European Journal of Cardiovascular Medicine

Anemia, defined by the World Health Organization as a condition in which the number of red blood cells or their oxygen-carrying capacity is insufficient to meet physiological needs, is a common concern in preoperative patients, particularly those undergoing vascular surgery. The prevalence of anemia in this patient cohort is notably higher due to factors such as chronic kidney disease, malnutrition, and the underlying vascular pathologies themselves. Anemia has been identified as an independent risk factor for adverse postoperative outcomes across various surgical fields, including increased perioperative transfusion requirements, prolonged hospital stays, and elevated morbidity and mortality rates.^[1][2]

The pathophysiological implications of anemia involve not only the reduction in oxygen transport capacity but also a compensatory increase in cardiac output, leading to potential cardiac stress. Furthermore, anemic patients are more susceptible to the effects of surgical blood loss and less able to compensate physiologically in the postoperative period, which may result in poorer wound healing, impaired immune response, and increased susceptibility to infections.^[3][4]

Despite its significance, the specific impact of preoperative anemia on outcomes following vascular surgeries — such as arterial revascularization procedures like aortobifemoral bypass, femoropopliteal bypass, femorotibial bypass and embolectomies or aneurysm repair — has not been extensively studied within a dedicated cohort. Vascular surgery patients represent a unique group where the consequences of preoperative anemia may be particularly pronounced due to the nature of the surgeries, which often involve significant blood loss and fluid shifts.^[5][6]

Aim

To investigate the impact of preoperative anemia on postoperative outcomes in patients undergoing vascular surgeries.

Objectives

1. To quantify the prevalence of preoperative anemia in patients scheduled for vascular surgeries.
2. To assess the relationship between the severity of preoperative anemia and the incidence of postoperative complications.
3. To evaluate the influence of preoperative anemia on the length of hospital stay and postoperative mortality in vascular surgery patients.

Source of Data

The data for this study were retrospectively collected from patient medical records at the Vascular Surgery Unit of General Surgery Department of Pacific Medical College & Hospital, Bhilon ka Bedla, Udaipur, Rajasthan-313024.

Study Design

This was a retrospective cross-sectional study aimed at understanding the correlations between preoperative anemia and various postoperative outcomes.

Study Location

The study was conducted at the Vascular Surgery Unit of General Surgery Department of Pacific Medical College & Hospital, Bhilon ka Bedla, Udaipur, Rajasthan-313024.

Study Duration

The data collection spanned from October 2023 to October 2024.

Sample Size

A total of 80 patients who underwent vascular surgeries were included in the study based on the inclusion and exclusion criteria.

Inclusion Criteria

Patients included were those aged 18 years and older who underwent elective or emergency vascular surgeries. Only patients with complete medical records and preoperative hemoglobin levels documented were considered.

Exclusion Criteria

Patients were excluded if they had received any form of blood transfusion or erythropoiesis-stimulating agents within three months prior to the surgery. Patients with other hematological diseases affecting red cell count or function, such as thalassemia or sickle cell disease, were also excluded.

Procedure and Methodology

Preoperative hemoglobin values were obtained from medical records, classified according to WHO guidelines for anemia, and correlated with postoperative outcomes such as complications, length of hospital stay, and mortality. Patient demographics, surgical details, and other relevant clinical data were also collected.

Sample Processing

Blood samples collected preoperatively were analyzed using a complete blood count (CBC) performed on a standard hematology analyzer to determine hemoglobin levels.

Statistical Methods

Data were analyzed using SPSS software. Descriptive statistics were used to summarize patient characteristics and hemoglobin levels. Inferential statistics, including chi-square and t-tests, were utilized to explore associations between anemia and postoperative outcomes. Logistic regression was performed to adjust for confounders.

Data Collection

Data collection was conducted through a comprehensive review of electronic health records, focusing on preoperative hemoglobin levels, and documented postoperative outcomes. Data entry and coding were carried out by trained personnel to ensure consistency and reliability.

Table 1: Impact of Preoperative Anemia on Postoperative Outcomes

This table investigates the relationship between preoperative anemia and various postoperative outcomes among vascular surgery patients. It reveals that anemic patients (n=45) experienced a higher incidence of major complications (20%) compared to non-anemic patients (n=35, 8.6%), with a statistically significant P value of 0.045. Similarly, minor complications were more frequent in anemic patients (28.9%) than in non-anemic patients (17.1%), with a P value of 0.034. The trend continues with reoperations, which were higher among anemic patients (8.9%) compared to non-anemic patients (2.9%), although this did not reach statistical significance (P value = 0.087). Mortality was observed only in the anemic group (4.4%), but the difference was not statistically significant (P value = 0.158).

Table 2: Prevalence of Preoperative Anemia

This table categorizes 80 patients by hemoglobin levels to establish the prevalence of preoperative anemia. It shows that 43.8% of patients had normal hemoglobin levels, while the remainder exhibited varying degrees of anemia: 31.2% had mild anemia, 18.8% had moderate anemia, and 6.2% had severe anemia. The overall prevalence of any degree of anemia was statistically significant with a P value of 0.001, indicating a high frequency of anemia among patients scheduled for vascular surgeries.

Table 3: Relationship Between Severity of Preoperative Anemia and Postoperative Complications

This table assesses how the severity of anemia among anemic patients (n=45) correlates with the incidence of postoperative complications. It shows that 48.9% of these patients did not experience any complications, while the rest suffered from mild (28.9%), moderate (15.6%), and severe complications (6.6%). The statistical analysis indicates significant correlations for mild (P value = 0.028) and moderate complications (P value = 0.042), suggesting that the severity of preoperative anemia is associated with an increased risk of postoperative complications.

Table 4: Influence of Preoperative Anemia on Length of Hospital Stay and Postoperative Mortality

This table examines the influence of preoperative anemia on the length of hospital stay and postoperative mortality among the study participants. Anemic patients had a significantly longer hospital stay of over 5 days (55.6%) compared to non-anemic patients (28.6%), with a P value of 0.009, indicating a notable impact of anemia on recovery time. However, the difference in mortality rates, though present (anemic patients 4.4% vs. non-anemic 0%), was not statistically significant (P value = 0.158), suggesting other factors may also influence mortality rates in these patients.

Table 1: Impact of Preoperative Anemia on Postoperative Outcomes This table shows a significant increase in both major and minor complications, as well as a trend towards increased reoperations and mortality in anemic patients compared to non-anemic patients undergoing vascular surgery. This observation aligns with findings from Phan K et al. (2017) ^[7], who noted that preoperative anemia is associated with adverse outcomes in patients undergoing major surgery. Furthermore, the increased risk of major complications and mortality in anemic patients corroborates the study by Jabagi H et al. (2019) ^[8], which highlighted a direct relationship between low preoperative hemoglobin levels and increased postoperative morbidity and mortality in vascular surgery.

Table 2: Prevalence of Preoperative Anemia The prevalence of preoperative anemia in this study (56.2% combined for mild, moderate, and severe anemia) is consistent with the rates reported in broader surgical populations, where anemia can affect 30-60% of patients depending on the surgical group and criteria for anemia LaPar DJ et al. (2018) ^[9]. The significant statistical finding (P=0.001) reinforces the concern that anemia is prevalent and often under-recognized in patients prior to undergoing major surgeries.

Table 3: Relationship Between Severity of Preoperative Anemia and Postoperative Complications This table highlights the gradation in risk for postoperative complications with increasing severity of anemia. Similar trends were documented by Ripoll JG et al. (2021) ^[10] & Von Heymann C et al. (2016) ^[11], who found that the severity of anemia correlated with an increase in both short-term and long-term postoperative complications. The significant findings for mild and moderate complications emphasize the need for preoperative correction of anemia, as suggested by Burton BN et al. (2018) ^[12], who argued that even mild anemia can substantially impact surgical outcomes.

Table 4: Influence of Preoperative Anemia on Length of Hospital Stay and Postoperative Mortality The findings from this table, indicating that anemic patients are more likely to have prolonged hospital stays, align with studies such as those by Gorla R et al. (2017) ^[13], which concluded that preoperative anemia was an independent predictor for longer hospitalization and higher re-admission rates. Although the difference in mortality was not statistically significant, the trend towards higher mortality in anemic patients is supported by the literature, including a meta-analysis by Tohme S et al. (2016) ^[14], which showed that anemia is associated with increased mortality risk in surgical patients.

Our study, systematically investigates the significant influence of preoperative anemia on the outcomes of patients undergoing vascular surgeries. The findings indicate a clear association between preoperative anemia and an increased incidence of both major and minor postoperative complications. Specifically, patients with anemia experienced a higher rate of major complications (20% vs. 8.6%), minor complications (28.9% vs. 17.1%), and a trend towards increased reoperation rates and mortality when compared to their non-anemic counterparts.

Furthermore, the prevalence of preoperative anemia in our patient cohort was notably high, with over half of the patients exhibiting some degree of anemia, emphasizing the need for heightened awareness and preoperative management strategies in this population. The relationship between the severity of anemia and the incidence of postoperative complications underscored that even mild forms of anemia could significantly impact patient outcomes, suggesting that more aggressive preoperative optimization might be warranted.

Additionally, anemic patients were more likely to experience extended hospital stays, which not only affects patient quality of life but also imposes additional burdens on healthcare resources. Although the increase in postoperative mortality among anemic patients was not statistically significant, the observed trend aligns with existing literature that links anemia with poorer overall surgical outcomes.

In conclusion, this study highlights the critical need for routine preoperative screening for anemia in patients scheduled for vascular surgeries. Implementing standardized protocols for the management of anemia, including potential treatments like iron supplementation or erythropoietin administration, could potentially improve postoperative outcomes. These findings advocate for a paradigm shift towards proactive preoperative care, aiming to correct anemia before surgery as a strategy to enhance patient safety, improve outcomes, and optimize healthcare utilization in this high-risk surgical population.

1. Cross-Sectional Design: One of the inherent limitations of this study stems from its cross-sectional design, which captures data at a single point in time. This design restricts our ability to establish causality between preoperative anemia and postoperative outcomes. Longitudinal studies would be more effective in delineating the temporal sequence and causative effects of anemia on postoperative results.
2. Sample Size: With a total of 80 patients, our study might lack the statistical power necessary to detect smaller differences in some of the outcomes, such as mortality rates. Larger studies could provide more definitive evidence and allow for more nuanced analysis of subgroups.
3. Single-Center Data: Data were collected from a single medical college hospital, which may limit the generalizability of the findings to other settings or populations. Multi-center studies could help validate our findings across diverse demographic and clinical environments.
4. Lack of Detailed Clinical Data: While we accounted for the presence of anemia, the study did not fully explore or adjust for all potential confounders such as the specific type or cause of anemia, patients' nutritional status, or the presence of other comorbid conditions, which could influence both anemia and surgical outcomes.
5. Retrospective Nature of Data Collection: Data collection was retrospective, relying on existing medical records, which may have issues with completeness and accuracy. Prospective data collection could enhance the quality and depth of data, including details on perioperative management and anemia treatment.
6. Definition and Classification of Anemia: The classification of anemia was based on hemoglobin levels alone without considering other parameters like iron stores, vitamin levels, or erythropoietin levels, which could provide a more comprehensive understanding of the anemia's etiology and severity.
7. Postoperative Follow-up Duration: The duration of postoperative follow-up might not have been long enough to capture all relevant outcomes, such as late postoperative complications or long-term mortality, which are crucial for a comprehensive assessment of the impact of preoperative anemia.
8. Selection Bias: The inclusion and exclusion criteria might have introduced selection bias, as certain patient groups, such as those who had received recent transfusions or treatments for anemia, were excluded. This could affect the applicability of the results to all vascular surgery patients.

1. Padmanabhan H, Siau K, Curtis J, Ng A, Menon S, Luckraz H, Brookes MJ. Preoperative anemia and outcomes in cardiovascular surgery: systematic review and meta-analysis. The Annals of thoracic surgery. 2019 Dec 1;108(6):1840-8.
2. Kougias P, Sharath S, Mi Z, Biswas K, Mills JL. Effect of postoperative permissive anemia and cardiovascular risk status on outcomes after major general and vascular surgery operative interventions. Annals of surgery. 2019 Oct 1;270(4):602-11.
3. Kougias P, Sharath S, Barshes NR, Chen M, Mills Sr JL. Effect of postoperative anemia and baseline cardiac risk on serious adverse outcomes after major vascular interventions. Journal of Vascular Surgery. 2017 Dec 1;66(6):1836-43.
4. Nandhra S, Boylan L, Prentis J, Nesbitt C. The influence of preoperative anemia on clinical outcomes after infrainguinal bypass surgery. Annals of Vascular Surgery. 2020 Jul 1;66:586-94.
5. Bodewes TC, Pothof AB, Darling JD, Deery SE, Jones DW, Soden PA, Moll FL, Schermerhorn ML. Preoperative anemia associated with adverse outcomes after infrainguinal bypass surgery in patients with chronic limb-threatening ischemia. Journal of vascular surgery. 2017 Dec 1;66(6):1775-85.
6. Natour AK, Shepard AD, Nypaver TJ, Rteil A, Corcoran P, Tang X, Kabbani L. Impact of preoperative anemia on hospitalization, death, and overall survival in patients with peripheral artery disease undergoing endovascular therapy: A retrospective cohort study in the United States and Canada. Journal of Endovascular Therapy. 2024 Oct;31(5):805-13.
7. Phan K, Dunn AE, Kim JS, Capua JD, Somani S, Kothari P, Lee NJ, Xu J, Dowdell JE, Cho SK. Impact of preoperative anemia on outcomes in adults undergoing elective posterior cervical fusion. Global Spine Journal. 2017 Dec;7(8):787-93.
8. Jabagi H, Boodhwani M, Tran DT, Sun L, Wells G, Rubens FD. The effect of preoperative anemia on patients undergoing cardiac surgery: a propensity-matched analysis. InSeminars in thoracic and cardiovascular surgery 2019 Jun 1 (Vol. 31, No. 2, pp. 157-163). WB Saunders.
9. LaPar DJ, Hawkins RB, McMurry TL, Isbell JM, Rich JB, Speir AM, Quader MA, Kron IL, Kern JA, Ailawadi G, Investigators for the Virginia Cardiac Services Quality Initiative. Preoperative anemia versus blood transfusion: which is the culprit for worse outcomes in cardiac surgery?. The Journal of thoracic and cardiovascular surgery. 2018 Jul 1;156(1):66-74.
10. Ripoll JG, Smith MM, Hanson AC, Schulte PJ, Portner ER, Kor DJ, Warner MA. Sex-specific associations between preoperative anemia and postoperative clinical outcomes in patients undergoing cardiac surgery. Anesthesia & Analgesia. 2021 Apr 1;132(4):1101-11.
11. Von Heymann C, Kaufner L, Sander M, Spies C, Schmidt K, Gombotz H, Wernecke KD, Balzer F. Does the severity of preoperative anemia or blood transfusion have a stronger impact on long-term survival after cardiac surgery?. The Journal of thoracic and cardiovascular surgery. 2016 Nov 1;152(5):1412-20.
12. Burton BN, Alison M, Brovman EY, Scott MJ, Urman RD, Gabriel RA. Optimizing preoperative anemia to improve patient outcomes. Anesthesiology Clinics. 2018 Dec 1;36(4):701-13.
13. Gorla R, Tsagakis K, Horacek M, Mahabadi AA, Kahlert P, Jakob H, Bossone E, Erbel R, Jánosi RA. Impact of preoperative anemia and postoperative hemoglobin drop on the incidence of acute kidney injury and in-hospital mortality in patients with type B acute aortic syndromes undergoing thoracic endovascular aortic repair. Vascular and endovascular surgery. 2017 Apr;51(3):131-8.
14. Tohme S, Varley PR, Landsittel DP, Chidi AP, Tsung A. Preoperative anemia and postoperative outcomes after hepatectomy. Hpb. 2016 Mar 1;18(3):255-61.