Intraoperative temperature management and its effect on surgical outcomes in elderly patients undergoing lichtenstein unilateral inguinal hernia repair

Xiawei Zheng; Min Zhang

doi:10.1515/med-2025-1324

Article Open Access

Intraoperative temperature management and its effect on surgical outcomes in elderly patients undergoing lichtenstein unilateral inguinal hernia repair

Xiawei Zheng and Min Zhang

Published/Copyright: December 17, 2025

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From the journal Open Medicine Volume 20 Issue 1

Abstract

Objectives

Unilateral inguinal hernia repair is common in elderly patients, but postoperative complications and recurrence remain concerns. Intraoperative factors such as body temperature, surgical duration, and blood loss may influence outcomes. This study evaluated the impact of intraoperative temperature, surgical duration, and blood loss on postoperative complications and recurrence in elderly patients undergoing Lichtenstein unilateral inguinal hernia repair.

Methods

We retrospectively analyzed clinical data from 368 patients treated between 2018 and 2023. Intraoperative hypothermia was defined as body temperature<36 °C. Postoperative outcomes, including complications and recurrence, were assessed. Predictive performance was evaluated using receiver operating characteristic (ROC) curves.

Results

Intraoperative hypothermia was strongly associated with postoperative wound infections, hematomas, and recurrence, and was identified as an independent prognostic factor. Patients with hypothermia showed longer operative times, greater inflammatory responses, and higher recurrence rates compared with normothermic patients. Excessive blood loss and prolonged surgical duration also increased complication risk. ROC analysis confirmed intraoperative temperature as the strongest predictor of poor outcomes, with an optimal cutoff of 36.25 °C.

Conclusions

Normothermia maintenance, shortened operative time, and minimized blood loss are critical to improving outcomes in elderly patients. Temperature control represents a key modifiable factor to reduce complications and recurrence.

Keywords: unilateral inguinal herni repair; intraoperative temperature; postoperative complications; recurrence; elderly patients

Introduction

Inguinal hernia is one of the most common conditions in general surgery [1]. Its incidence increases with aging, as abdominal muscle atrophy and metabolic decline predispose elderly individuals to a higher risk compared with younger patients [2], [3], [4]. Elderly patients account for over 30 % of all cases, with a prevalence of approximately 1.15 % in those aged 60 years or older [5]. In China, approximately 1.5 million repairs are performed annually. Although surgery is effective, complication rates in elderly patients reach 4.2 %, significantly higher than in younger groups [6], 7]. Clinically, inguinal hernia is predominantly unilateral, with most series reporting a higher proportion of unilateral cases [1], 8]. These features underscore the importance of perioperative risk control in elderly patients with unilateral inguinal hernia.

Evidence indicates that intraoperative factors such as body temperature, surgical duration, and blood loss are strongly associated with complications and recurrence after inguinal hernia repair. Although postoperative hematoma is relatively uncommon, it correlates with these intraoperative variables and may predispose to infection and recurrence, underscoring the need for strict control of operative time and bleeding in unilateral repairs [9]. Perioperative temperature is another critical determinant: normothermia supports metabolic and immune function, whereas hypo- or hyperthermia worsens outcomes [10]. Open hernia repair carries a higher risk of hypothermia, particularly in elderly patients with impaired thermoregulation [11], 12]. Hypothermia suppresses immunity and induces inflammatory responses, thereby increasing the risk of infection [13]. Inflammatory markers, such as the white blood cell count (WBC) and the neutrophil-to-lymphocyte ratio (NLR), reflect systemic inflammation [14], 15]. Additionally, neutrophils further exacerbate postoperative inflammation through the release of cytokines and chemokines [16].

Although evidence from meta-analyses and systematic reviews supports surgical decision-making in unilateral hernia repair, limitations persist. Comparative studies of Lichtenstein and TAPP in unilateral, primary hernias have focused on perioperative outcomes across techniques, without addressing intraoperative modifiable factors such as temperature, duration, and blood loss [17]. Furthermore, while meta-analyses include data on unilateral primary inguinal hernia [18], 19], subgroup analyses specific to elderly unilateral patients are lacking, and systematic evaluations of intraoperative variables as independent predictors of complications and recurrence are absent. These gaps underscore the need to clarify how intraoperative temperature, surgical duration, and blood loss collectively impact postoperative outcomes in elderly patients with unilateral inguinal hernias.

This study aims to determine the effects of intraoperative temperature, surgical duration, and blood loss on postoperative complications and recurrence in elderly patients undergoing unilateral inguinal hernia repair. By leveraging large-sample retrospective data and conducting multifactorial linkage analysis, this research seeks to elucidate the relationship between modifiable intraoperative factors and adverse outcomes, thereby addressing existing evidence gaps. Such work has important implications for expanding the mechanistic understanding of intraoperative risks in unilateral inguinal hernia repair and for providing evidence-based guidance to optimize perioperative management, ultimately reducing complications and recurrence while improving long-term outcomes in elderly patients.

Materials and methods

Clinical data collection and sources

This retrospective study included patients who underwent unilateral inguinal hernia repair at our institution between January 2018 and December 2023, with follow-up through December 2024. Demographic data (age, sex, and comorbidities such as hypertension and diabetes) were extracted from electronic medical records. Intraoperative variables were obtained from the surgical management system, including procedure code, surgical approach (Lichtenstein tension-free repair with mesh plug), body temperature, operative time, and blood loss. Postoperative outcomes were collected from institutional follow-up records, including length of stay, complications (e.g., wound infection, hematoma), and recurrence within 12 months. Complications were classified using the Clavien-Dindo system. Hernia recurrence was uniformly evaluated through outpatient physical examination combined with groin ultrasonography, while equivocal cases underwent postoperative re-examination or confirmation at reoperation. Body temperature was continuously monitored using standardized devices throughout the pre-, intra-, and postoperative phases to ensure consistency. The operating room temperature was maintained at 22–24 °C with controlled humidity; however, active warming devices were not routinely applied, as they are not standard in general surgery at our center and are limited by cost and workflow considerations. Thus, intraoperative hypothermia, when present, occurred without deliberate intervention. All data were de-identified before analysis. This study was approved by the institutional ethics committee (Approval No. KY2024506) and adhered to relevant ethical standards, ensuring strict protection of patient confidentiality.

Inclusion and exclusion criteria

The inclusion criteria were patients surgically confirmed to have a unilateral inguinal hernia during the study period who underwent Lichtenstein tension-free repair, completed at least 12 months of follow-up, and had complete electronic medical records. To reduce surgical complexity and ensure consistency of intraoperative variables (e.g., operative time and blood loss), cases of bilateral inguinal hernia were excluded.

Exclusion criteria were: (1) incomplete data, such as missing operative records or intraoperative temperature measurements; (2) uncertain diagnosis or lack of confirmation by both surgery and imaging; (3) failure to complete postoperative follow-up; (4) unstable comorbidities or very short disease duration, which might exert extreme effects on postoperative recovery; and (5) complex hernias, including irreducible, incarcerated, recurrent hernias, EHS grade≥L3 large hernias, or hernias involving multiple organs, to ensure clinical homogeneity and minimize confounding factors (Figure S1).

Surgical method

All patients underwent standardized unilateral inguinal hernia repair using the Lichtenstein tension-free mesh plug technique, performed by senior attending surgeons to ensure procedural consistency. Intraoperative body temperature was continuously monitored using electronic devices, but temperature management remained observational, without active warming interventions.

Anesthesia

All patients received spinal anesthesia. Inguinal hernia repair is commonly performed under spinal anesthesia, as it exerts minimal effects on respiratory function, provides greater hemodynamic stability, and is particularly suitable for elderly patients [20], 21]. In this study, 0.5 % hyperbaric bupivacaine (1.5–2.0 mL) was administered via lumbar puncture to achieve a sensory block at the T10-T12 level. All procedures were conducted by senior anesthesiologists, with continuous intraoperative monitoring of vital signs to ensure standardization and patient safety.

Observation indicators

The primary outcome measures included postoperative complications (e.g., wound infection, hematoma, recurrence), length of hospital stay, postoperative recovery, and recurrence within 12 months after surgery. Postoperative complications were graded using the Clavien-Dindo classification. Hernia recurrence was evaluated through outpatient physical examination and groin ultrasonography, with equivocal cases confirmed at reoperation. Intraoperative temperature was analyzed as a key factor influencing postoperative recovery, complications, and recurrence. Additionally, secondary clinical indicators such as intraoperative blood loss and surgical duration were recorded to further evaluate their potential impact on surgical prognosis (Table 1).

Table 1:

Comparison of clinical data.

Clinical data	Hypothermia group	Normal temperature group	χ² /t	p-Value
Number of cases	40	338
Age (years, Mean ± SD)	72.50 ± 5.46	74.53 ± 7.05	−1.262	0.208
Gender [cases, %]			3.363	0.067
Male	24 (60.0)	263 (77.8)
Female	16 (40.0)	75 (22.2)
BMI (kg/m², Mean ± SD)	23.88 ± 3.34	25.20 ± 3.49	−1.648	0.100
Comorbidity [cases, %]			3.186	0.074
Yes	18 (45.0)	90 (26.6)
No	22 (55.0)	248 (73.4)
ASA grade			3.490	0.062
I/II grade	28 (70.0)	289 (85.5)
III/IV grade	12 (30.0)	49 (14.5)
Preoperative WBC level (×10⁹ L⁻¹)	7.39 ± 1.69	7.93 ± 1.42	−1.626	0.105
Preoperative NLR	1.73 ± 0.30	1.62 ± 0.24	1.904	0.058
Operation time (min, Mean ± SD)	98.45 ± 12.31	90.87 ± 13.61	2.431	0.016
Blood loss (ml, Mean ± SD)	82.00 ± 14.03	75.98 ± 13.79	1.895	0.059
Intraoperative temperature (°C, Mean ± SD)	35.46 ± 0.26	36.52 ± 0.23	−19.975	<0.001
Postoperative WBC level (×10⁹ L⁻¹)	12.67 ± 1.33	11.94 ± 1.40	2.301	0.022
Postoperative NLR	4.29 ± 0.95	3.69 ± 0.88	2.932	0.004
Complications [cases, %]			9.50	0.0021
Yes	4 (10.0)	4 (1.18)
No	36 (90.0)	334 (98.82)

BMI, body mass index; WBC, postoperative peripheral blood leukocyte count; NLR, neutrophil to lymphocyte ratio.

Sample size calculation

To ensure the statistical reliability of the study results, we performed a power analysis using R software. Based on an expected effect size (Cohen’s d=0.5, indicating a moderate effect), the significance level was set at 0.05, with a target statistical power of 80 %. The analysis determined that a sample size of 40 patients in the hypothermia group and 338 patients in the normothermia group would achieve 80 % power to detect significant differences between groups. It confirms that the current sample size is sufficient to meet standard statistical requirements, ensuring the robustness and reliability of the study findings.

Statistical analysis

Data analysis was conducted using R software (version 4.0.3). Continuous variables were presented as mean ± standard deviation (Mean ± SD), with group differences assessed using independent sample t-tests or the Mann-Whitney U test, depending on the data distribution. Categorical variables were expressed as frequencies and percentages, with comparisons made using chi-square tests. Changes in postoperative immune response indicators, such as WBC and NLR, were analyzed using paired t-tests. A one-way analysis of variance (ANOVA) was performed to compare multiple groups. Multiple linear regression analysis was conducted to evaluate the independent effect of intraoperative temperature on postoperative recovery, while adjusting for potential confounding variables, including age, sex, and comorbidities. Receiver operating characteristic (ROC) curve analysis was further applied to assess the predictive ability of intraoperative temperature, postoperative WBC, and NLR for poor prognosis, with the area under the curve (AUC), optimal cutoff values, sensitivity, and specificity calculated. All statistical tests were two-tailed, and a p-value < 0.05 was considered statistically significant.

Ethical statement

This study was approved by the Clinical Ethics Committee of The Affiliated Hospital of Southwest Medical University (No. KY2024506).

Results

Patient characteristics

This study included 368 patients who underwent unilateral inguinal hernia repair, with 40 patients (10.8 %) in the hypothermia group and 328 (89.2 %) in the normothermia group. The cohort comprised 263 male patients (77.8 %) and 75 female patients (22.2 %). The age range was 65–85 years, with an average age of 72.5 ± 5.46 years in the hypothermia group and 74.53 ± 7.05 years in the normothermia group, with no significant difference between groups (p=0.208). Additionally, there were no significant differences in sex distribution, body weight, height, or BMI between the two groups (p>0.05). In the hypothermia group, the median duration of intraoperative hypothermia (<36 °C) was 42 min (IQR: 35–52 min).

Preoperative WBC was 7.39 ± 1.69 × 10⁹/L in the hypothermia group and 7.93 ± 1.42 × 10⁹/L in the normothermia group (p=0.105). The NLR was 1.73 ± 0.30 in the hypothermia group and 1.62 ± 0.24 in the normothermia group (p=0.058). Regarding surgical parameters, the mean surgical duration was 98.45 ± 12.31 min in the hypothermia group and 90.87 ± 13.61 min in the normothermia group, with a statistically significant difference (p=0.016). The mean intraoperative blood loss was 82.00 ± 14.03 mL in the hypothermia group and 75.98 ± 13.79 mL in the normothermia group, though this difference did not reach statistical significance (p=0.059).

Intraoperative temperature was significantly different between the two groups, with a mean temperature of 35.46 ± 0.26 °C in the hypothermia group and 36.52 ± 0.23 °C in the normothermia group (p<0.001).

Postoperative WBC was significantly higher in the hypothermia group (12.67 ± 1.33 × 10⁹/L) compared to the normothermia group (11.94 ± 1.40 × 10⁹/L, p=0.022). Similarly, the NLR was elevated in the hypothermia group (4.29 ± 0.95) compared to the normothermia group (3.69 ± 0.88, p=0.004).

The hypothermia group showed longer operative times, elevated postoperative WBC and NLR, and a median hypothermia duration of 42 min, indicating its potential to exacerbate inflammation and increase complication risk.

Independent risk factors for poor prognosis in elderly patients undergoing inguinal hernia repair

Multivariate logistic regression identified postoperative NLR≥1.665 (OR=3.116, 95 % CI: 1.665–5.833, p<0.001), intraoperative blood loss (per mL, OR=1.060, 95 % CI: 1.010–1.113, p=0.019), and age (per year, OR=1.085, 95 % CI: 1.001–1.175, p=0.048) as independent predictors of poor prognosis after unilateral inguinal hernia repair in elderly patients (Table 2). Hypothermia (<36 °C) was also associated with increased risk (OR=6.865, 95 % CI: 1.131–41.661, p=0.036). Other factors, including sex, BMI, comorbidities, ASA classification, preoperative WBC, and surgical duration, were not significant (Figure 1). These results highlight NLR, blood loss, age, and perioperative hypothermia as critical variables influencing postoperative outcomes, underscoring the need for targeted intraoperative management.

Table 2:

Multivariate logistic regression analysis of prognostic factors for elderly inguinal hernia repair outcomes.

Factor	β	SE	Wald 2	p-Value	OR	95 % CI
Age	0.081	0.041	3.909	0.048	1.085	1.001 ∼ 1.175
Gender	−0.653	0.604	1.169	0.280	0.521	0.159 ∼ 1.700
BMI	0.077	0.081	0.917	0.338	1.081	0.922 ∼ 1.266
Comorbidity	0.340	0.675	0.254	0.614	1.405	0.374 ∼ 5.272
ASA grade	0.985	0.924	1.138	0.286	2.679	0.438 ∼ 16.379
Preop WBC level	0.174	0.229	0.580	0.446	1.190	0.760 ∼ 1.864
Preop NLR	0.310	1.041	0.089	0.766	1.364	0.177 ∼ 10.493
Operation time	0.005	0.021	0.053	0.818	1.005	0.964 ∼ 1.048
Blood loss	0.058	0.025	5.513	0.019	1.060	1.010 ∼ 1.113
Postop WBC level	0.364	0.167	4.744	0.029	1.438	1.037 ∼ 1.995
Postop NLR	1.137	0.320	12.628	<0.001	3.116	1.665 ∼ 5.833
Group	1.926	0.920	4.385	0.036	6.865	1.131 ∼ 41.661

Figure 1:

Multivariate logistic regression analysis of risk factors for poor prognosis in elderly patients undergoing unilateral inguinal hernia repair.

Predictive performance of intraoperative temperature, postoperative WBC, and NLR for prognosis

ROC curve analysis demonstrated differential predictive performance among the three markers (Table 3). Postoperative WBC showed the lowest predictive value (AUC=0.678, 95 % CI: 0.616–0.741), although its relatively high specificity (72.9 %) suggests an association with infection or severe inflammation (Figure 2A). Postoperative NLR exhibited stronger predictive performance (AUC=0.730, 95 % CI: 0.675–0.786) with an optimal cutoff of 4.03 (sensitivity 58.9 %, specificity 74.5 %), consistent with its role as a systemic inflammatory marker (Figure 2B). Intraoperative temperature demonstrated the highest predictive efficacy (AUC=0.777, 95 % CI: 0.727–0.828) with an optimal cutoff of 36.25 °C (sensitivity 81.3 %, specificity 62.5 %), confirming hypothermia as a critical prognostic risk factor (Figure 2C). Overall, intraoperative temperature was the strongest predictor, followed by postoperative NLR, whereas WBC may serve as an auxiliary indicator in clinical risk assessment.

Table 3:

ROC curve of intraoperative temperature, postoperative WBC levels, and NLR in predicting surgical outcomes.

Factor	AUC (95 % CI)	SE value	p-Value	Cutoff value^a	Sensitivity, %	Specificity, %
Postoperative WBC level	0.716 (0.605, 0.827)	0.056	0.001	12.03	60.0	72.5
Postoperative NLR	0.804 (0.698, 0.910)	0.054	<0.001	4.03	80.0	75.7
Intraoperative temperature	0.812 (0.686, 0.937)	0.064	<0.001	36.25	75.0	88.8

^aThe ideal cutoff value is calculated based on the Youden Index.

Figure 2:

ROC curves for intraoperative temperature, postoperative WBC levels, and NLR in predicting surgical prognosis. (A) ROC curve for postoperative WBC levels (AUC=0.678, 95 % CI: 0.616–0.741); (B) ROC curve for postoperative NLR (AUC=0.730, 95 % CI: 0.675–0.786); (C) ROC curve for intraoperative temperature (AUC=0.777, 95 % CI: 0.727–0.828).

Relationship between intraoperative temperature and postoperative complications

Furthermore, this study analyzed the impact of intraoperative temperature on the incidence of postoperative complications, revealing a significant effect. The hypothermia group (intraoperative temperature<36 °C) exhibited a substantially higher rate of postoperative complications compared to the normothermia group (36.5°C–37.5 °C) (p<0.001). Specifically, the overall postoperative complication rate in the hypothermia group was 10.0 % (4/40), whereas in the normothermia group, it was 1.18 % (4/338). Among hypothermic patients, the incidence of surgical site infection and hematoma was 7.5 % (3/40) and 2.5 % (1/40), respectively, compared to 0.59 % (2/338) and 0.59 % (2/338) in the normothermia group. These findings indicate that low intraoperative temperature significantly increases the risk of postoperative complications, particularly surgical site infections and hematomas (Table 1).

Relationship between intraoperative temperature and length of hospital stay

Patients with intraoperative hypothermia (<36 °C) had significantly longer hospital stays compared with normothermia cases (8 ± 5 vs. 4 ± 1 days, p<0.01) (Figure 3A). Greater intraoperative temperature variability (SD>0.5 °C) was also associated with prolonged hospitalization (9 ± 6 vs. 4 ± 1.5 days, p<0.05) (Figure 3B). These findings suggest that hypothermia and temperature fluctuations are closely linked to extended hospital stay, potentially through mechanisms such as physiological stress, delayed immune recovery, and increased complication risk. Effective intraoperative temperature management and stability maintenance may therefore be essential for reducing hospitalization and improving recovery.

Figure 3:

Impact of intraoperative temperature and temperature variability on length of hospital stay. (A) Box plot of intraoperative temperature and length of hospital stay; (B) Box plot of temperature variability and length of hospital stay.

Relationship between intraoperative temperature and postoperative recurrence rate

The association between intraoperative temperature and postoperative recurrence was further evaluated. The association between intraoperative temperature and postoperative recurrence was analyzed. The recurrence rate in the hypothermia group (<36 °C) was 5 %, significantly higher than the 3.25 % observed in the normothermia group (36–37 °C) (p<0.05). A greater proportion of recurrence cases was seen in the hypothermia group, as indicated by the larger dark blue segment in Figure 4, whereas the normothermia group showed a smaller recurrence proportion. These findings suggest that intraoperative hypothermia may increase the risk of recurrence after unilateral inguinal hernia repair, underscoring the importance of temperature management during surgery.

Figure 4:

Bar chart of intraoperative temperature and postoperative recurrence rate. Comparison of postoperative recurrence rates between the hypothermia and normothermia groups. The bar chart illustrates the proportion of patients with recurrence (dark blue) and no recurrence (light blue) in each group. p<0.05 indicates a statistically significant difference between groups.

Discussion

Unilateral inguinal hernia repair is a common surgical procedure; however, the occurrence of postoperative complications and recurrence remains a significant concern for patient health [22], [23], [24], [25]. While numerous studies have focused on surgical treatment and postoperative management of unilateral inguinal hernia, research on how intraoperative factors influence postoperative complications and recurrence rates remains limited. This study conducted a retrospective analysis to examine the relationship between intraoperative temperature, surgical duration, and blood loss with postoperative complications and recurrence following unilateral inguinal hernia repair. The findings indicate that intraoperative hypothermia, prolonged surgical duration, and excessive blood loss are significantly associated with an increased risk of postoperative complications and recurrence. Specifically, hypothermia not only elevates the risk of postoperative complications but also correlates positively with recurrence. Our findings align with previous research while addressing the knowledge gap regarding the impact of intraoperative temperature on recurrence mechanisms. This study offers new theoretical insights for optimizing clinical strategies in unilateral inguinal hernia repair by providing a detailed analysis of intraoperative factors, particularly temperature management. For elderly patients, effective intraoperative temperature control, reducing surgical duration, and minimizing blood loss may be crucial in improving surgical outcomes. This discovery holds significant clinical value and innovation, guiding future surgical practices and postoperative management.

In comparison to existing literature, this study validates previous findings and offers deeper insights into the impact of intraoperative factors on postoperative complications and recurrence. Prior research has widely recognized the association between intraoperative hypothermia and postoperative infections and complications [26], [27], [28]. However, this study is the first to establish that intraoperative hypothermia is linked not only to complication rates but also to an increased risk of postoperative recurrence, offering important clinical implications. Previous studies have primarily focused on hypothermia-induced immune suppression and heightened infection risk [13]. In contrast, this study further elucidates the potential connection between hypothermia and the recurrence of disease. A possible mechanism is that hypothermia exacerbates immune responses and cytokine release, thereby impairing postoperative wound healing and immune function, ultimately increasing recurrence risk. Additionally, this study confirms that surgical duration and blood loss significantly influence complication rates. Prolonged surgical duration and excessive blood loss are associated with a higher incidence of postoperative complications, aligning with conclusions from existing literature [29], 30]. However, research on the relationship between surgical duration and recurrence remains limited. Our findings highlight the long-term impact of surgical duration on recurrence risk, emphasizing the importance of minimizing unnecessary surgical delays and optimizing procedural efficiency in clinical practice.

Notably, beyond intraoperative parameters such as temperature, overall functional status and frailty play a critical role in postoperative recovery. Recent evidence indicates that sarcopenia and functional measures (e.g., handgrip strength) are stronger predictors of hospital stay and recovery trajectory after abdominal surgery than chronological age alone [31], suggesting that frailty serves as an independent risk stratification marker for identifying high-risk patients. In this study, prolonged hospitalization in hypothermic patients may reflect not only the physiological effects of low temperature but also underlying functional decline and frailty. Hypothermia may further exacerbate physiological stress in frail individuals, delaying recovery. Future research should incorporate functional indicators such as grip strength and gait speed into perioperative assessments, alongside temperature and other parameters, to establish more comprehensive risk prediction models.

In this study, the relationship between intraoperative hypothermia and postoperative recurrence emerged as an unexpected but significant finding. Previous research has primarily focused on the impact of intraoperative hypothermia on postoperative infections and other complications, with limited discussion on its role in recurrence. Our findings reveal that hypothermia not only increases the incidence of postoperative complications but also significantly elevates the recurrence rate. A possible explanation is that hypothermia enhances the release of inflammatory cytokines, such as interleukins and tumor necrosis factor, leading to immune dysfunction. This, in turn, impairs wound healing and the effectiveness of hernia repair, ultimately increasing recurrence risk. These findings provide a new perspective on the long-term prognostic implications of intraoperative temperature management, particularly for elderly patients undergoing unilateral inguinal hernia repair. Although previous studies have explored the association between intraoperative hypothermia and immune response, this study further integrates inflammatory biomarkers, such as peripheral blood WBC and NLR, to demonstrate that hypothermia may exacerbate systemic inflammatory responses, promoting postoperative complications. This discovery has significant clinical implications for intraoperative temperature management, emphasizing that temperature control helps prevent short-term complications and may also play a crucial role in reducing postoperative recurrence.

The findings of this study have important implications for clinical practice. First, intraoperative temperature management should be prioritized, particularly in elderly patients, where hypothermia should be avoided whenever possible. Effective warming strategies should be implemented to maintain intraoperative temperature above 36.25 °C, as this is crucial for reducing postoperative complications, including surgical site infections, seromas, and recurrence. Surgical duration and blood loss should also be carefully controlled to minimize the risk of adverse postoperative outcomes. Prolonged surgical duration and excessive blood loss have been linked to higher complication rates, making it essential to maintain these factors within an optimal range. For high-risk patients, personalized intraoperative management strategies should be employed, considering factors such as patient physiology, age, and comorbidities to optimize surgical planning and postoperative outcomes. Beyond intraoperative temperature control, comprehensive preoperative assessment is critical in reducing complications. This is particularly important for elderly patients and those with underlying conditions, where individualized anesthesia, surgical planning, and postoperative care protocols should be established to enhance recovery and minimize the risk of complications.

This study has several limitations. As a retrospective analysis, intraoperative hypothermia was not the result of deliberate intervention but rather reflected routine clinical practice, since active warming devices (e.g., Bair Hugger) were not regularly applied in general surgery at this institution due to workflow and cost constraints, particularly in shorter or lower-risk procedures. Consequently, the hypothermia group mainly represented unplanned events, which may have introduced selection bias and residual confounding. The relatively limited sample size and heterogeneity in case types may also restrict the generalizability of the findings. In addition, potential confounders such as comorbidity burden, frailty, and nutritional status were not systematically quantified. Although adjustments were made for age and sex, the absence of standardized indices such as the Charlson Comorbidity Index, frailty scales, or nutritional screening tools limited interpretability. Finally, although all operations were performed by experienced attending surgeons using standardized Lichtenstein repair, variations in surgical technique and operator experience could have influenced outcomes.

Future research should adopt large-scale, multicenter prospective designs with more comprehensive baseline assessments, incorporating comorbidities, frailty status, nutritional indicators, and surgeon-related variables to enhance robustness and generalizability. Intraoperative temperature management represents a critical area for refinement, with dynamic monitoring and precise control technologies offering potential to improve prognosis. Beyond temperature, perioperative factors such as anesthetic strategy, oxygenation, and fluid management also warrant systematic evaluation, with the aim of constructing integrated risk prediction models and advancing perioperative care for unilateral inguinal hernia repair toward greater precision and individualization.

Conclusions

This study conducted a retrospective analysis of clinical data from patients undergoing unilateral inguinal hernia repair to investigate the impact of intraoperative temperature and other surgical factors on postoperative complications and recurrence. The findings reveal that intraoperative hypothermia is closely associated with an increased risk of postoperative recurrence, while prolonged surgical duration and excessive blood loss significantly elevate the incidence of postoperative complications. Additionally, fluctuations in intraoperative temperature have a notable effect on postoperative wound infections and other complications, providing essential theoretical and data-driven support for optimizing unilateral inguinal hernia repair in clinical practice. The scientific significance of this study lies in its elucidation of the specific effects of intraoperative temperature, surgical duration, and blood loss on postoperative outcomes in unilateral inguinal hernia repair. Furthermore, it offers a novel perspective and foundation for future research on the relationship between these intraoperative factors, postoperative recurrence, and complications (Figure 5). From a clinical standpoint, optimizing intraoperative management – particularly temperature regulation – may effectively reduce postoperative complications and recurrence rates. Enhancing intraoperative temperature control could improve surgical outcomes and facilitate patient recovery.

Figure 5:

Impact of intraoperative temperature, surgical duration, and blood loss on postoperative complications and recurrence following unilateral inguinal hernia repair.

Corresponding author: Min Zhang, The Operating Room, The Affiliated Hospital of Southwest Medical University, No. 25, Taiping Street, Jiangyang District, 646100, Luzhou, Sichuan, Province, China, E-mail: 15196074394@163.com

Funding information: None.
Author contribution: Xiawei Zheng contributed to data collection, statistical analysis, and drafting of the manuscript. Min Zhang conceived and designed the study, supervised data interpretation, and critically revised the manuscript for important intellectual content. Both authors approved the final version of the manuscript and agree to be accountable for all aspects of the work.
Conflict of interest: The author declares no conflict of interest.
Data availability statement: All data can be provided as needed.

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Supplementary Material

This article contains supplementary material (https://doi.org/10.1515/med-2025-1324).

Received: 2025-03-18

Accepted: 2025-10-16

Published Online: 2025-12-17

This work is licensed under the Creative Commons Attribution 4.0 International License.

Supplementary Material

Articles in the same Issue

https://doi.org/10.1515/med-2025-1324

Keywords for this article

unilateral inguinal herni repair; intraoperative temperature; postoperative complications; recurrence; elderly patients

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