Role of transversus abdominis plane block combined with multimodal analgesia in early recovery after radical colorectal cancer surgery

Abstract

BACKGROUND

Colorectal cancer remains a leading cause of cancer-related morbidity and mortality worldwide. Despite advancements in laparoscopic surgical techniques, 30%-40% of patients experience moderate-to-severe postoperative pain, which can impede recovery and increase complications. Within the enhanced recovery after surgery (ERAS) framework, multimodal analgesia is essential for optimal pain management. Transversus abdominis plane (TAP) block, a regional anesthetic technique providing prolonged abdominal analgesia, has shown promise in abdominal surgeries. However, its role in enhancing multimodal analgesia and facilitating early recovery after radical colorectal cancer surgery remains inadequately investigated.

AIM

To investigate multiple clinical parameters in patients undergoing laparoscopic radical colorectal cancer surgery, specifically examining pain control effectiveness, markers of early postoperative recovery, physiological stress indicators, and treatment safety profile when ultrasound-guided TAP block was incorporated into multimodal analgesic protocols.

METHODS

Clinical records of 117 laparoscopic radical colorectal cancer surgery patients treated at our institution between December 2022 and December 2024 underwent retrospective examination. Patient allocation into study arms was determined by their postoperative pain management protocol: 59 patients constituted the observation arm (TAP block integrated with multimodal analgesia), while 58 patients formed the control arm (standard multimodal analgesia approach). The observation arm protocol involved a bilateral TAP block performed under ultrasound guidance during general anesthesia, administering 0.375% ropivacaine (20 mL per side), supplemented with postoperative patient-controlled intravenous analgesia (PCIA) and oral celecoxib administration. The control arm received an identical regimen minus the TAP block component. Comparative analysis encompassed Visual Analog Scale (VAS) pain measurements across multiple postoperative intervals, analgesic medication requirements, recovery milestone timings (initial ambulation, bowel function return, oral intake resumption), inflammatory and stress biomarkers [interleukin-6 (IL-6), C-reactive protein (CRP), cortisol (Cor) concentrations], Quality of Recovery-15 (QoR-15) assessment scores, adverse event profiles, and complication frequencies.

RESULTS

Pain intensity measurements using VAS methodology demonstrated significantly lower values in the observation cohort compared to controls at all assessment points (6 hours, 12 hours, 24 hours, 48 hours, and 72 hours postoperatively) during both rest and activity (P < 0.001). Within the initial 72-hour postoperative period, the observation group demonstrated reduced PCIA pump activation frequency, diminished total sufentanil consumption, lower rescue analgesia requirement rate (10.2% vs 31.0%), and superior patient satisfaction ratings regarding pain control (P < 0.05). Recovery milestones were achieved earlier in the observation cohort, with shorter intervals to first ambulation, initial flatus passage, and first oral intake compared to the control cohort (P < 0.001). Inflammatory and stress biomarker analysis revealed lower serum concentrations of IL-6, CRP, and Cor in the observation group on both postoperative day 1 and day 3 (P < 0.001). Recovery quality assessment using QoR-15 scoring demonstrated higher values in the observation group at both 24-hour and 48-hour postoperative evaluations (P < 0.001). The observation cohort experienced reduced severity of nausea/vomiting symptoms and lower frequencies of dizziness and somnolence compared to controls (P < 0.05). No statistically significant inter-group differences emerged regarding urinary retention incidence, pruritus occurrence, or postoperative complication rates (P > 0.05). Neither study group experienced respiratory depression events.

CONCLUSION

Ultrasound-guided TAP block combined with multimodal analgesia applied after laparoscopic radical colorectal cancer surgery can provide excellent analgesic effects, reduce opioid consumption, promote early ambulation and gastrointestinal function recovery, reduce postoperative stress response, improve recovery quality, reduce opioid-related adverse reactions, and has good safety, which is helpful in achieving ERAS goals.

Key Words: Transversus abdominis plane block; Multimodal analgesia; Colorectal cancer; Enhanced recovery after surgery; Postoperative pain; Ultrasound guidance

Core Tip: This retrospective study evaluates whether integrating an ultrasound-guided transversus abdominis plane (TAP) block into multimodal analgesia can further enhance postoperative recovery after laparoscopic radical colorectal cancer surgery. The findings show that TAP block significantly improves pain control, reduces opioid consumption, accelerates gastrointestinal and functional recovery, attenuates stress responses, and enhances early quality-of-recovery outcomes without increasing complications. These results provide important clinical evidence supporting optimized analgesic strategies and enhanced recovery after surgery implementation for colorectal cancer patients.

INTRODUCTION

Among malignant neoplasms worldwide, colorectal cancer represents a highly prevalent condition, with its incidence and mortality figures ranking prominently in cancer statistics[1]. Radical surgical excision remains the definitive therapeutic intervention for colorectal malignancies. Laparoscopic techniques have evolved to become the preferred surgical methodology for radical colorectal cancer resection, offering benefits including reduced surgical trauma and expedited convalescence[2]. Despite these advances, moderate-to-severe postoperative pain afflicts 30%-40% of patients, creating discomfort while potentially triggering amplified stress responses, compromised immune function, delayed recovery trajectories, and elevated complication risks[3].

The enhanced recovery after surgery (ERAS) framework prioritizes comprehensive perioperative care optimization, positioning effective postoperative analgesia as a fundamental component[4]. Through synergistic application of analgesic agents and techniques operating via distinct mechanisms, multimodal analgesia achieves enhanced pain relief while simultaneously reducing opioid requirements, establishing itself as the reference standard for postoperative pain control strategies[5]. As a regional anesthetic technique, transversus abdominis plane (TAP) block delivers prolonged abdominal wall analgesia by infiltrating local anesthetic agents into the TAP, effectively interrupting signal transmission through the anterior branches of spinal nerves T7-L1[6]. Contemporary research has demonstrated TAP block's analgesic value in abdominal surgical procedures; however, insufficient investigation exists regarding its potential to further refine multimodal analgesic protocols and facilitate early recovery following radical colorectal cancer operations[7]. Furthermore, TAP block’s influence on postoperative stress physiology and recovery quality metrics requires additional clinical substantiation[8].

Consequently, this investigation employed retrospective methodology to evaluate pain control effectiveness, early recovery parameters, stress response characteristics, and safety considerations associated with ultrasound-guided TAP block integration into multimodal analgesia protocols following laparoscopic radical colorectal cancer surgery. The objective was generating clinical evidence to support perioperative pain management optimization and enhanced recovery facilitation in the colorectal cancer patient population.

Therefore, this study aims to evaluate the analgesic efficacy, early recovery indicators, stress response, and safety of ultrasound-guided TAP block combined with multimodal analgesia after laparoscopic radical colorectal cancer surgery through retrospective analysis, providing clinical evidence for optimizing perioperative pain management and promoting rapid recovery in colorectal cancer patients.

MATERIALS AND METHODS

Study subjects

This study retrospectively analyzed clinical data from 132 patients who underwent radical colorectal cancer surgery at our hospital from December 2022 to December 2024. This study was approved by the hospital ethics committee. As the study was a retrospective analysis, the ethics committee approved exemption from patient informed consent.

Inclusion criteria: (1) Age 18-75 years; (2) Pathologically confirmed colorectal cancer meeting indications for radical surgery; (3) American Society of Anesthesiologists (ASA) physical status classification grade I-III; (4) Body mass index (BMI) 18-30 kg/m²; (5) Underwent laparoscopic radical colorectal cancer surgery; and (6) Complete clinical data.

Exclusion criteria: (1) Severe cardiac, pulmonary, hepatic, or renal dysfunction; (2) Coagulation disorders or long-term use of anticoagulant drugs; (3) Infection or deformity at the puncture site; (4) Allergy to local anesthetics or study-related drugs; (5) Long-term use of opioids or history of drug abuse; (6) Mental illness or cognitive impairment, unable to cooperate with pain assessment; (7) Intraoperative changes in surgical approach or conversion to open surgery; (8) Severe postoperative complications requiring reoperation, or withdrawal from ERAS management protocol for various reasons postoperatively; and (9) Missing key data such as pain assessment and laboratory examinations.

According to the above criteria, 117 patients were finally included for analysis. Based on different postoperative analgesia protocols, the 117 patients were divided into two groups: (1) Observation group (n = 59): TAP block combined with multimodal analgesia; and (2) Control group (n = 58): Conventional multimodal analgesia.

Grouping method and surgical approach

A single surgical team performed all laparoscopic radical colorectal cancer operations, adhering to established oncological principles including adequate bowel resection margins and regional lymph node dissection. Surgical procedures encompassed right hemicolectomy, left hemicolectomy, sigmoid colectomy, anterior rectal resection, or abdominoperineal resection, selected according to tumor anatomical location. Four to five trocar sites were utilized, with primary ports measuring 10-12 mm diameter and accessory ports measuring 5 mm diameter.

Postoperative management incorporated all patients into ERAS protocols, featuring early mobilization, early oral feeding, and avoidance of routine nasogastric decompression and abdominal drainage.

Group assignment was determined through review of anesthesia documentation and postoperative analgesia orders. Observation group patients received intraoperative ultrasound-guided bilateral TAP block combined with multimodal analgesia; control group patients received exclusively conventional multimodal analgesia.

Anesthesia and analgesia methods

General anesthesia was administered to all patients following preoperative fasting periods of 8-12 hours for solids and 2-4 hours for liquids. Upon operating room arrival, peripheral venous access was secured and standard monitoring established [electrocardiogram; blood pressure; heart rate; saturation of peripheral oxygen (SpO₂)]. Anesthetic induction consisted of midazolam 0.05 mg/kg, sufentanil 0.3-0.5 μg/kg, etomidate 0.2-0.3 mg/kg, and cisatracurium 0.15-0.2 mg/kg, followed by endotracheal intubation and mechanical ventilation initiation. Anesthetic maintenance utilized continuous intravenous infusions of propofol 4-8 mg/(kg/hour) and remifentanil 0.1-0.3 μg/(kg/minute), with intermittent cisatracurium supplementation. Anesthetic agent dosing was titrated according to intraoperative hemodynamic fluctuations to ensure circulatory stability.

Control cohort protocol: Both groups received intravenous flurbiprofen axetil 50 mg administered thirty minutes before surgical completion. Postoperative analgesia employed patient-controlled intravenous analgesia (PCIA): Sufentanil 100 μg + ondansetron 12 mg diluted with normal saline to 100 mL total volume, programmed with 2 mL/hour continuous infusion, 0.5 mL bolus dose, and 15-minute lockout interval. Oral celecoxib 200 mg was administered routinely twice daily postoperatively.

Observation cohort protocol: In addition to all interventions in the control protocol, ultrasound-guided bilateral TAP block was incorporated. Per anesthesia documentation, while patients remained under general anesthesia prior to surgical conclusion, a high-frequency linear transducer (6-13 MHz) was positioned at the mid-axillary line/iliac crest intersection to visualize the three muscular layers: External oblique, internal oblique, and transversus abdominis muscles. Under continuous ultrasound visualization utilizing in-plane technique, a 22G needle was advanced into the TAP between internal oblique and transversus abdominis muscles. Following negative aspiration confirmation for blood and air, 0.375% ropivacaine 20 mL was deposited on each side (total volume 40 mL, total ropivacaine dose 150 mg; all patients weighed ≥ 50 kg, ensuring ropivacaine dosing ≤ 3 mg/kg), with observation of homogeneous medication spread within the TAP. Postoperative analgesia protocols matched the control cohort.

If patients had Visual Analog Scale (VAS) scores > 4 postoperatively, rescue analgesia was administered: Intramuscular injection of tramadol 100 mg or intravenous injection of flurbiprofen axetil 50 mg, which could be repeated if necessary, with an interval of ≥ 6 hours between administrations.

Observation indicators

General data: Baseline data of patients in both groups were recorded through the electronic medical record system, including: Gender, age, BMI, ASA physical status classification, tumor location (colon/rectum), tumor, node, and metastasis (TNM) staging, operative time, intraoperative blood loss, and surgical approach.

Primary observation indicators: VAS scores at rest and during movement were collected by reviewing nursing records and pain assessment forms: A 0-10 points scale was used to assess pain severity at rest and during movement (coughing) at 6 hours, 12 hours, 24 hours, 48 hours, and 72 hours postoperatively, with 0 being no pain and 10 being severe pain. VAS scores were assessed by trained nurses who were blinded to patient grouping.

Secondary observation indicators: Analgesia-related indicators: The number of effective PCIA pump presses within 72 hours postoperatively and cumulative sufentanil consumption (μg) at 72 hours postoperatively were recorded. A 5-point scale was used to assess analgesia satisfaction at 48 hours postoperatively through patient satisfaction questionnaires, with 1 being very dissatisfied and 5 being very satisfied. The incidence of rescue analgesia was recorded, defined as the proportion of patients requiring additional analgesic medication due to VAS scores > 4 within 72 hours postoperatively.

Early recovery indicators: Time to first ambulation (time from end of surgery to patient’s first standing or walking from bed), time to first flatus (time from end of surgery to patient’s first spontaneous flatus), and time to first oral intake (time from end of surgery to patient's first liquid diet intake) were recorded, all in hours.

Stress response indicators: Serum interleukin-6 (IL-6), C-reactive protein (CRP), and cortisol (Cor) levels were collected by reviewing laboratory report systems for peripheral venous blood samples collected fasting in the morning on preoperative day 1 and postoperative days 1 and 3. The above indicators were all tested by enzyme-linked immunosorbent assay in the hospital laboratory.

Postoperative adverse reactions: The occurrence and severity of adverse reactions including nausea and vomiting, urinary retention, skin itching, respiratory depression (respiratory rate < 8 breaths/min or SpO₂ < 90%), and dizziness and drowsiness within 72 hours postoperatively were recorded. Nausea and vomiting grading: Grade 0 for no nausea or vomiting, grade I for mild nausea, grade II for nausea with 1-2 episodes of vomiting, grade III for frequent vomiting ≥ 3 episodes.

Postoperative recovery quality: The Quality of Recovery-15 (QoR-15) scale was used to assess patient recovery quality at 24 hours and 48 hours postoperatively. This scale contains 15 items with a total score of 0-150 points, with higher scores indicating better recovery quality. This scale data was collected by trained researchers through review of nursing records or telephone follow-up.

Postoperative complications: The occurrence of complications including wound infection, pulmonary infection, anastomotic leakage, and intestinal obstruction within 30 days postoperatively was recorded, and complication severity was assessed using the Clavien-Dindo classification system.

Statistical analysis

SPSS 26.0 statistical software was used for data analysis. Continuous variables were first tested for normality (Shapiro-Wilk test) and homogeneity of variance (Levene’s test). Continuous variables conforming to normal distribution were expressed as mean ± SD, and independent samples t-test was used for comparison between groups; continuous variables not conforming to normal distribution were expressed as median interquartile range (IQR) [M (Q1, Q3)], and Mann-Whitney U test was used for comparison between groups. For variables, normality testing confirmed that “effective PCIA pump presses” showed non-normal distribution (P = 0.038 in observation group); therefore, this variable was re-analyzed using Mann-Whitney U test and presented as median (IQR). Other continuous variables passed normality testing (P > 0.05) and were appropriately analyzed using parametric tests. Categorical variables were expressed as n (%), and χ² test or Fisher’s exact test (when theoretical frequency < 5) was used for comparison between groups. Mann-Whitney U test was used for ordinal data. Bonferroni method was used for multiple comparison correction of data measured at multiple time points. All tests were two-sided, with P < 0.05 considered statistically significant.

RESULTS

Comparison of general data between two groups

There were no statistically significant differences between the two groups in gender, age, BMI, ASA physical status classification, tumor location, tumor TNM staging, operative time, intraoperative blood loss, and surgical approach (P > 0.05), indicating comparability (Table 1).

Table 1 Comparison of general data between two groups, n (%).

Item	Observation group (n = 59)	Control group (n = 58)	Statistic	P value
Gender			χ2 = 0.145	0.703
Male	35 (59.3)	33 (56.9)
Female	24 (40.7)	25 (43.1)
Age (years, mean ± SD)	58.6 ± 10.2	59.3 ± 9.8	t = 0.389	0.698
BMI (kg/m2, mean ± SD)	23.4 ± 2.8	23.7 ± 2.6	t = 0.618	0.538
ASA classification			Z = -0.326	0.744
Grade I	18 (30.5)	16 (27.6)
Grade II	32 (54.2)	34 (58.6)
Grade III	9 (15.3)	8 (13.8)
Tumor location			χ2 = 0.069	0.793
Colon	37 (62.7)	35 (60.3)
Rectum	22 (37.3)	23 (39.7)
TNM staging			Z = -0.158	0.875
Stage I	12 (20.3)	11 (19.0)
Stage II	26 (44.1)	27 (46.6)
Stage III	21 (35.6)	20 (34.4)
Surgical approach			χ2 = 0.892	0.926
Right hemicolectomy	19 (32.2)	17 (29.3)
Left hemicolectomy	11 (18.6)	13 (22.4)
Sigmoid colectomy	7 (11.9)	5 (8.6)
Anterior rectal resection	18 (30.5)	19 (32.8)
Abdominoperineal resection	4 (6.8)	4 (6.9)
Operative time (minute, mean ± SD)	186.4 ± 35.7	189.2 ± 38.1	t = 0.415	0.679
Intraoperative blood loss (mL, mean ± SD)	82.3 ± 28.6	85.7 ± 31.2	t = 0.622	0.535

BMI: Body mass index; ASA: American Society of Anesthesiologist; TNM: Tumor, node, and metastasis.

Comparison of VAS scores at different postoperative time points between two groups

VAS scores at rest and during movement at all postoperative time points were lower in the observation group than in the control group. Bonferroni method was applied for multiple comparison correction of data from 5 time points (corrected significance level α = 0.01), and P values at all time points were < 0.001, with differences remaining statistically significant after correction (Table 2 and Figure 1).

Figure 1 Comparison of postoperative Visual Analog Scale pain scores between observation and control groups at different time points. A: Postoperative Visual Analog Scale (VAS) pain scores in observation groups; B: Postoperative VAS pain scores in control groups. The graph illustrates VAS pain scores at 6, 12, 24, 48, and 72 hours postoperatively. The blue line represents the observation group (TAP block combined with multimodal analgesia), while the red line represents the control group (multimodal analgesia alone). Data are presented as mean ± SD. The observation group demonstrated consistently lower VAS scores compared to the control group across all time points, with both groups showing a declining trend in pain intensity over time. VAS: Visual Analog Scale; TAP: Transversus abdominis plane.

Table 2 Comparison of Visual Analog Scale scores at different postoperative time points between two groups (points, mean ± SD).

Time point	Resting VAS score			Movement VAS score
	Observation group (n = 59)	Control group (n = 58)	P value	Observation group (n = 59)	Control group (n = 58)	P value
Postop 6 hours	2.1 ± 0.8	3.4 ± 1.1	< 0.001	3.5 ± 1.0	4.9 ± 1.3	< 0.001
Postop 12 hours	1.8 ± 0.7	2.9 ± 0.9	< 0.001	3.1 ± 0.9	4.3 ± 1.1	< 0.001
Postop 24 hours	1.5 ± 0.6	2.4 ± 0.8	< 0.001	2.7 ± 0.8	3.7 ± 1.0	< 0.001
Postop 48 hours	1.2 ± 0.5	1.9 ± 0.7	< 0.001	2.2 ± 0.7	3.1 ± 0.9	< 0.001
Postop 72 hours	1.0 ± 0.4	1.5 ± 0.6	< 0.001	1.8 ± 0.6	2.5 ± 0.8	< 0.001

Bonferroni method was used for multiple comparison correction, with corrected significance level α = 0.01; indicates P < 0.001, remaining statistically significant after correction.

VAS: Visual Analog Scale.

Comparison of analgesia-related indicators between two groups

The observation group had fewer effective PCIA pump presses within 72 hours postoperatively, lower cumulative sufentanil consumption at 72 hours postoperatively, and lower rescue analgesia incidence rate compared with the control group (P < 0.05), and higher analgesia satisfaction scores at 48 hours postoperatively than the control group (P < 0.05) (Table 3). Cumulative sufentanil consumption at 72 hours postoperatively included the sum of PCIA pump background infusion and patient-controlled bolus doses. PCIA pumps were replaced with new pumps after drug depletion at 48-50 hours postoperatively to ensure continuous analgesia. For patients requiring rescue analgesia, this mainly occurred when VAS scores during movement were > 4 within 6-24 hours postoperatively.

Table 3 Comparison of analgesia-related indicators between two groups.

Indicator	Observation group (n = 59)	Control group (n = 58)	Statistic	P value
Effective PCIA pump presses [times, M (Q1, Q3)]	8.0 (6.0, 10.0)	14.0 (11.0, 18.0)	Z = -6.825	< 0.001
Cumulative sufentanil at 72 hours postop (μg, mean ± SD)	68.5 ± 15.3	89.7 ± 18.6	t = 6.842	< 0.001
Analgesia satisfaction score (points, mean ± SD)	4.3 ± 0.6	3.7 ± 0.7	t = 5.025	< 0.001
Rescue analgesia incidence rate, n (%)	6 (10.2)	18 (31.0)	χ2 = 7.783	0.005

PCIA: Patient-controlled intravenous analgesia.

Comparison of early recovery indicators between two groups

Time to first ambulation (defined as the time for patients to stand from bed and walk ≥ 3 meters postoperatively), time to first flatus, and time to first oral intake (defined as the time for patients to consume ≥ 100 mL liquid diet postoperatively) were shorter in the observation group than in the control group (P < 0.05) (Table 4).

Table 4 Comparison of early recovery indicators between two groups (hour, mean ± SD).

Indicator	Observation group (n = 59)	Control group (n = 58)	t value	P value
Time to first ambulation	18.6 ± 4.3	24.8 ± 5.7	6.731	< 0.001
Time to first flatus	42.3 ± 10.8	56.7 ± 13.4	6.475	< 0.001
Time to first oral Intake	16.2 ± 3.8	21.5 ± 5.2	6.332	< 0.001

Comparison of stress response indicators between two groups

There were no statistically significant differences in stress response indicators on preoperative day 1 between the two groups (P > 0.05). Serum IL-6, CRP, and Cor levels on postoperative days 1 and 3 were elevated compared with preoperative levels in both groups. Bonferroni method was applied for comparison correction of 3 time points for each stress indicator (corrected significance level α = 0.017), and all indicator levels on postoperative days 1 and 3 were lower in the observation group than in the control group, with differences remaining statistically significant after correction (Table 5).

Table 5 Comparison of stress response indicators between two groups (mean ± SD).

Indicator	Time point	Observation group (n = 59)	Control group (n = 58)	t value	P value	After correction
IL-6 (pg/mL)	Preop day 1	12.8 ± 3.6	13.1 ± 3.8	0.447	0.656	NS
	Postop day 1	86.5 ± 18.4	112.3 ± 22.6	6.878	< 0.001	P < 0.001
	Postop day 3	45.2 ± 12.7	63.8 ± 15.3	7.256	< 0.001	P < 0.001
CRP (mg/L)	Preop day 1	5.2 ± 1.8	5.4 ± 1.9	0.588	0.558	NS
	Postop day 1	68.4 ± 15.2	89.6 ± 18.9	6.898	< 0.001	P < 0.001
	Postop day 3	38.7 ± 10.5	54.3 ± 13.8	6.95	< 0.001	P < 0.001
Cor (nmol/L)	Preop day 1	285.3 ± 45.6	289.7 ± 48.2	0.517	0.606	NS
	Postop day 1	486.8 ± 68.4	562.5 ± 82.3	5.538	< 0.001	P < 0.001
	Postop day 3	368.2 ± 52.7	428.6 ± 64.5	5.685	< 0.001	P < 0.001

Bonferroni method was used for multiple comparison correction of 3 time points for each indicator, with corrected significance level α = 0.017. NS indicates not statistically significant (P > 0.05). P < 0.001 after correction indicates remaining statistically significant after correction. IL-6: Interleukin-6; CRP: C-reactive protein; Cor: Cortisol.

Comparison of postoperative adverse reactions between two groups

The severity of nausea and vomiting (assessed using 4-grade classification) and the incidence of dizziness and drowsiness were lower in the observation group than in the control group (P < 0.05), while there were no statistically significant differences in the incidence of urinary retention and skin itching between the two groups (P > 0.05). No respiratory depression occurred in either group (Table 6).

Table 6 Comparison of postoperative adverse reactions between two groups, n (%).

Adverse reaction	Observation group (n = 59)	Control group (n = 58)	Statistic	P value
Nausea and vomiting			Z = -2.534	0.011
Grade 0	45 (76.3)	32 (55.2)
Grade I	11 (18.6)	17 (29.3)
Grade II	3 (5.1)	7 (12.1)
Grade III	0 (0)	2 (3.4)
Urinary retention	3 (5.1)	6 (10.3)	Fisher’s exact test	0.312
Skin itching	2 (3.4)	4 (6.9)	Fisher’s exact test	0.431
Respiratory depression	0 (0)	0 (0)	-	-
Dizziness and drowsiness	8 (13.6)	18 (31.0)	χ2 = 5.123	0.024

Comparison of postoperative recovery quality scores between two groups

QoR-15 scores at 24 hours and 48 hours postoperatively were higher in the observation group than in the control group. Bonferroni method was applied for multiple comparison correction of data from 2 time points (corrected significance level α = 0.025), with differences remaining statistically significant after correction (Table 7).

Table 7 Comparison of postoperative recovery quality scores between two groups (points, mean ± SD).

Time point	Observation group (n = 59)	Control group (n = 58)	t value	P value	After correction
Postop 24 hours	108.6 ± 12.4	95.3 ± 14.7	5.436	< 0.001	P < 0.001
Postop 48 hours	122.5 ± 11.8	110.2 ± 13.5	5.389	< 0.001	P < 0.001

Bonferroni method was used for multiple comparison correction of 2 time points, with corrected significance level α = 0.025. P < 0.001 after correction indicates remaining statistically significant after correction.

Comparison of postoperative complications between two groups

There were no statistically significant differences in the incidence of complications including wound infection, pulmonary infection, anastomotic leakage, and intestinal obstruction within 30 days postoperatively between the two groups (P > 0.05). There was no statistically significant difference in Clavien-Dindo classification of complications between the two groups (P > 0.05) (Table 8).

Table 8 Comparison of postoperative complications between two groups, n (%).

Complication	Observation group (n = 59)	Control group (n = 58)	Statistic	P value
Wound infection	2 (3.4)	3 (5.2)	Fisher’s exact test	0.677
Pulmonary infection	3 (5.1)	5 (8.6)	Fisher’s exact test	0.492
Anastomotic leakage	1 (1.7)	2 (3.4)	Fisher’s exact test	0.617
Intestinal obstruction	2 (3.4)	3 (5.2)	Fisher’s exact test	0.677
Total incidence	8 (13.6)	13 (22.4)	χ2 = 1.541	0.214
Clavien-Dindo classification			Z = -0.985	0.325
Grade I	4 (6.8)	5 (8.6)
Grade II	3 (5.1)	6 (10.3)
Grade IIIa	1 (1.7)	2 (3.4)
Grade IIIb and above	0 (0)	0 (0)

DISCUSSION

This study demonstrates an integrated mechanistic pathway by which TAP block enhances ERAS outcomes in colorectal cancer surgery: Superior pain control enables earlier mobilization and feeding, which in turn reduces opioid requirements and attenuates the surgical stress response, ultimately improving recovery quality. Our findings align with and extend previous literature. Comparable analgesic efficacy between TAP block combined with multimodal analgesia vs epidural analgesia in laparoscopic colon cancer surgery, supporting TAP block as a viable regional technique. However, our study uniquely demonstrates TAP block’s impact on stress biomarkers (IL-6, CRP, Cor) and QoR-15 scores, outcomes not systematically evaluated and confirmed TAP block’s opioid-sparing benefits in bariatric surgery, consistent with our 23.6% reduction in sufentanil consumption. Building on this foundation, we demonstrate that this opioid-sparing effect translates to accelerated gastrointestinal recovery (14-hour earlier flatus) and reduced stress response-mechanistic links not established in the bariatric population. Most notably, recently examined multimodal analgesia in elderly colorectal cancer patients but did not specifically evaluate TAP block’s incremental contribution. Our controlled comparison isolates TAP block’s specific effects within a multimodal framework, demonstrating clear additional benefits beyond systemic analgesia alone.

TAP block provides effective sensory blockade for the anterolateral abdominal wall by injecting local anesthetics in the fascial plane between the internal oblique muscle and transversus abdominis muscle, blocking the anterior branches of T7-L1 spinal nerves[9]. This study used bilateral TAP block with 20 mL of 0.375% ropivacaine injected on each side, totaling 150 mg, which ensured both the range and duration of blockade while remaining within safe dosage limits[10]. Results showed that VAS scores at all postoperative time points were significantly lower in the observation group than in the control group, especially the analgesic effect during movement was more prominent, which is closely related to TAP block’s effective blockade of somatic nerve conduction in the abdominal wall, reducing pain caused by incision and abdominal wall traction[11].

It is worth noting that the analgesic effect of TAP block in this study lasted until 72 hours postoperatively, which may be related to the pharmacokinetic characteristics of ropivacaine and the anatomical features of the TAP. Studies have shown that ropivacaine is absorbed slowly in the TAP and can maintain local anesthetic effects for an extended period[12]. In addition, TAP block mainly blocks somatic pain conduction and has limited effects on visceral pain, so it needs to be combined with systemic analgesic drugs to achieve optimal analgesic effects[13].

Multimodal analgesia is a core element of ERAS. Through the combined application of analgesic techniques and drugs with different mechanisms of action, it can block pain conduction pathways at different levels, producing synergistic and additive effects[14]. The multimodal analgesia protocol in this study included TAP block, PCIA (sufentanil), and non-steroidal anti-inflammatory drugs (celecoxib, flurbiprofen axetil), acting at different levels including peripheral, spinal, and central, forming a complete analgesic system[15].

Study results showed that cumulative sufentanil consumption at 72 hours postoperatively was reduced by 23.6% in the observation group compared with the control group, effective PCIA pump presses were reduced by 43.2%, and rescue analgesia incidence rate was reduced by 67.1%. This indicates that the addition of TAP block significantly reduced opioid demand and reduced the risk of opioid-related adverse reactions[16]. In this study, both the severity of nausea and vomiting and the incidence of dizziness and drowsiness were lower in the observation group than in the control group, further confirming the clinical value of reducing opioid consumption. This opioid-sparing effect not only improves patient comfort but also helps reduce opioid-induced intestinal dysfunction and promotes gastrointestinal function recovery[17].

Effective postoperative analgesia is a prerequisite for achieving rapid recovery. Pain not only affects patient comfort but may also lead patients to reduce activity and delay feeding due to pain, thereby affecting the recovery process[18]. This study showed that time to first ambulation, time to first flatus, and time to first oral intake were all significantly earlier in the observation group than in the control group, which is closely related to the excellent analgesic effect provided by TAP block.

Early ambulation can reduce the risk of postoperative deep vein thrombosis and pulmonary complications and promote gastrointestinal function recovery[19]. In this study, patients in the observation group were able to ambulate an average of 18.6 hours postoperatively, approximately 6 hours earlier than the control group, a difference that is clinically significant. Early mobilization requires patients to tolerate pain during movement, and study results showed that movement VAS scores were significantly lower in the observation group than in the control group, providing guarantee for early mobilization[20].

Time to first flatus is an important indicator reflecting gastrointestinal function recovery. Studies showed that time to first flatus was approximately 14 hours earlier in the observation group than in the control group. This may be related to the following mechanisms: First, TAP block reduced opioid consumption, reducing the inhibitory effect of opioids on the intestine[21]; second, good analgesic effects promoted early mobilization and feeding, promoting intestinal motility through mechanical stimulation; in addition, reducing pain stress response also helps reduce sympathetic nervous tension and improve intestinal blood supply and function[22].

Surgical trauma can cause the body to produce stress responses, manifested as proinflammatory cytokine release, acute phase reactant protein elevation, and hypothalamic-pituitary-adrenal axis activation[23]. Excessive stress response may lead to immune function suppression and enhanced catabolism, which is unfavorable for postoperative recovery. This study measured three stress response indicators: IL-6, CRP, and Cor, and results showed that all indicator levels on postoperative days 1 and 3 were significantly lower in the observation group than in the control group.

IL-6 is an important proinflammatory cytokine, and its level is related to the degree of surgical trauma and risk of postoperative complications[24]. CRP is an acute phase reactant protein synthesized by the liver, regulated by cytokines such as IL-6, and is a sensitive indicator reflecting systemic inflammatory response[25]. Cor is a key hormone in stress response, and its elevated level reflects the degree of hypothalamic-pituitary-adrenal axis activation[26]. TAP block combined with multimodal analgesia in this study was able to reduce these stress response indicators, which may be related to the following mechanisms: First, effective analgesia reduced neuroendocrine responses caused by nociceptive stimulation; second, reducing opioid consumption may have reduced the immunosuppressive effects of the drugs themselves; in addition, early mobilization and feeding also help regulate stress response and promote immune function recovery[27,28].

The QoR-15 scale is an effective tool for assessing postoperative recovery quality, covering five dimensions: Pain, physical comfort, psychological support, physical independence, and emotional state[29]. This study showed that QoR-15 scores at 24 hours and 48 hours postoperatively were significantly higher in the observation group than in the control group, indicating that TAP block combined with multimodal analgesia can comprehensively improve patients’ postoperative recovery experience. This improvement is reflected not only in pain control but also in multiple aspects including patients’ overall comfort, activity capacity, and psychological state, mutually corroborating the observed improvements in analgesic effects, reduced adverse reactions, and accelerated early recovery in this study[30].

In this study, there was no significant difference in postoperative complication incidence rates between the two groups, indicating that TAP block is safe when applied after radical colorectal cancer surgery. No serious TAP block-related complications such as local anesthetic toxicity or intra-abdominal organ injury occurred in the observation group, which benefited from the application of ultrasound-guided technology and strict operating protocols[31]. It is worth noting that the incidence of opioid-related adverse reactions such as nausea, vomiting, dizziness, and drowsiness was lower in the observation group than in the control group, further confirming the opioid-sparing effect of TAP block. No respiratory depression occurred in either group, indicating that the analgesia protocols in this study were within safe limits.

This study has the following limitations: First, as a retrospective study, there may be selection bias and information bias, and some confounding factors are difficult to completely control; second, this study was a single-center study with a relatively limited sample size, and the generalizability of results requires further verification; third, this study did not explore optimization of optimal local anesthetic concentration, volume, and timing for TAP block; fourth, this study had a short follow-up period and did not evaluate the impact of TAP block on long-term prognosis and chronic pain incidence; finally, this study did not conduct cost-benefit analysis, and the health economic value of TAP block requires further research[32].

CONCLUSION

Study results indicate that ultrasound-guided TAP block combined with multimodal analgesia after laparoscopic radical colorectal cancer surgery can provide excellent analgesic effects, reduce opioid consumption, promote early recovery, reduce stress response, improve recovery quality, and has good safety. This provides clinical evidence for optimizing perioperative pain management in colorectal cancer and improving ERAS implementation protocols. Future research could consider conducting multi-center, large-sample randomized controlled trials to further verify the efficacy of TAP block; exploring optimal implementation protocols for TAP block, including local anesthetic selection, timing of administration, and comparison of single vs continuous administration; evaluating the impact of TAP block on long-term prognosis, including chronic pain, tumor recurrence, and long-term survival; and conducting health economic evaluations to provide more comprehensive evidence support for clinical decision-making.