cm, progression, aneurysm sac containing none or excentric thrombi and uncontrollable hypertension are factors in favour of surgery, if the general condition of the patient allows the operation. Patients with aneurysms < 5 cm maximal diameter, tube-size aneurysms, heavy calcification of the aortic wall, concentric thrombi within the aneurysmal sac and significant cardiopulmonary risks should be treated conservatively. Patients in good general condition with aneurysms around 5 cm maximal diameter should be controlled by computed tomography in 6 to 12 months intervals and in the case of progression surgery can be recommended despite missing symptoms. Crawford developed the 'graft-inclusion-technique', which combines the 'ingraft'-technique with reattachment of renal, visceral and segmental arteries. The 'clamp and repair' principle is used in patients with sufficient cardiac function. Otherwise shunt or left sided heart bypass are used to reduce cardiac afterload. According to the literature local cooling (flush perfusion), cytoprotective drugs and numerous methods to maintain or ameliorate distal aortic perfusion during clamping ischemia have been used in patients successfully for prevention of ischemic spinal complications. In physiological settings these methods may prove valuable, but under pathophysiological conditions of TAAA-repair one must doubt the efficacy, because the individual risk is difficult to assess. In our hands flush perfusion and cooling of the kidneys proved to be helpful. In animal experiments we have shown prolongation of ischemia tolerance time using eicosanoides to protect the kidneys and the spinal cord. If shunt or left-sided heart bypass can protect the spinal cord during clamping, is unknown, because the risk of paraplegia in the individual patient can be known only, if the function of the spinal cord is monitored. We have developed a spinal neuromonitoring system and found, that only one third of all TAAA-patients is at high risk to develop paraplegia during aortic clamping. The surgeon is guided by continuous recording of spinal evoked somatosensory potentials and can adapt the operative technique by early reimplantation and eventually subsequent separate reimplantation of segmental arteries supplying blood to the spinal cord, in order to reduce spinal ischemia time. Our results in 260 TAAA-patients are presented. In a high-risk population of patients with aneurysms type I-III (Crawford's classification) it was possible, to reduce the paraplegia rate from 7 to 3.5%, the risk of paraparesis from 15 to 6%, while the operative mortality was only reduced from 19 to 10%.

Surgical treatment of septic deep venous thrombosis

BACKGROUND

Septic deep venous thrombosis (SDVT) is an uncommon but occasionally lethal disease caused by systemic complications. In most cases reported in the literature SDVT is caused by intravenous drug abuse or transvenous catheter lines. Conservative management with antibiotic drugs and systemic anticoagulation is usually successful, and the surgical approach is regarded as not indicated or unnecessary. Occasionally, however, conservative management fails, thrombosis progresses, and septic embolism develops.

METHODS

In a 7-year period five patients (three male and two female; mean age, 21.2 years), three with severe systemic complications of SDVT (femoropopliteal, 1; iliofemoral, 1; iliofemoral+vena cava, 3), were treated by venous thrombectomy in addition to intravenous antibiotic administration. Simultaneous transabdominal caval thrombectomy was performed twice.

RESULTS

Two patients suffered from respiratory failure caused by previous septic embolization. One patient had experienced multiorgan failure before thrombectomy was performed. Intensive care was necessary for all patients (mean, 28 days). All patients survived.

CONCLUSIONS

In complicated cases of SDVT without improvement or even impairment after conservative management, venous thrombectomy is a lifesaving treatment.

Plaque ulceration and lumen thrombus are the main sources of cerebral microemboli in high-grade internal carotid artery stenosis

BACKGROUND AND PURPOSE

Previous work has shown that rates of cerebral microemboli downstream of high-grade internal carotid artery stenosis are higher in recently symptomatic compared with asymptomatic patients. In addition, microembolic rates decline after carotid endarterectomy. We conducted a prospective investigation of 40 consecutive asymptomatic or recently symptomatic patients undergoing carotid endarterectomy for 70% to 95% internal carotid artery stenosis to determine the relationship between microembolic rate and pathoanatomic features of the carotid plaque.

METHODS

Transcranial Doppler monitoring including automated emboli detection was performed preoperatively to assess the rate of cerebral microemboli of the ipsilateral middle cerebral artery. The corresponding endarterectomy specimens were evaluated histologically with respect to the occurrence of plaque fissuring, intraplaque hemorrhage, plaque ulceration, or intraluminal thrombosis.

RESULTS

There were strong associations between plaque ulceration, intraluminal thrombosis, and downstream cerebral microemboli (P < or = .005, respectively). There were no correlations of microembolism with plaque fissuring or intraplaque hemorrhage (P = .82 and P = .28, respectively).

CONCLUSIONS

We conclude that ulceration and luminal thrombosis of the atheromatous plaque are the main sources of downstream cerebral microemboli in patients with high-grade internal carotid artery stenosis. Our data support the view that these pathoanatomic features may also play a key role in symptom development.

The effects of prostacyclin on gastric intramucosal pH in patients with septic shock

OBJECTIVE

To investigate whether infusing prostacyclin (PGI2) in patients with septic shock improves splanchnic oxygenation as assessed by gastric intramucosal pH (pHi).

DESIGN

Interventional clinical study.

SETTING

Surgical ICU in a university hospital.

PATIENTS

16 consecutive patients with septic shock according to the criteria of the ACCP/SCCM consensus conference all requiring norepinephrine to maintain arterial blood pressure.

INTERVENTIONS

All patients received PGI2 (10 ng/kg x min) after no further increase in oxygen delivery could be obtained by volume expansion, red cell transfusion and dobutamine infusion. The results were compared with those before and after conventional resuscitation. The patients received continuous PGI2 infusion for 33-32 days.

MEASUREMENTS AND RESULTS

O2 uptake was measured directly in the respiratory gases, pHi was determined by tonometry. Baseline O2 delivery, O2 uptake and pHi were 466 +/- 122 ml/min.m2, 158 +/- 38 ml/min.m2, and 7.29 +/- 0.09, respectively. While O2 uptake remained unchanged, infusing PGI2 increased O2 delivery (from 610 +/- 140 to 682 +/- 155 ml/min.m2, p < 0.01) and pHi (from 7.32 +/- 0.09 to 7.38 +/- 0.08, p < 0.001) beyond the values obtained by conventional resuscitation. While 9 of 11 patients with final pHi > 7.35 survived, all patients with final pHi < 7.35 died (p < 0.01).

CONCLUSIONS

Infusing PGI2 in patients with septic shock increases pHi probably by enhancing blood flow to the splanchnic bed and thereby improves splanchnic oxygenation even when conventional resuscitation goals have been achieved.

Complications following caval interruption

Caval interruption is widely regarded as the treatment of choice for the prevention of recurrent pulmonary embolism (PE). The safety, ease of insertion and "convenience" of the devices are the main arguments for filter placement. Today many filters are placed for prophylactic reasons, sometimes without an established diagnosis of pulmonary embolism or underlying deep venous thrombosis. Early and late complications have been published but the rate is reported to be low, although only limited numbers of patients have been followed. In an 18-year period 11 patients with problems following caval interruption were treated, 10 with acute complications, one with chronic caval occlusion. Six were treated conservatively, five underwent venous thrombectomy and a.v.-fistula. The device was removed in four. During the same period only three permanent filters were placed in our hospital (two with complications). Caval interruption is useful in selected high-risk patients and is the least invasive but not necessarily the best treatment. Provided stringent criteria are applied, the early and late complications can be accepted in order to prevent sudden death in patients with threatening massive PE. Extended or more liberal indications for caval interruption are neither necessary nor justified.

[Chronic mesenteric ischemia]

Thirty-four patients (twelve men, 22 women, mean age 53[16-71] years) with chronic mesenteric ischaemia were operated upon between 1979 and 1992. The most frequent symptom was loss of weight (50%) and postprandial pain (44%). The mean interval between onset of symptoms and diagnosis was 35 months. Angiography revealed disease of the coeliac trunk (CT) or the superior mesenteric artery (SMA) in 16 patients, of only the SMA in ten, and of only the CT in eight. Revascularisation was obtained with an autologous vein graft in 21 patients (on the TC in 12, AMS in nine), while transaortic endarterectomy was performed in 15 (on the CT in seven, the AMS in nine). There was one perioperative death. 20 patients were symptom-free 1-126 months after the operation, while five still had residual symptoms even though improved in three. Seven patients had a recurrence of symptoms, three immediately after operation and four after an initial symptom-free period. These results show that freedom from symptoms can be achieved even in advanced stages of chronic mesenteric ischaemia by reconstructive surgery of the intestinal and visceral arteries. However, residual symptoms that are possibly not of a vascular nature may persist after successful vascular reconstruction. Patients with recurrent obstruction may become symptom-free by repeat surgery even many years later.

[The computed tomographic diagnosis of inflammatory abdominal aortic aneurysms]

Amongst 1599 patients undergoing surgery for abdominal aortic aneurysm, there were 89 patients (5.6%) who showed typical features of inflammatory aneurysms of the abdominal aorta (IAAA). 37 of the 89 patients had been examined preoperatively by CT. In 73% of the cases (27/37) a correct diagnosis had been made. Localisation, width and extent of the IAAA was correctly diagnosed in all patients. Involvement of the renal arteries by the inflammatory process, the extent of thrombus and of mural calcification were accurately shown. The inflammatory tissues were typically ventral and lateral to the aorta. Frequently, there were adhesions to neighbouring structures. Aortic rupture, aortic dissection and retroperitoneal lymphoma may produce similar CT appearances; nevertheless, CT remains at present the method of choice for the diagnosis of IAAA because of its high sensitivity.

[The spectrum of the findings of arterial digital subtraction angiography in patients following kidney transplantation]

Digital subtraction angiography (DSA) was performed in 53 of 417 patients with renal transplants. The incidence of clinical apparent vascular complications was 9.1% of all patients with renal transplants (38/417). The most frequent vascular disorders were formed by arterial stenoses at 5.0% of the cases followed by arterial obstructions in 1.7% of the patients. Rare vascular complications were arteriovenous fistulas (0.7%), aneurysms (0.5%) and venous thromboses (0.2%). Because of the high diagnostic value of intraarterial DSA, all patients with renal transplants with a complicated postoperative course should be eligible for angiographic control. In case of a suspected vascular disorder intraarterial DSA should be performed at an early stage.

Thrombectomy with arteriovenous fistula for embolizing deep venous thrombosis: an alternative therapy for prevention of recurrent pulmonary embolism

Thrombectomy with arteriovenous fistula was performed between 1977 and 1988 in 103 patients (41 females, 62 males, mean age 46.7 years, 114 involved extremities) with embolizing deep-vein thrombosis (DVT). The sole aim of the surgical procedure was prevention of recurrent embolization. On the basis of the proximal extent of the thrombosis the source of embolization was identified as the iliac veins or inferior vena cava in 63% of the patients; 48% presented with a post-phlebitic vein and/or an older thrombosis, and 46% had already had recurrent pulmonary emboli. Unsuccessful aggressive procedures had been carried out previously in 11%. The rate of intraoperative pulmonary embolism (PE) was 3% (one fatal case). The perioperative mortality was 6.8%, but only one death was related to the surgical treatment itself. During follow-up (8-140 months postoperatively, mean 55 +/- 34 months) late recurrent PE was confirmed in two patients (antithrombin III deficiency, contralateral DVT) and was reported as the suspected cause of death in a third (3.6%). Venous thrombectomy with arteriovenous fistula is a reliable and effective procedure for management of embolizing DVT and is indicated especially in young patients. The rates of early- and late-recurrent PE are low, introduction of artificial material into the vein can be avoided, and long-term preservation of valve function is occasionally possible.

Extended deep vein and inferior vena cava thrombosis in a 15-year-old boy: successful lysis with recombinant tissue-type plasminogen activator 2 weeks after onset of symptoms

We present the case of a 15-year-old boy with thrombosis of the inferior vena cava, the femoral, inguinal, and renal veins of unknown origin. Although the thrombosis was 2 weeks old, thrombolytic therapy with recombinant tissue-type plasminogen activator (maximum dosage: 0.4 mg/kg/h) was started as this appeared to be the only change to re-establish normal kidney function. After 1 week, treatment was discontinued because of generalized bleeding. At this time, the infrarenal inferior vena cava was again patent with complete lysis of all other clots. Phlebography 3 months after lysis documented an abnormal renal vein, a tubular, subhepatical stenosis of the inferior vena cava and a large collateral vessel between the inferior vena cava and the azygos vein.

In situ and composite in situ vein bypass for upper extremity ischaemia

The in situ saphenous vein bypass for lower limb revascularisation is well established. For upper extremity ischaemia necessitating bypass this special technique offers the same advantages. From 1987 to 1991 five patients underwent cephalic and basilic vein in situ bypass for critical ischaemia of the upper extremity. Underlying disease was a thoracic outlet syndrome (two cases), radiation injury (one case) and a chronic atherosclerotic lesion (two cases). One graft failed because of a critical outflow situation. The most important advantage of the in situ technique for revascularisation of the upper extremity seems to be minimal endothelial damage and the better compliance of the in situ vein to the extensive movements of the joints.

[Surgical therapy of acute and embolizing deep venous thrombosis--indication, technical principle, results]

Between 1977 and 1986, 185 patients with deep venous thrombosis (117 with acute occlusive and 68 with embolizing deep venous thrombosis) underwent venous thrombectomy with arterio-venous fistula. The early patency rate was 96%, and the perioperative mortality rate, 3.8%. Of the 157 patients in whom extremities were involved, 147 were examined 12-118 months postoperatively (mean 43 +/- 23 months) clinically, by Doppler ultrasound and by light reflexion rheography (LRR). In 49% of the patients, various kinds of swelling or oedema of the involved extremities were present. There were no hemodynamical disturbances in 53% (LRR-examination); competent venous valves were found in 44%. According to the severity of symptoms and hemodynamical findings, postthrombotic syndrome was absent in 47%, mild in 20%, moderate in 28%, and severe in 5% (7 patients, 4 with venous ulcers). Six of the 7 patients with severe postthrombotic syndrome belonged to the group operated for embolizing thrombosis, where no selection of cases was performed. The best long-term results were achieved in patients operated for acute occlusive thrombosis of the iliac and iliofemoral veins. Venous thrombectomy with av fistula can achieve sufficient early and long-term results in the treatment of deep venous thrombosis, provided strict selection of patients and a meticulous technique are practised.

["Inflammatory aneurysm" of the aorta. Diagnosis, therapy, results]

From 1970 to 1987 among 964 patients with aortic aneurysms 52 (5.4%) underwent aortic graft replacement for inflammatory aortic aneurysm. 79.2% were symptomatic, 18.9% ruptured at the time of admission. CT-scan is of main diagnostic value. The perioperative mortality rate was 15.1%. At follow-up (28 months mean) 35 of 38 living patients (92.7%) were examined clinically, by sonography and in most cases by CT-scan. The late complication rate was 20% (n = 7, atrophic kidney 3, anastomotic aneurysms 4). In contrast to abdominal aortic aneurysms inflammatory aneurysms present an elevated morbidity and mortality rate which has to be reduced by exact preoperative diagnosis and modified surgical technique.