Endotoxin related early neutrophil activation is associated with outcome after thoracoabdominal aortic aneurysm repair

BACKGROUND

Thoracoabdominal aortic aneurysm (TAAA) repair is associated with high mortality rates, especially in patients who develop postoperative renal and pulmonary impairment. Organ damage during TAAA repair may be mediated by activated polymorphonuclear neutrophils (PMNs) during a systemic inflammatory response. The association between intraoperative neutrophil activation and postoperative outcome was studied after TAAA surgery.

METHODS

Perioperative PMN activation (surface CD11b expression by flow cytometry), plasma endotoxin, plasma endotoxin core antibody, tumour necrosis factor (TNF), and interleukin 1 (IL-1) levels were measured in 21 patients undergoing TAAA repair.

RESULTS

Intraoperative PMN CD11b expression was significantly greater in the 11 patients who developed pulmonary and renal complications than in those who made an uneventful recovery (P = 0.0009). In addition, CD11b expression during visceral reperfusion was preceded by a rise in plasma endotoxin level and a fall in antibody level (reflecting binding by absorbed endotoxin) which was significantly greater in patients who developed complications (P = 0.031 and P = 0.001 respectively). Plasma endotoxin level correlated with CD11b expression (r = 0.828, P = 0.001). There were no significant differences in intraoperative plasma levels of TNF and IL-1, or aortic cross-clamp times and blood transfusion volumes between the complicated and uncomplicated repairs.

CONCLUSION

Intraoperative neutrophil activation is a marker for the development of postoperative complications after TAAA reconstruction and is associated with endotoxin absorption.

Treatment of high-flow vascular malformations by venous embolization aided by flow occlusion techniques

PURPOSE

Transvenous embolization techniques may be helpful as alternatives to the arterial route when treating high-flow vascular malformations. We present our experience using these techniques in four patients.

METHODS

In one patient the venous portion of the arteriovenous malformation (AVM) was punctured directly; in the other three patients it was catheterized via a retrograde venous approach. Flow occlusion techniques were utilized in all patients during embolization, which was performed with absolute alcohol or N-butyl-2-cyanoacrylate.

RESULTS

Excellent clinical and angiographic results were obtained, with obliteration of arteriovenous shunting in all patients. There were no complications.

CONCLUSION

The embolization of certain AVMs using a venous approach is a safe and effective treatment.

Aortic prosthetic infection: 50 patients treated by radical or local surgery

Fifty patients with aortic prosthetic infection were managed in a period of 10 years from 1983 to 1993. Twenty-five patients had recurrent sepsis after local surgery (group 1) and 22 of these eventually required radical surgery. Twenty-five patients had radical graft excision as the first procedure (group 2). Group 1 contained an excess of patients with local groin symptoms (11 in group 1 versus five in group 2, P = 0.03) and in this group fewer radiological techniques were used to document the extent of graft infection. The perioperative mortality rate was similar in both groups (seven in group 1 versus five in group 2). The number of amputations was also similar (five in group 1 versus four in group 2). The triad of occlusive disease, aortobifemoral bypass and groin symptoms was associated with eight of nine amputations. While the authors would consider using local techniques if the anastomosis was intact, the graft remained patent and infection appeared to be confined to the groin, this combination is uncommon and radical graft excision remains the preferred treatment.

Detection and widespread distribution of Chlamydia pneumoniae in the vascular system and its possible implications

AIMS

To attempt to detect Chlamydia pneumoniae DNA in atheromatous vascular tissue.

METHODS

A modification of an existing polymerase chain reaction (PCR) assay and immunofluorescence staining with a monoclonal antibody directed against C pneumoniae were used to detect C pneumoniae. Specimens from 32 patients undergoing abdominal aortic aneurysm repair were examined. Vascular tissue, ostensibly normal, from six liver transplant donors was also examined for comparison. Altogether, 43 vessels from these 38 subjects (age range 36-85 years) were examined.

RESULTS

C pneumoniae was detected in 11 (44%) of 25 aortas, five (55%) of nine iliac arteries, two (40%) of five femoral arteries, and one of two iliac veins. Immunofluorescence staining supported positive PCR results in three of 12 cases in which it was used. Overall, C pneumoniae was detected in the arteries of 14 (44%) of the patients undergoing vascular surgery and three (50%) of the donors.

CONCLUSIONS

This study is the first in the UK in which C pneumoniae organisms have been found in atherosclerotic vessels and the tendency for the organisms to be present most often in such vessels exhibiting chronic inflammatory changes suggests that a search for them in various forms of arteritis may also be rewarding.

Surgical repair of thoracoabdominal aortic aneurysm: 10 years' experience

Between 1983 and 1993, a total of 110 patients underwent elective repair of thoracoabdominal aortic aneurysm. Mortality rate varied with the extent of repair: 26 per cent (five of 19) after type I repair, 42 per cent (eight of 19) after type II repair, 24 per cent (four of 17) after type III repair and 15 per cent (eight of 55) after type IV repair. A further 20 patients underwent urgent operation for suspected rupture in nine and true rupture in 11. The mortality rate was 73 per cent for those with true rupture and 33 per cent for those with threatened or contained rupture. Death was most commonly due to coagulopathy and bleeding (39 per cent) or myocardial ischaemia (19 per cent). Preoperative risk factors for death included type II repair, urgent or emergency operation, aortic dissection, impaired renal function and abnormal spirometry (P < 0.05). Postoperative risk factors included reoperation, dialysis or prolonged ventilation (P < 0.05). Twenty patients required dialysis; ten died, five recovered normal renal function and five were discharged on dialysis. Eight patients developed paraplegia and four of them died. Thoracoabdominal aneurysm remains a formidable surgical challenge, but 90 per cent of survivors are free of major morbidity.

Thrombolysis in arterial graft thrombosis

OBJECTIVE

to assess the impact of peripheral arterial thrombolysis for vascular graft occlusion.

DESIGN

Retrospective review.

SETTING

University Hospital.

MATERIALS

Thirty-one patients presented with 33 episodes of graft thrombosis.

CHIEF OUTCOME MEASURES

Successful thrombolysis in terms of total clearance or sufficient clearance to reveal an underlying factor responsible for graft failure.

MAIN RESULTS

Thrombolysis was successful in seven of 10 suprainguinal grafts (4 of 5 rtPA; 3 of 5 SK). One patient had failed lysis requiring an ilio-femoral graft. Of the seven patients with successful lysis, one required revision of a proximal anastomosis, two required distal anastomotic revisions, and one rethrombosed. Twenty-three thrombosed infrainguinal grafts were managed initially with intraarterial thrombolysis (9rtPA, 14 SK). Of 27 patients surviving at 30 days, seven required major amputation despite aggressive intervention.

CONCLUSIONS

Thrombosed suprainguinal grafts are amenable to thrombolysis and adjunctive surgery when necessary, with no major haemorrhagic complications. The majority of patients with thrombosed infrainguinal grafts require surgical intervention in order to preserve, or establish long term patency. For polytetrafluoroethylene (PTFE) grafts, thrombolysis was associated with poor success, haemorrhagic complications and a high amputation rate.

Colour flow imaging in the detection of femoro-distal graft and native artery stenosis: improved criteria

Vein graft or native artery stenosis after femoro-distal revascularisation is a common cause of graft occlusion. The early detection and treatment of such stenoses offers the potential for better graft patency than salvage procedures undertaken for graft thrombosis. In the past, two criteria using duplex scanning have been used to detect grafts at risk: (a) a localised increase in the peak velocity (V2) by 100% or more in comparison to the peak velocity (V1) 2 cm upstream (i.e. V2/V1 ratio greater than 2.0), and (b) a decrease in average peak velocity to less than 45 cm s-1. Seventy-four consecutive patients with femoro-distal vein grafts have been studied with intravenous digital subtraction angiography to detect stenosis (greater than 50% diameter) and colour flow imaging using both duplex scanning criteria (a) and (b) at 1.5, 3, 6, 9 and 12 months after operation. The results show that the V2:V1 ratio greater than criterion had a sensitivity of 100% and a specificity of 83%. Stenoses in the native distal arteries were not detected. Low average peak velocity less than 45 cm s-1 had a sensitivity of 61% and a specificity of 98%. By combining both criteria the sensitivity for detecting stenoses in both the vein graft and native distal artery, became 100% and the specificity 98%.

ABC of vascular diseases. Trauma

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The management of popliteal aneurysm: the importance of early surgical repair

A total of 58 popliteal aneurysms were found in 40 patients presenting between June 1982 and May 1989. Of these, 51 were caused by atherosclerosis, and there were five post-stenotic aneurysms associated with entrapment, one mycotic and one post-traumatic aneurysm. There were 18 patients with bilateral aneurysms, and two others had the first side repaired elsewhere before referral to this hospital. Aneurysms were found at other sites in 16 patients. Urgent treatment was needed for 32 patients (80%). Two required streptokinase treatment to clear arteries distally. Three needed fasciotomy for compartment syndrome. Two patients had above-knee amputation. Of 36 urgent operations, 13 had postoperative complications (36%). Four grafts were later revised successfully. At mean follow-up of 23 months (range 3-96 months), three patients had claudication secondary to preoperative distal arterial occlusion, and one patient had residual mild foot drop. These operative results contrast sharply with the low complication rate after elective operation for popliteal aneurysm. In these patients, 14 asymptomatic aneurysms were repaired uneventfully. Four patients who did not undergo elective operation later developed acute thrombosis (3) and rupture (1). This experience supports our policy that early elective treatment for popliteal artery aneurysm is the most appropriate choice.

Spontaneous abdominal arteriovenous fistulae: report of eight cases and review of the literature

The spontaneous rupture of an abdominal aneurysm into an adjacent major vein results in a profound and rapidly worsening haemodynamic disturbance. Survival depends on prompt diagnosis and closure of the fistula at operation. Eight cases are reported and modes of presentation, diagnostic criteria and management principles are reviewed in a detailed analysis of 148 cases in the English literature.

Graft stenosis: justification for 1-year surveillance

In all, 412 femorodistal grafts (femoropopliteal and femorocrural), performed between 1984 and 1988, have been prospectively studied at 6 weeks and 3, 6, 9 and 12 months after operation and at intervals of 6 months thereafter by duplex scanning and intravenous digital subtraction angiography. The overall incidence of stenoses was 16 per cent (femorocrural 20 per cent, femoropopliteal 15 per cent). All stenoses were detected in the first year after operation and none occurred after this. Twenty-four non-haemodynamically significant stenoses were not treated but were followed at intervals of 3 months. Forty-two haemodynamically significant stenoses were detected and secondary procedures were performed in 30 grafts at a mean of 8 months after surgery. Thirteen had percutaneous balloon dilatation and six (46 per cent) remain patent at a mean follow-up of 22 months. Two grafts which occluded within 30 days and three which restenosed at a mean of 8 months had tertiary procedures. Seventeen grafts were surgically revised, nine with patch grafts and eight with bypass grafts. Eleven of these remain patent at a mean follow-up of 30 months. One occluded immediately and three occluded late. Two grafts which restenosed at a mean of 19 months had successful tertiary procedures. In total, seven grafts had tertiary procedures (two had balloon dilatation and five had surgery) and six of these remain patent at a mean follow-up of 13.5 months. In conclusion, 37 procedures have been performed on 30 grafts, of which 23 (77 per cent) remain patent at a mean follow-up of 12 months. Approximately one-quarter of femorodistal grafts will develop graft-related stenoses and graft surveillance is worthwhile, but only for the first year after operation.

The response of peri-aneurysmal fibrosis--the "inflammatory" aneurysm--to surgery and steroid therapy

It is generally thought that the fibrotic process associated with an "inflammatory" aneurysm abates with operative repair. This paper reports a patient in whom the inflammatory process was accelerated after surgery leading to the development of subacute small bowel obstruction and worsening urinary tract obstruction in the postoperative period. Graft sepsis was suspected but all cultures were negative and his condition deteriorated on broad-spectrum antibiotics. Steroid therapy, however, resulted in a prompt reversal of symptoms, signs and objective evidence of obstruction. The problems of investigation of peri-aneurysmal fibrosis and graft sepsis are discussed. Possible aetiological factors and the relationship between the "inflammatory" aneurysm and idiopathic retroperitoneal fibrosis are considered.

Intraperitoneal placement of gentamicin beads in the management of prosthetic graft sepsis

A simple and non-hazardous technique for intraperitoneal placement of gentamicin beads after excision of an infected prosthetic aortic graft is presented. It has been used successfully in six cases of aortic graft sepsis.