Aortic graft infections: treatment with arterial allograft.

Since its reintroduction by Kieffer in 1991, many authors have used arterial allografts for surgical management of vascular prosthetic graft infection. During a decade, 25 patients with aortic graft infection were treated using in situ revascularization with arterial allograft. There were 23 male and 2 female patients of mean age of 65.7 +/- 8.8 years (range, 43-78). Antibiotic therapy was administered for a mean time of 26 +/- 5 days (range, 21-45) in the postoperative period. The mean follow-up time was 2.3 +/- 3 years (range, 22 days-8.7 years). The mean in-hospital postoperative stay was 29.6 +/- 14 days (range, 9-68). An aorto-enteric fistula (AEF) was present in 11 patients (44%), producing gastrointestinal bleeding. The overall mortality rate was 13 of 23 (56.5%) patients. The allograft-related mortality rate was 5 of 23 (22%). The overall allograft-complicated patient rate was 15 of 23 (65%); we observed 18 allograft ruptures in 12 patients and 8 allograft thromboses in 6 patients. The overall amputation rate was 8.7% (2 of 23). Age of the recipient older than 69 years (P = .02), positive preoperative marked-leukocyte scanning (P = .04), and persistent postoperative leukocytosis (P = .03) were significant variables associated with an increased risk of allograft-related complications. The use of arterial allografts for aortic graft infections represents an interesting alternative for the treatment of graft infection. Nevertheless, there are some problems related to the durability of this type of graft, which can still be considered as a "bridge transplant."

Vascular prosthetic graft infection: epidemiology, bacteriology, pathogenesis and treatment.

UNLABELLED: Vascular prosthetic graft infection remains a major surgical challenge. Prevention of risk factors and antibiotic therapy can reduced but not eradicate it. Management of infected vascular grafts depends on several factors, including the location of the infected prosthesis, the extent of infection, and the underlying micro-organism. Classic treatment consists of extra-anatomic bypass grafting. The disappointing results due to the high mortality and amputation rate have kindled interest in alternative approaches, such as in situ reconstruction with antibiotic-bonded prostheses, autogenous veins or arterial allografts. PURPOSE: We focused on the treatment of aortic graft infection by means of both fresh and cryopreserved arterial allograft. Here, the experience of the Italian Collaborative Vascular Homograft Group is reported. METHODS: Between March 1994 and December 2000 seventy-nine patients with aortic graft infection were treated. The results of 68 patients are analysed. Eleven patients were treated with fresh, and 57 with cryopreserved homograft. Emergency surgical procedures were performed in 12 patients (17%). Aortoenteric fistula was diagnosed in 22 patients. The mean interval between the first procedure and the insertion of a homograft for patients with infected aortic graft was 3 years (range 1-15). The mean duration of follow-up was 30 months (range 1-68). Clinical and duplex scanning evaluation were routinely performed. Computer tomography (CT), magnetic resonance (MR), or arteriography were performed on the basis of duplex scanning results. RESULTS: The analysis was performed on 68 cases for which there were sufficient reliable data. Eleven deaths occurred during the early postoperative period (30 days), a mortality rate of 16%. There were also seventeen late deaths, a mortality rate of 25%. Eleven patients had graft occlusion; six cases were successfully treated with thrombectomy. In three cases leg amputation was necessary. The results of fresh and cryopreserved homografts were compared. No significant differences of early postoperative mortality, late mortality, homograft-related mortality, graft failure were observed. The presence of aortoenteric fistula is a negative predicting factor of perioperative early mortality, which causes a rapid decline in the survival curve. Thirty-six months after the surgery the actuarial survival of the patients was 57% and the actuarial patency of the allograft was 41%. CONCLUSION: No significant difference in terms of clinical outcome was observed when using fresh, rather than cryopreserved homografts. The only factor that significantly influenced the survival rate appeared to be the aorto-enteric fistula.

[Giant aneurysm of the renal artery. Case report]. / Aneurisma gigante dell'arteria renale. Caso clinico.

A case of a giant aneurysm of the right renal artery is described. A female patient, 65 years old, normotensive, affected by a great aneurysm of 7 cm per 6 cm, localized in the renal ilus and determining a chronical pyeloneprosis is observed. She was operated on for nephrectomy because the aneurysm and the kidney were strictly closed. The patient recovered her health. The current status of the art is then analysed.

[Indications for the use of vascular homografts]. / Indicazioni all'impiego degli omoinnesti vascolari.

Homografts were first mentioned in scientific literature at the beginning of the 1900s in articles by Yamanouchi and Carrel who were the first to demonstrate the possibility of substituting segments of artery by transplanted homologous segments of vein. Since then homografts have been considered a possible surgical treatment for stenotic and aneurysmal diseases of the aortic-iliac-femoral vasculature. Meanwhile much research has been carried out in an attempt to perfect the treatment that the biological prothesis undergoes once explanted. This treatment is aimed at providing the best possible conservation of the biological and mechanical characteristics of the graft while eliminating the highly antigenic components. The introduction in the 1950s of synthetic prostheses and their immediately encouraging short-term and long-term results, clearly better than those of the homografts, led to the use of these latter being temporarily abandoned. They came back into the spotlight some years later with completely different indications from those for which they had originally been proposed. The natural resistance to bacterial colonization makes the homograft an ideal candidate for treatment of infected prostheses or of patients at high risk of infection (immunosuppressed patients). Furthermore the low thrombogenicity and the case with which they can be sutured are important advantages for use in pediatric heart surgery and oncologic surgery in the treatment of associated vascular lesions. Nevertheless, large scale use of homografts cannot be recommended for a variety of reasons: 1) the need for ministerial authority; 2) the need for a tissue bank where the certification and cryopreservation of the homografts could be carried out; 3) the still unsettled doubts about immunological aspects associated with homografts.

Endovascular treatment of acute haemoptysis secondary to aortobronchial fistula.

INTRODUCTION: Aortobronchial fistula is a rare but potentially fatal condition. We report our experience in the endovascular treatment of acute haemoptysis in high risk patients with aortobronchial fistula. REPORT: Between May 2002 and December 2004 five patients presenting with acute haemoptysys due to aortobronchial fistula were treated by endovascular stent grafting of the descending thoracic aorta. We did not observe intraoperative or perioperative mortality, stent-graft infection or paraplegia. In one case endoleak occurred. CONCLUSION: Endovascular stent-grafting represents an effective therapeutic option for the management of aortobronchial fistula. Careful follow up of the patients is mandatory.

Near infrared spectroscopy monitoring during carotid endarterectomy: which threshold value is critical?

OBJECTIVES: Retrospectively to verify which decreasing percentage in regional oxygen saturation (rSO(2)) identified patients with good collateralisation during carotid artery cross clamp. MATERIALS AND METHODS: During 594 endarterectomies under general anaesthesia the decreasing percentage from preclamp value to value detected in the first 2 min after clamping the CCA and/or ICA was calculated in real time. No temporary shunt was placed in any case. ROC analysis was performed to determine the optimal cut-off for rSO(2) decrease to identify the occurrence of neurological complications. RESULTS: A cut-off of 11.7% was identified as optimal. Sensitivity and specificity were 75% (95% CI 71-78) and 77% (95% CI 74-80), respectively. The cut-off of 20% had a lower sensitivity (30%) and a higher specificity (98%) to identify patients with complications, with positive and negative predictive value of 37 and 98%, respectively. CONCLUSIONS: The study suggest that a relative decrease in rSO(2) of <20% from preclamp to early cross clamp value has a high negative predictive value, i.e. if rSO(2) does non decrease more than 20%, ischemia by hypoperfusion is unlikely and a shunt should not be necessary. Moreover, a relative decrease >20% may not always indicate intraoperative neurological complications.

A rapid D-dimer assay in patients presenting at the emergency room with suspected acute venous thrombosis: accuracy and relation to clinical variables.

BACKGROUND AND OBJECTIVES: The measurement of D-dimer is claimed to have potential value in excluding deep vein thrombosis (DVT). New rapid methods have been proposed, but few clinical trials have assessed their performance in an emergency context. The different accuracies found between the D-dimer assays have been related to the test used (latex or ELISA), but other variables (such as population investigated, thrombus extension, duration of symptoms or concomitant heparin treatment) may be important, even if not sufficiently investigated. DESIGN AND METHODS: We evaluated the accuracy of a rapid semi-quantitative D-dimer test (Dimertest, Dade Behring), with reference to: a) its use at an emergency unit; b) concomitant heparin administration; c) location of venous thrombosis (VT) (in the deep or superficial venous system limited to the great saphenous vein) and d) symptoms older than 14 days. RESULTS: Two hundred and ninety-eight patients suspected of having DVT and 116 suspected of thrombosis of the great saphenous vein (GSV) were investigated. In the DVT patients, the sensitivity, specificity, positive and negative predictive values were 77.4% (95% CI 68.9-85.9), 81.4% (95% CI 76.1-86.7), 65.4% (95% CI 56.5-74.3) and 88.8% (95% CI 84.2-93.4), respectively. Excluding patients receiving heparin and those with symptoms older than 15 days, the sensitivity and negative predictive value increased to 86.3% (95% CI 78.4-94.2) and 92.8% (95% CI 88.4-97.2), respectively. In patients with GSV thrombosis, the sensitivity, specificity, positive and negative predictive values were 48% (95% CI 34.5-61.5), 90.6% (95% CI 83.2-97.9), 80.6% (95% CI 66.6-94.6) and 68.2% (95% CI 57.8-78.6), respectively. Excluding patients receiving heparin and those with symptoms older than 15 days, did not change the sensitivity or negative predictive value significantly. INTERPRETATION AND CONCLUSIONS: Our results show that previous or concomitant heparin administration, non-acute symptoms and thrombosis localized to superficial veins reduce the clinical usefulness of the D-dimer test as the rate of false negative results is increased.

Fresh and cryopreserved arterial homografts in the treatment of prosthetic graft infections: experience of the Italian Collaborative Vascular Homograft Group.

Following the experience of cardiac surgeons with homografts in the treatment of infective aortic valve endocarditis, cardiovascular surgeons have investigated in situ revascularization by means of homografts in the management of vascular prosthetic graft infections. Preliminary results are encouraging, but their late fate in long-term follow-up and the influence of preservation techniques are still under investigation. This article reports the experience of the Italian Collaborative Vascular Homograft Group, with the use of fresh and cryopreserved arterial homografts for the treatment of prosthetic graft infections. Between March 1994 and December 1996, 44 patients with prosthetic graft infection were treated with homografts (13 preserved at 4 degrees C, 31 cryopreserved). The mean age of the patients was 65 years. Emergency surgical procedures were performed in eight patients (18%). Sepsis was diagnosed in 11 patients, aortoenteric fistula in 13, and false aneurysms in 10. Staphylococcus was the main cause of infection. The types of vascular reconstruction with homograft were: 32 aortobifemoral, 3 aortoaortic, 2 iliofemoral, 4 peripheral, and 3 axillobifemoral. Human lymphocyte antigen (HLA) and antibody (ABO) blood group system compatibility between donors and recipients was not respected. The mean duration of follow-up was 15 months (range 1-33). Clinical and duplex scanning evaluations were routinely performed. Computed tomography (CT) or magnetic resonance (MR) scanning or arteriography were performed on the basis of duplex scanning results. There were six deaths during the early postoperative period (30 days) with a mortality rate of 13.6%. During the follow-up there were five late deaths with a mortality rate of 11.4%. Eight patients had graft occlusion. Three cases were successfully treated with thrombectomy. Two cases were successfully treated with femoropopliteal bypass with autologous vein. In three cases leg amputation was necessary. The results of fresh and cryopreserved homograft were compared. No significative differences of early postoperative mortality, late mortality, homograft related mortality, and graft occlusion were observed. We have evaluated the actuarial survival of the patients and the actuarial patency of the homografts on the aortoiliac reconstructions. Twelve months after the surgery the actuarial survival of the patients was 73% and the actuarial patency of the homografts was 56%. In our preliminary experience, we have not observed any significant difference in terms of clinical outcome by using fresh rather than cryopreserved homografts. In the near future it will be our policy to employ only cryopreserved homografts. Moreover, we will extend vessel harvesting to nonheart-beating donors, thus maximizing retrieval. The aforementioned solutions will supply the best graft availability to obtain dimensional and ABO compatibility between donors and recipients.