Gangrene of the Foot After Coronary Artery Bypass Graft Surgery



 
The Permanente Journal

Julia L Boland, MD1,2; Kristine Cueva, MD2; Jessica Pawly, MD2; Darius Shahbazi2,3; Maximillian Lee, MD1; Shahin Shahbazi, MD2

Perm J 2022;26:21.176 • E-pub: 04/05/2022 • https://doi.org/10.7812/TPP/21.176

Volume 26, Issue 1

Corresponding Author
Julia L Boland, MD
jboland@gwu.edu

Author Affiliations
1Department of Internal Medicine, George Washington University Hospital, Washington DC, USA

2Department of Internal Medicine, Kaiser Permanente, Sacramento, CA, USA

3Department of Neuroscience, Creighton University, Omaha, NE, USA

Author Contributions:
Julia L Boland, MD, participated in analysis of the data and drafting and submission of the final manuscript. Kristine Cueva, MD, and Jessica Pawley MD, participated in acquisition of the data and drafting of the final manuscript. Darius Shahbazi, Maximillian Lee MD, and Shahin Shahbazi, MD, participated in analysis of the data and drafting the final manuscript. All authors have given final approval to the manuscript.

Disclosures
Conflicts of Interest: None declared
Funding: None declared
Consent: Informed consent was received from all case patients.

Copyright Information
© 2022 The Permanente Federation. All rights reserved.

Abstract

Coronary artery bypass grafting (CABG) is the most common surgery performed by cardiothoracic surgeons worldwide. Risks of CABG include neurological outcomes, deep vein thrombosis, renal or gastrointestinal injury, and death. Perioperatively, some patients may need intra-aortic balloon pump (IABP) use to help assist with cardiac function. In this case, a 75-year-old man presented with multivessel myocardial infarction requiring IABP for cardiac assistance prior to undergoing CABG. Eighteen days after his CABG, his toes turned black at home. A CT angiogram showed aortic atherosclerosis, right tibioperoneal trunk stenosis, mild atherosclerotic right proximal anterior tibial artery stenosis, and multifocal occlusive lesions in the right and left infrapopliteal vessels. Vascular surgery performed balloon angioplasty of the right anterior tibial artery and podiatry performed a transmetatarsal amputation of the dry gangrene. The aim of this case report is to present a rare complication of CABG with peri-operative IABP use and to highlight the need for prompt diagnosis and treatment of dry gangrene.

Introduction

Coronary artery disease is the most common form of heart disease and the leading cause of death worldwide.1 In a myocardial infarction, atherosclerosis inside coronary arteries stenose the vessels, leading to ischemia and rupture of the thrombosis.2 Coronary artery bypass grafting (CABG) is a revascularization procedure that has been shown to lead to reduced mortality, reduced repeat myocardial infarctions compared to percutaneous coronary intervention.3 However, there are serious risks associated with CABG, including adverse neurologic outcomes such as stroke, requirement of mechanical circulation or ventilation support, deep vein thrombosis, renal failure, gastrointestinal injury, infection, and death.4,5 In the perioperative period, intra-aortic balloon pump (IABP) use is sometimes necessary to assist with cardiac output during acute myocardial infarction. Limb ischemia is a possible complication of IABP use with a rate of occurrence ranging from 1% to 31%.6

Case Report

A 75-year-old man with a past medical history of hypertension, type 2 diabetes mellitus, end-stage renal disease on peritoneal dialysis, paroxysmal atrial fibrillation on warfarin, and mild aortic stenosis presented to the emergency department with left sided chest pain that radiated to his left arm after walking approximately one mile. A review of systems was positive for shortness of breath, diaphoresis, and fatigue. He denied palpitations, nausea, vomiting, or abdominal discomfort. His recent history was significant for 3 days of mild chest pressure and left arm pain that was worse at night. His physical examination showed trace pedal edema but was otherwise unremarkable. His electrocardiogram showed normal sinus rhythm with a rate of 94 and ST depressions in I, avL, V5, and V6, which were new compared to his prior electrocardiogram. His echocardiogram demonstrated moderately decreased left ventricular systolic function with an ejection fraction of 40%, along with apical akinesis with anteroseptal marked hypokinesis.

He underwent cardiac catheterization, which showed critical left main stenosis, heavy calcification of the left main and proximal left-sided vessels, severe ostial left anterior descending artery stenosis, occlusion of the mid-left anterior descending, severe ostial, proximal, and mid-left circumflex artery disease, and moderate right coronary artery disease. Upon arrival at the catheter laboratory, the patient was in atrial fibrillation with rapid ventricular response. He converted to normal sinus rhythm after intravenous amiodarone.

An IABP was placed via the right common femoral artery for coronary perfusion, and he was referred to cardiothoracic surgery for CABG at a different facility, which was done 3 days after initial presentation. The left saphenous vein was harvested for his CABG. While an inpatient for his CABG, he was noted to have an ulcer to the right fourth toe without signs of cellulitis. The inpatient wound department care removed the right third toenail because it was loose and then provided local wound care. The patient applied antibiotics to the right toes postoperatively.

Eighteen days post CABG, the patient woke with new-onset painless color changes of his right toes and presented to the emergency department. Physical examination demonstrated dry gangrene of the right third and fourth toes (Figure 1) and erythema extending into the dorsum of the foot. The onset of these symptoms most likely occurred at home, given that dry gangrene usually takes several days to present. His femoral, popliteal, and radial pulses were palpated bilaterally and dorsalis pedis and posterior tibial pulses were weakly palpated bilaterally. A Doppler examination of his right foot demonstrated weak biphasic waveform in the dorsalis pedis and posterior tibial artery pulses. His right femoral region showed a healed catheter site and no mass, bruit, or tenderness. An x-ray of the foot was normal. He was started on broad spectrum antibiotics in the emergency room. An echocardiogram was done to rule out left ventricular thrombus. The patient had a CT angiogram (CTA) of the abdominal aorta that showed aortic atherosclerosis, severe ostial soft plaque causing right tibioperoneal trunk stenosis, and mild atherosclerotic right proximal anterior tibial artery stenoses. He had multifocal occlusive lesions in the right and left infrapopliteal vessels. He had a nonocclusive lower extremity arterial ankle-brachial index (Table 1).

tpj21176 g001

Figure 1: Initial presentation of gangrenous toes.

 Blood pressure (mmHg)ABI
Right    
Brachial 155  
Ankle PTA 67 0.42
Ankle DPA 150 0.94
Great toe 19  
Left    
Brachial 160  
Ankle PTA 85 0.53
Ankle DPA > 254  
Great toe 77  

Table 1: Ankle-brachial indexa

aThe right toe pressure of 19 mmHg does not predict for wound healing. The right leg demonstrates no substantial arterial occlusive disease with an ABI of 0.94. The left leg demonstrates moderate arterial occlusive disease with an ABI of 0.53.

ABI = ankle-brachial index; DPA = dorsalis pedis artery; PTA = posterior tibial artery.

The patient was discharged home with home health care and instructed to follow-up with podiatry and vascular surgery as an outpatient. At follow-up, the severity of his toes appeared to be progressively more gangrenous (Figure 2). The vascular surgery department performed balloon angioplasty of the right anterior tibial artery with 2.5–3.0 mm x 210 mm balloon. The podiatry department performed transmetatarsal amputation for definitive treatment of right foot digital gangrene. Findings included soft-tissue abscess of the dorsal and plantar forefoot at the base of digits, no soft-tissue necrosis at the level of amputation, and bone grossly viable at level of amputation. Intraoperative wound cultures demonstrated Escherichia coli, and the patient was treated with piperacillin-tazobactam and daptomycin. A summary of the case is shown in Table 2.

tpj21176 g002

Figure 2: Presentation of gangrenous toes 8 days after discharge from hospital.

DateRelevant history
 Summary of visitDiagnostic testsInterventions
Prior to admission Hypertension, type 2 diabetes mellitus, end-stage renal disease of peritoneal dialysis, paroxysmal atrial fibrillation on warfarin, mild aortic stenosis
ED presentation
  • – 3 day history of mild chest pressure and left arm pain, shortness of breath, diaphoresis, fatigue
  • – Trace pedal edema
  • – EKG: normal sinus rhythm, ST-segment depressions in leads aVL, V5, V6, new from prior
  • – Admission as NSTEMI
  • – Heparin drip
Admission
  • – Cardiac catheterization
  • – Development of afib with RVR
  • – Hypotension post-cath
  • – Transfer to ICU
  • – Referral to tertiary center for CABG
  • – Echocardiogram:
  • – moderately decreased LV systolic function with an EF of 40%, apical akinesis with anteroseptal marked hypokinesis
  • – Cardiac catheterization: critical left main stenosis, heavy calcification of the left main and proximal left-sided vessels, severe ostial LAD stenosis, occlusion of mid LAD, severe ostial, proximal, and mid-left circumflex disease, moderate RCA disease
  • – Cardiac catheterization for CAD
  • – IV amiodarone for afib with RVR
  • – Placement of IABP for postop hypotension
  • – Transfer to tertiary center for CABG
3 days after initial presentation to ED
  • – Transfer to outside hospital
  • – CABG performed
  • – Ulcer noted on right lower extremity fourth digit
 
  • – CABG with left saphenous vein graft
  • – Removal of right third digit toenail by wound care
  • – Topical antibiotics to toes
18 days post-CABG
  • – Sudden onset painless color changes of right toes
  • – Presentation to ED
  • – Lower extremity doppler: weak biphasic waveform of DP and PT pulses
  • – IV antibiotics
  • – Discharged home with home health with outpatient podiatry and
 
  • – Dry gangrene of right third and fourth toes, erythema extending to the dorsum of the foot
  • – Pulses present bilaterally
  • – X-ray R lower extremity: normal
  • – Echocardiogram: negative for LV or LA thrombus
  • – CT angiogram: aortic atherosclerosis, severe ostial soft plaque causing right tibio peroneal trunk stenosis and mild atherosclerotic right proximal anterior tibial artery stenosis, multifocal occlusive lesions in right and left infrapopliteal vessels
  • – ABI right lower extremity: 0.94
  • – vascular surgery follow-up
Outpatient follow-up
  • – Toes appeared more gangrenous
  • – Soft tissue abscess of the dorsal and plantar forefoot at base of digits
  • – Intraoperative wound cultures positive for E. coli
  • – Balloon angioplasty of right anterior tibial artery
  • – Transmetatarsal amputation
  • – Initiation of piperacillin-tazobactam and daptomycin

Table 2: Presentation of case

ABI = ankle-brachial index; CAD = coronary artery disease; CABG = coronary artery bypass grafting; DP = dorsalis pedis; ED = emergency department; EF = ejection fraction; EKG = electrocardiogram; IABP = intra-aortic balloon pump; ICU = Intensive Care Unit; LA = left anterior; LAD = left anterior descending; LV = left ventricular; NSTEMI = non-ST-elevation myocardial infarction; PT = posterior tibial; RCA = right coronary artery; RVR = rapid ventricular response.

Discussion

In this case, the differential diagnosis for this patient’s dry gangrene of the toes included aortic atheroma, cholesterol emboli, poor perfusion, deep venous thrombosis, heparin-induced thrombocytopenia (HIT), Buerger’s disease, trauma, and infectious process. This patient’s CTA showed aortic atherosclerosis, severe plaque in the distal popliteal artery, and multifocal occlusive lesions in the infrapopliteal vessels. These imaging findings suggest that cholesterol emboli or displaced aortic atheroma may have caused the ischemia. However, it is possible that poor perfusion from the IABP may have caused the dry gangrene. IABP use has been associated with serious vascular adverse effects including limb ischemia.6 Complications from IABP are more common in patients with a history of smoking, diabetes, hypertension, or peripheral vascular disease.6 Of note, this patient had a history of diabetes and hypertension. His echocardiogram lacked the clear presence of an LA or LV thrombus, making an intracardiac emboli unlikely but still possible. Deep venous thrombosis was unlikely as a cause of this patient’s gangrene because he had positive occlusive findings on CTA. Heparin was used in both the cardiac catheterization and CABG surgery for this patient. However, there was no thrombocytopenia and pretest probability of HIT based on the 4 Ts score was low in this case.7 Therefore, HIT is also unlikely to have caused this patient’s dry gangrene.

Acute ischemia is a known but rare complication following IABP and CABG. The objective of this case was to educate about the chance of gangrene requiring amputation after IABP use and CABG surgery. Prompt treatment of any skin color changes after IABP and CABG is warranted, and we advise warning patients of this possible risk to prevent them from delaying seeking care in the postoperative period.

Conclusion

We experienced a case of dry gangrene approximately 2 weeks following CABG with IABP use. Although generally considered safe, the risks of ischemia following CABG and IABP exist. Clinicians are encouraged to look for signs of ischemia in the postoperative patient following CABG and IABP.

References
1.     Regmi M, Siccardi MA. Coronary artery disease prevention. In: StatPearls Publishing. Treasure Island, (FL). 2020. https://www.ncbi.nlm.nih.gov/books/NBK547760/
2.     Ambrose JA, Singh M. Pathophysiology of coronary artery disease leading to acute coronary syndromes. F1000Prime Rep. 2015;7:08. DOI: https://doi.org/10.12703/P7-08
3.     Sipahi I, Akay MH, Dagdelen S, Blitz A, Alhan C. Coronary artery bypass grafting vs percutaneous coronary intervention and long-term mortality and morbidity in multivessel disease: Meta-analysis of randomized clinical trials of the arterial grafting and stenting era. JAMA Intern Med 2014;174(2):223–230. DOI: https://doi.org/10.1001/jamainternmed.2013.12844
4.     Safaie N, Montazerghaem H, Jodati A, Maghamipour N. In-hospital complications of coronary artery bypass graft surgery in patients older than 70 years. J Cardiovasc Thorac Res 2015;7(2):60–62. DOI: https://doi.org/10.15171/jcvtr.2015.13
5.     Lin CC, Wu MY, Tsai FC, et al. Prediction of major complications after isolated coronary artery bypass grafting: The CGMH experience. Chang Gung Med J 2010;33(4):370–379.
6.     de Jong MM, Lorusso R, Al Awami F, et al. Vascular complications following intra-aortic balloon pump implantation: An updated review. Perfusion 2018;33(2):96–104. DOI: https://doi.org/10.1177/0267659117727825
7.     Lo GK, Juhl D, Warkentin TE, Sigouin CS, Eichler P, Greinacher A. Evaluation of pretest clinical score (4 T’s) for the diagnosis of heparin-induced thrombocytopenia in two clinical settings. J Thromb Haemost 2006;4(4):759–765. DOI: https://doi.org/10.1111/j.1538-7836.2006.01787.x

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