Introduction:

Ordinary Sponge Group: The size of the traditional VSD (Vacuum Sealing Drainage) sponge was approximately 10 cm × 15 cm × 1 cm. Based on the diameter of the intervertebral foramen and the height of the intervertebral space measured after debridement, the sponge was trimmed to an appropriate size. After gentle retraction and protection of the nerve roots, the sponge was carefully inserted into the intervertebral space using long forceps and subsequently sutured securely to the wound margin. A biological semipermeable membrane was used to quickly cover the surface sponge over the wound and the surrounding skin tissue. A negative-pressure drainage system was immediately established, with the negative pressure maintained at 125 mmHg (1 mmHg = 0.133 kPa) (Figure 1-B).

Evaluation Indicators

The duration of sponge implantation into the intervertebral space during surgery, intraoperative blood loss, and the mean daily drainage volume on postoperative day 3 were compared between the two groups, with statistical analysis performed accordingly.

Statistical Methods

Statistical analysis was performed using SPSS 22.0 software. Measurement data were expressed as mean ± standard deviation (x±s). When the data followed a normal distribution, the independent samples t-test was used for comparison between the two groups; when the data showed a non-normal distribution, the rank-sum test was applied. Enumeration data were tested using the chi-square test (χ² test) or Fisher's exact probability test. A P-value less than 0.05 (P<0.05) was considered statistically significant.

Results

Both groups of patients successfully underwent the surgical procedures without complications. A comparative analysis of perioperative outcomes revealed that the mean implantation time in the compressed sponge group was 6.55 ± 1.51 minutes, significantly shorter than the 20.6 ± 2.55 minutes observed in the conventional sponge group. Intraoperative blood loss was also markedly lower in the compressed sponge group (77.27 ± 4.34 mL) compared to the conventional sponge group (113.2 ± 3.67 mL). With regard to postoperative drainage, the compressed sponge group exhibited a higher mean drainage volume (65.09±3.02 mL) than the conventional sponge group (54.3±2.83 mL), indicating more effective fluid clearance. Statistical analysis demonstrated that the differences in implantation time, intraoperative blood loss, and postoperative drainage volume between the two groups were all statistically significant (P < 0.001). Detailed results are presented in Table 1. These findings suggest that the use of compressed sponges is associated with reduced operative duration, decreased intraoperative bleeding, and improved postoperative drainage compared to conventional sponges.

Discussion

In the surgical management of spinal infections, multiple operative approaches are available. The conventional posterior decompression combined with debridement typically involves a single posterior approach to resect the ipsilateral lamina, facet joint, or costotransverse joint, along with a segment of adjacent rib, and occasionally the spinous process when necessary [3]. This strategy aims to preserve the integrity of the ipsilateral pedicle and contralateral facet joints as well as partial lamina, thereby minimizing disruption to spinal stability [9–11]. The expanded intervertebral foramen approach necessitates removal of only a portion of the lamina and facet joint, while preserving the ipsilateral pedicle along with the majority of the lamina and facet joints. This technique involves less dissection of surrounding soft tissues, offering the advantages of reduced trauma, minimized bleeding, and better preservation of lumbar facet joint stability [4, 12, 13]. The expanded intervertebral foramen approach achieves comparable decompression to conventional TILF surgery, enables thorough debridement of infected lesions, and simultaneously minimizes iatrogenic tissue damage while mitigating the risk of infection dissemination.

Vacuum sealing drainage (VSD) technology has matured significantly in managing spinal infections. Clinical studies confirm that VSD-generated negative pressure effectively reduces local bacterial load, resolves interstitial edema, enhances blood perfusion, and promotes cellular proliferation with granulation tissue formation. This approach improves perioperative infection control safety and efficacy while minimizing iatrogenic impact on neural structures, dura mater, and vasculature. For primary spinal infections, negative pressure suction devices demonstrate superior short-term clinical outcomes compared to conventional surgery [14-17].Regarding negative pressure sponge implantation, traditional methods position the sponge superficially to the deep fascial layer. Although distanced from nerve roots for enhanced safety, this technique fails to deliver negative pressure directly to intervertebral lesions, resulting in inadequate drainage and prolonged treatment cycles [18, 19]. Xing Hao et al. demonstrated that transforaminal implantation of the sponge into the intervertebral space enables immediate aspiration of exudates, necrotic debris, and pathogens. This disrupts bacterial microenvironments, accelerates granulation tissue development, and significantly shortens spinal infection treatment duration [20].

Comparative analysis of compressed versus conventional sponges in expanded intervertebral foramen approach surgeries demonstrated significant advantages of compressed sponges in reducing operative duration, minimizing intraoperative blood loss, and achieving optimal postoperative drainage efficacy. No statistically significant intergroup differences were observed in perioperative complication rates. These findings indicate that compressed sponges offer enhanced clinical utility and greater practical adoption potential in spinal surgical workflows.

Comparative analysis of compressed versus conventional sponges demonstrated significant advantages of compressed sponges in reducing operative duration, minimizing intraoperative blood loss, achieving effective postoperative drainage, and decreasing surgical trauma. As a retrospective case-control study with limited sample size, these findings necessitate further validation through large-scale, multicenter randomized controlled trials with medium-to-long-term follow-up.

Conflict of Interest

The authors declare no competing financial or non-financial interests relevant to this work.

Author Contributions

Shiwei Ren：Conceptualized the study design; conducted data collection and curation; prepared the original draft. Zhengqi Chang: Acquired funding resources; performed surgical interventions and clinical validation; supervised manuscript preparation and critical revision. 

Funding

This research was supported by Natural Science Foundation of Shandong Province (Award Number: ZR2023MH331; Grant Recipient: Zhengqi Chang).