The importance of graft blood flow and peripheral outflow resistance for early patency in infrainguinal arterial reconstructions

The effect of congestive heart failure on perioperative outcomes in patients undergoing lower extremity revascularization

BACKGROUND

As the management of peripheral arterial disease evolves, determining the factors affecting the outcome of lower extremity interventions is important. The presence of peripheral arterial disease is associated with a twofold increase in the prevalence of congestive heart failure (CHF), with reports of increased perioperative complications. This study evaluated CHF as a predictor of acute postoperative complications in patients undergoing lower extremity bypass.

METHODS

The study group consisted of all patients entered in a prospective, multicenter database (American College of Surgeons National Surgical Quality Improvement Program) undergoing infrainguinal bypass (IIB) from 2005 to 2010. Patients with a new diagnosis of CHF ≤30 days before surgery were compared with those without such a diagnosis. Patency rates at 30 days, morbidity, and mortality were compared between groups using a multivariate logistic regression analysis controlling for covariates.

RESULTS

There were 18,645 IIB patients, of which 488 (2.6%) had history of CHF. CHF patients were older and had higher rates of comorbidities than those without CHF. In univariate analysis, IIB graft failure was not significantly different for patients with CHF (6.8%) vs those without (5.2%; P = .13). There was no difference in patency for femoral popliteal grafts (no CHF, 96.5%; CHF, 96.3%; P = .89) or for femoral-tibial grafts (no CHF, 91.9%; CHF, 89.3%; P = .20). However, CHF was significantly associated with postsurgery cardiac events (P = .007), pneumonia, prolonged intubation, reintubation, sepsis, return to the operating room, 30-day mortality, and length of stay >9 days (all P < .0001). After adjusting for covariates associated with CHF, compared with patients without CHF, those with CHF had an 82% higher odds of postoperative pneumonia (95% confidence interval [CI], 13%-94%; P = .014), an 87% increase in the odds of prolonged intubation (95% CI, 16%-201%; P = .011), a 73% increase in the odds of reintubation (95% CI, 12%-167%; P = .014), a 55% increase in the odds of sepsis or septic shock (95% CI, 11%-118%; P = .011), a 29% increase in the odds of returning to the operating room (95% CI, 4%-61%; P = .022), a 121% increase in the odds of 30-day mortality (95% CI, 56%-214%; P < .0001), and a 102% increase in the odds of postsurgery length of stay >9 days (95% CI, 64%-148%; P < .0001).

CONCLUSIONS

Recently diagnosed or exacerbated CHF does not affect acute IIB graft patency. However, CHF may increase the complication rates for perioperative pneumonia, prolonged intubation, reintubation, sepsis, return to the operating room, extended length of stay, and mortality. Therefore, before pursuing lower extremity interventions in patients with a history of CHF, one should incorporate an individualized approach to optimize the success of the revascularization while minimizing medical comorbidities.

Intra-operative Doppler Flow Measurement do not Predict ‘At-risk’ Status of Infrainguinal Bypass Grafts

AIMS

Patients undergoing infrainguinal arterial reconstruction using vein conduits, frequently undergo intra-operative Doppler flow measurements to determine technical adequacy. The aim of this study was to determine the proportion of vein grafts with normal intra-operative haemodynamic parameters that were subsequently discovered to be 'at risk' on post-operative duplex surveillance scanning.

METHODS

We prospectively collected data on 82, primary infrainguinal vein bypass grafts. Post papaverine graft flow and peripheral resistance were measured using the Scimed Opdop intra-operative Doppler machine. All grafts were determined to be technically adequate on the basis of measured peripheral resistance units (mPRU) being < or =1. At 1 week, a post-operative duplex surveillance scan was performed. At risk status was determined and compared to the intra-operative Doppler flow measurement. Statistical analysis was performed using the Mann-Whitney U-test.

RESULTS

The post-operative duplex scan demonstrated that 53 (65%) of the 82 vein bypass grafts were diagnosed as being 'not at risk'; and 29 (35%) were regarded as at risk. When the groups were compared, there was no significant difference in intra-operative haemodynamic parameters between those not at risk and those at risk (P=0.19, Mann-Whitney U-test). The 1 month primary patency rate was 79% with a secondary patency rate of 100%.

CONCLUSION

Despite normal intra-operative Doppler flow measurements, 35% of vein grafts were regarded as being at risk at the 1 week post-operative duplex surveillance scan. No single value may be universally applicable for identifying at risk grafts intraoperatively. Indeed, graft failure appears to be a multifactorial process.

Multi Centre Study to Assess the Feasibility of a New Covered Stent and Delivery System in Combination with Remote Superficial Femoral Artery Endarterectomy (RSFAE)

OBJECTIVES

To evaluate the feasibility and efficacy of an innovative new covered stent and adjustable deployment system (aSpire Covered Stent, Vascular Architects Inc., San Jose, CA, USA) in combination with remote superficial femoral artery endarterectomy (RSFAE) for the treatment of long segment femoropopliteal occlusive disease.

DESIGN

Prospective multi-centre trial.

MATERIALS AND METHODS

Sixty-two limbs in 61 patients (41 men; median age 69 years, range 40-88) with severe disabling claudication (n=56) or critical limb ischaemia (n=6) were treated in five European centres with aSpire stenting after RSFAE for long segment occlusions (mean length 25 cm). Follow-up was by duplex scanning at 1-, 6-, 12- and 18-months. Primary, primary-assisted and secondary patency rates were analysed.

RESULTS

The median follow-up was 17 (range 2-34) months. A mean of 1.3 stents (range 1-3) were deployed with a median stent diameter of 7 mm (range 6-9). There were one early and 24 late failures. At 18-months the cumulative primary, primary-assisted and secondary patency rates were 60, 70 and 72%, respectively. There were no device related adverse events, such as kinking or fracturing and no stent migrations.

CONCLUSIONS

The aSpire stent and the delivery system are both safe and feasible in combination with RSFAE. The mid term follow-up appears favourable in view of the long segment occlusions treated. Further follow-up is required to compare the mid- and long-term outcomes with current stents and conventional femoropopliteal bypass.