Relationship between the Controlling Nutritional Status Score and Infrainguinal Bypass Surgery Outcomes in Patients with Chronic Limb-threatening Ischemia.

Online December 15, 2021 doi: 10.3400/avd.oa.21-00132 Ann Vasc Dis Vol. 14, No. 4; 2021; pp 334–340 Original Article Relationship between the Controlling Nutritional Status Score and Infrainguinal Bypass Surgery Outcomes in Patients with Chronic Limb-threatening Ischemia Satoshi Yamamoto, MD, PhD, Juno Deguchi, MD, PhD, Takuya Hashimoto, MD, PhD, Masamitsu Suhara, MD, PhD, and Osamu Sato, MD, PhD Objective: We investigated the association between Controlling Nutritional Status (CONUT) scores and the outcomes of bypass surgery in patients with chronic limbthreatening ischemia (CLTI). Methods: We retrospectively calculated preoperative CONUT scores in 118 patients (127 limbs) with CLTI who underwent infrainguinal bypass surgery. Survival, graft patency, and limb salvage were compared between the high and low CONUT score groups based on the respective cutoff points. Results: The median and mean CONUT scores were 5 and 4.8, respectively. The postoperative survival rate was lower in the high CONUT score (3–12) group than in the low CONUT score (0–2) group (P=0.0043). The limb salvage rate after arterial reconstruction was also significantly lower in the high CONUT score (8–12) group than in the low CONUT score (0–7) group (P=0.0009). Conclusions: The CONUT score can predict infrainguinal bypass surgery outcomes in patients with CLTI. (This is a translation of J Jpn Coll Angiol 2020; 60: 35–41.) Keywords: peripheral arterial disease, chronic limb-threatening ischemia, Controlling Nutritional Status Score, survival, limb salvage Department of Vascular Surgery, Saitama Medical Center, Saitama Medical University, Kawagoe, Saitama, Japan Received: November 17, 2021; Accepted: November 18, 2021 Corresponding author: Satoshi Yamamoto, MD, PhD. Department of Vascular Surgery, Saitama Medical Center, Saitama Medical University, 1981 Kamoda, Kawagoe, Saitama 3508550, Japan Tel: +81-49-228-3400, Fax: +81-49-228-3462 E-mail: This is a translation of J Jpn Coll Angiol 2020; 60: 35–41. ©2021 The Editorial Committee of Annals of Vascular Diseases. This article is distributed under the terms of the Creative Commons Attribution License, which permits use, distribution, and reproduction in any medium, provided the credit of the original work, a link to the license, and indication of any change are properly given, and the original work is not used for commercial purposes. Remixed or transformed contributions must be distributed under the same license as the original. 334 Introduction The prevalence of multiple diseases such as diabetes mellitus, ischemic heart disease, and renal failure is high among patients with chronic limb-threatening ischemia (CLTI), and their prognosis is usually poor. Patients with critical limb ischemia [The trans-Atlantic Inter-Society Consensus II (TASC II) grade] have a death rate of approximately 20% at 1 year after onset; therefore, their prognosis is worse than that of patients with malignant diseases.1,2) In the treatment of CLTI, it is necessary to consider the life expectancy of patients and determine the best treatment enabling limb salvage for each patient. Currently, although risk factors for death and major amputation of limbs have been reported, predictive indicators for life expectancy and limb salvage have not been established. Based on the Bypass versus Angioplasty in Severe Ischemia of the Leg (BASIL-2) trial, surgical bypass is recommended as the primary revascularization strategy when there is a suitable autologous vein graft and the patientʼs life expectancy is at least 2 years.3–5) However, it is difficult to predict whether patients will survive for more than 2 years, and the selection criteria for surgical bypass or endovascular treatment are practically undefined. Therefore, in clinical practice, surgical bypass is often avoided based on subjective judgment, and endovascular treatment, which can often be ineffective, is frequently and conveniently selected as the first choice of treatment. In contrast, although surgical bypass is performed actively and may lead to limb salvage, death sometimes occurs before the ulcer or necrosis has healed. When considering revascularization surgery in the treatment of CLTI, objective predictive indicators of life expectancy and limb salvage are desirable. In patients with CLTI, a single factor is unlikely to predict expectancy due to the diversity of comorbid diseases and the complexity of the pathological condition. For example, the serum levels of proteins, such as albumin, fluctuate highly due to inflammation, hepatic and renal Annals of Vascular Diseases Vol. 14, No. 4 (2021) CONUT Score and Bypass Surgery for Limb Ischemia functions, dehydration, and fluid infusion. However, a scoring system that combines multiple items can be useful in selecting a treatment strategy through comprehensive risk stratification. Multi-item nutritional and immunological evaluation indices have been reported to be useful as predictive indicators of mortality and related events.6,7) The Controlling Nutritional Status (CONUT) score, a multi-item nutritional evaluation measure, has been suggested to be useful as a factor predicting life prognosis in patients with gastrointestinal cancer and heart failure.8–13) However, it is unclear whether the CONUT score is useful in determining the expectancy of patients with CLTI after they have undergone surgical bypass surgery. When infrainguinal revascularization is required for CLTI treatment, it is necessary to consider surgical bypass even if other treatment options are chosen. In this study, we investigated the association between the CONUT score and treatment outcomes in patients with CLTI who underwent infrainguinal surgical bypass in our department. Subjects and Methods From 2008 to 2018, 127 limbs of 118 patients who underwent infrainguinal bypass surgery for CLTI with tissue loss due to atherosclerosis obliterans and whose CONUT scores could be calculated were included in the study. The CONUT score was calculated as the sum of scores for preoperative serum albumin level, total lymphocyte count, and total cholesterol level (Table 1). The risk group categorization for nutritional status based on the CONUT score was as follows: 0–1=normal, 2–4=mild, 5–8=moderate, and 9–12=severe.8) The values of each measurement were the most recent values measured before the revascularization procedure was performed (in principle, within 1 week for serum albumin level and total lymphocyte count and within approximately 1 month for total cholesterol level). As a surgical strategy, if the patient was judged to Table 1 be operable as per preoperative systemic evaluation, infrainguinal revascularization was actively performed for the purpose of limb salvage. Preoperative contrastenhanced computed tomography (CT), angiography, and ultrasonography were performed, and in principle, bypass surgery was considered to ensure in-line flow to the foot. Patients without an appropriate arterial anastomosis o (...truncated)