Secondary amputation after lower extremity free-flap reconstruction

BACKGROUND

Microsurgical free-tissue transfer is often the definitive reconstructive option for lower extremity limb salvage. Despite an initial successful free-flap reconstruction, some patients ultimately undergo lower extremity amputation. The indications for secondary amputation include non- or malunion, infection, hardware failure, or chronic pain. This study aimed to identify the etiology and outcome of secondary amputation after lower extremity free-flap reconstruction.

METHODS

A retrospective cohort study was performed including patients who underwent lower extremity free-flap reconstruction from January 2002 to December 2020. Patients who underwent secondary amputation were identified. A survey based on the PROMIS® Pain Interference Scale and activities of daily living (ADLs) was then conducted to assess patient-reported outcomes. Fifteen (52%) patients who underwent amputation responded to the survey, with a median follow-up time of 4.4 years.

RESULTS

Of 410 patients who underwent lower extremity free-flap reconstruction, 40 (9.8%) patients underwent subsequent amputation. Of these, 10 patients had failed free-flap reconstruction and 30 patients had secondary amputation after an initially successful soft tissue coverage. The most common etiology for secondary amputation was infection (68%, n = 27). Eighty percent (n = 12) of survey respondents were able to use a prosthetic limb and ambulate.

CONCLUSIONS

The most common etiology of secondary amputation was infection. Most patients who ultimately underwent amputation were able to ambulate with a prosthetic, but the majority of patients reported chronic pain. This study could be used to guide potential free-flap candidates regarding the risks and outcomes of lower extremity free-flap reconstruction.

Is there an inter-manufacturer difference in generic clopidogrel response?

Background

Differences in platelet aggregation response to generic clopidogrel by manufacturer has not been investigated.

Purpose

Compare rates of clopidogrel response among patients receiving medication produced by two different manufacturers after acute coronary syndrome and/or percutaneous coronary intervention.

Methods

This quality improvement project included 515 adult patients receiving clopidogrel for acute coronary syndrome or ischemic heart disease and referred for coronary angiography/percutaneous coronary intervention at a large, public hospital. The project was divided into two phases: 1. retrospective collection of baseline data; 2. two 12-week, prospective phases in which all clopidogrel in the hospital was restricted to a single manufacturer at a time. The primary outcome was clopidogrel response measured by platelet function testing defined as ADP response <40% on light transmission aggregometry between two manufacturer groups. Aspirin response defined as arachidonic acid response <20% was also measured.

Results

Of 515 total patients included in both phases (mean [SD] age, 64.5 [11.4] years; 351 [68.2%] men; 450 [87.4%] ACS), 52% were found to be clopidogrel responders based on results of platelet function testing (Table 1 – select variables). Among 135 patients in the prospective phase, there was a significantly lower proportion of patients who were clopidogrel responders in the Manufacturer 1 group compared to the Manufacturer 2 group (34.8% vs. 55.1%, p=0.03) (Table 2 – select variables). After adjustment for age, sex, BMI, aspirin response, therapeutic hypothermia, LHC indication, clopidogrel loading dose, time between loading dose and lab measurement, and manufacturer, aspirin response (OR [95% CI]: 0.96 [0.95–0.97], p<0.001) and manufacturer (OR [95% CI]: 2.45 [1.18–5.22], p=0.02) were associated with clopidogrel response.

Conclusions

In a large public hospital, we observed that pharmacodynamic response to clopidogrel varied by drug manufacturer. Further investigation and/or regulation is needed to minimize inter-manufacturer variability.

Funding Acknowledgement

Type of funding sources: None.