European Journal of Cardiovascular Medicine

Liver tumors, both primary such as hepatocellular carcinoma (HCC) and secondary like colorectal liver metastases, represent a significant global health burden, necessitating effective and precise surgical interventions for optimal outcomes (1,2). Surgical resection remains the cornerstone of curative treatment in eligible patients, but success heavily depends on the complete excision of tumor tissue with adequate margins while preserving sufficient functional liver parenchyma (3).

Preoperative imaging modalities, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), offer valuable insights into tumor characteristics and vascular anatomy; however, they often fall short in detecting small, deep-seated, or satellite lesions during surgery (4,5). Intraoperative ultrasound (IOUS), as a real-time imaging tool, has emerged as a valuable adjunct in liver surgery. It enhances the surgeon’s ability to visualize liver anatomy, locate non-palpable lesions, assess tumor-vessel relationships, and guide resection margins with greater accuracy (6,7).

Several studies have demonstrated that IOUS can alter surgical strategies in a significant number of cases by identifying previously undetected lesions and redefining resection boundaries (8,9). Moreover, its intraoperative utility contributes to reducing the risk of local recurrence and improving long-term survival outcomes (10). Despite advancements in image-guided surgery, the incorporation of IOUS into routine hepatic resection practices varies widely across institutions and is often dependent on the surgeon’s expertise and equipment availability.

This study aims to evaluate the impact of intraoperative ultrasound on surgical accuracy, margin clearance, and short-term clinical outcomes in patients undergoing liver tumor resection. By comparing outcomes with and without IOUS guidance, this research intends to provide evidence supporting its integration as a standard intraoperative tool in hepatic oncology surgery.

This prospective observational study was conducted over a period of 12 months in the Department of Surgery at a tertiary care center. The study included a total of 60 patients who were scheduled for elective liver tumor resection, either for primary liver tumors such as hepatocellular carcinoma or for secondary tumors such as colorectal liver metastases.

Inclusion   Criteria: Patients aged 18–75 years with radiologically confirmed resectable liver tumors, normal coagulation profiles, and adequate liver function (Child-Pugh A or B) were included in the study.

Exclusion Criteria: Patients with unresectable or diffuse metastatic disease, previous hepatic surgery, severe comorbidities, or contraindications for general anesthesia were excluded.

Study Design: Participants were divided into two groups of 30 patients each. Group A underwent liver resection with the assistance of intraoperative ultrasound (IOUS), while Group B underwent conventional liver resection without IOUS guidance. Allocation was non-randomized and based on the availability of intraoperative imaging equipment and expertise.

Preoperative Assessment: All patients underwent standard preoperative workup including liver function tests, tumor markers (AFP, CEA), contrast-enhanced CT or MRI of the liver, and cardiopulmonary evaluation for surgical fitness.

Intraoperative Protocol: In Group A, IOUS was performed using a high-frequency linear probe after liver mobilization and before parenchymal transection. The surgeon evaluated the number, size, location of lesions, and their proximity to vascular structures. Resection planes were modified accordingly. In Group B, resection was guided solely by preoperative imaging and intraoperative palpation.

Postoperative Follow-Up: Patients were monitored for surgical margins (confirmed by histopathology), postoperative complications (graded by Clavien-Dindo classification), and hospital stay. Imaging follow-up was done at 1 and 6 months postoperatively to assess recurrence.

Statistical Analysis: Data were analyzed using SPSS version 25. Continuous variables were expressed as mean ± standard deviation and compared using the Student's t-test. Categorical variables were analyzed using the Chi-square test or Fisher’s exact test. A p-value of <0.05 was considered statistically significant.

A total of 60 patients were enrolled in the study, with 30 patients in each group (Group A – IOUS-guided resection; Group B – conventional resection). The baseline demographic and clinical characteristics of both groups were comparable (Table 1).

Table 1: Baseline Demographic and Clinical Characteristics

IOUS altered the surgical plan in 12 patients (40%) in Group A by detecting additional lesions (n=8) and redefining tumor margins (n=4). The rate of R0 resections (negative surgical margins) was significantly higher in Group A compared to Group B (Table 2).

Table 2: Intraoperative and Oncologic Outcomes

Patients in Group A experienced fewer postoperative complications and had shorter hospital stays (Table 3). The incidence of early local recurrence within 6 months was also lower in the IOUS group.

Table 3: Postoperative Outcomes and Recurrence

*Statistically significant (p < 0.05)

In summary, patients undergoing IOUS-guided liver tumor resection showed improved surgical accuracy, better margin status, and reduced early recurrence rates compared to those who underwent resection without intraoperative imaging guidance (Tables 2 and 3).

This study highlights the clinical value of intraoperative ultrasound (IOUS) in improving the precision and effectiveness of liver tumor resections. Our findings demonstrate that IOUS significantly increases the rate of R0 resections, facilitates detection of additional lesions, and positively influences surgical decision-making—all of which contribute to better short-term outcomes.

IOUS has emerged as a critical intraoperative tool due to its ability to provide real-time imaging of hepatic structures and lesions during surgery. Unlike preoperative imaging modalities that can miss small, isodense, or deep-seated tumors, IOUS enhances intraoperative visualization and enables dynamic assessment of the tumor’s relation to vascular and biliary structures (1,2). In our study, additional lesions were detected in 26.7% of patients in the IOUS group, consistent with previous studies reporting detection rates of 20–35% for previously unrecognized nodules during surgery (3,4).

One of the most significant advantages of IOUS is its role in increasing the likelihood of complete tumor removal. Our results showed a significantly higher R0 resection rate in the IOUS group (93.3%) compared to the non-IOUS group (76.7%), supporting earlier findings that IOUS-guided resections correlate with better oncologic outcomes and reduced local recurrence (5,6). Complete resection is a well-established predictor of long-term survival in hepatic malignancies, making IOUS an indispensable tool in achieving curative outcomes (7).

Modifications in surgical planning occurred in 40% of cases in the IOUS group in this study. This is similar to the findings of Torzilli et al., who reported that IOUS altered the resection strategy in over one-third of their patients by uncovering satellite lesions or redefining tumor margins (8). Such real-time decision-making can significantly impact patient prognosis by avoiding inadequate resections or the need for reoperations (9,10).

Postoperative complications were also fewer in the IOUS group, although not statistically significant. However, the shorter hospital stay observed in our study aligns with other literature suggesting that more precise resections reduce the incidence of postoperative liver failure and surgical site infections (11,12). Furthermore, the lower recurrence rate at 6 months in the IOUS group, although not statistically significant in our sample, is consistent with previous reports indicating better long-term local control when IOUS is employed (13-15).

Another notable aspect is the ease of integration of IOUS into routine surgical practice, especially with modern portable ultrasound systems. Despite this, IOUS remains underutilized in many centers due to factors such as lack of equipment or training (15). There is a growing consensus that standardization of IOUS techniques and increased surgeon familiarity could bridge this gap and enhance surgical outcomes globally.

In summary, the present study reinforces the evidence that intraoperative ultrasound provides significant intraoperative and postoperative benefits in liver tumor surgery. It allows for real-time surgical navigation, improves the detection of lesions not visualized preoperatively, increases resection accuracy, and may reduce early recurrence.

Intraoperative ultrasound significantly enhances the precision of liver tumor resections by improving lesion detection, guiding resection margins, and enabling real-time surgical decision-making. Its use is associated with higher rates of complete tumor removal and better short-term outcomes. Incorporating IOUS into routine hepatic surgery may lead to improved oncologic results and patient safety.

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