Clinical application of personalized biodegradable anastomotic stent via preoperative intestinal three-dimensions reconstruction in laparoscopic resection of rectal cancer

Abstract

BACKGROUND

Anastomotic complications affect postoperative recovery in patients with rectal cancer; therefore, more effective treatment strategies are urgently needed.

AIM

To analyze the clinical value of personalized biodegradable anastomotic reinforcement stents based on preoperative three-dimensional (3D) reconstruction parameters of the intestinal tract in laparoscopic anterior resection for rectal cancer.

METHODS

A total of 82 patients with rectal cancer who were admitted to our hospital between March 2023 and May 2025 were enrolled and divided into control and study groups according to the order of surgery. Both groups underwent laparoscopic anterior resection of the rectal cancer. The control group underwent conventional anastomosis, whereas the study group underwent implantation of personalized biodegradable anastomotic reinforcement stents based on the preoperative 3D reconstruction parameters of the intestinal tract. Perioperative indicators, postoperative recovery, anastomosis-related complications, postoperative inflammatory response levels and follow-up outcomes were compared between the two groups.

RESULTS

The stoma duration was longer in the study group than in the control group (P < 0.05). There were no significant differences in intraoperative blood loss, number of dissected lymph nodes, or conversion rate to open surgery between the two groups (P > 0.05). The time to first bowel sound recovery, time to first flatus, time to first oral intake, and time to first ambulation were shorter in the study group than in the control group (P < 0.05). The total incidence of anastomosis-related complications in the study group was 4.88% (2/41), which was lower than 21.95% (9/41) in the control group, with a significant difference (P < 0.05). The levels of inflammatory indicators at 1 day and 3 days after surgery in the study group were lower than those in the control group (P < 0.05). The Wexner incontinence and low anterior resection syndrome scores at 6 months and 12 months after surgery were significantly lower in the study group than in the control group (P < 0.05).

CONCLUSION

Implantation of personalized biodegradable anastomotic reinforcement stents based on preoperative 3D reconstruction parameters of the intestinal tract can promote postoperative intestinal function recovery, reduce the risk of anastomosis-related complications and inflammatory stimulation, and simultaneously improve postoperative defecation and anal function in patients undergoing laparoscopic anterior resection of rectal cancer.

Key Words: Three-dimensional reconstruction; Personalized; Biodegradable anastomotic reinforcement stent; Rectal cancer; Intestinal function; Complications

Core Tip: Personalized biodegradable anastomotic reinforcement stents designed according to preoperative three-dimensional intestinal reconstruction parameters provide individualized mechanical support after laparoscopic anterior resection for rectal cancer. This study demonstrated that the stents accelerated postoperative bowel function recovery, reduced anastomosis-related complications and postoperative inflammatory responses, and improved long-term anorectal function. These findings suggest that patient-specific biodegradable reinforcement may represent a promising strategy for enhancing anastomotic healing and improving surgical outcomes in rectal cancer.

INTRODUCTION

Laparoscopic anterior resection is currently the standard surgical procedure for the treatment of rectal cancer. It has shown significant advantages in improving radical resection of tumors, reducing traumatic stress, and promoting postoperative recovery[1]. However, postoperative anastomosis-related complications such as anastomotic leakage, bleeding, infection, and stenosis remain key issues limiting the safety of laparoscopic rectal cancer surgery and patient prognosis. Among them, the incidence of anastomotic leakage is as high as 5%-20%, which adversely affects postoperative recovery, may trigger severe systemic inflammatory responses, and even endanger patients’ lives[2,3]. In addition, even in the absence of severe complications, delayed recovery of intestinal function and anal dysfunction after surgery seriously impair patients’ long-term quality of life[4,5].

In recent years, with the popularization of the concept of enhanced recovery after surgery and continuous innovation in surgical techniques, the clinical requirements for the quality of postoperative recovery in patients with rectal cancer have increased. Therefore, ensuring radical tumor resection, effectively reducing the risk of anastomotic complications, promoting early postoperative recovery, and improving long-term functional prognosis have become research hotspots in the field of colorectal surgery[6,7]. As novel surgical auxiliary devices, personalized biodegradable anastomotic stents are expected to improve the anastomotic healing environment and reduce the incidence of complications by providing precise physical support and protection against anastomosis. However, a review of the current relevant literature shows that there is still a lack of research on its combined application with three-dimensional (3D) reconstruction technology, and its clinical application value remains to be verified.

Accordingly, this study selected a subset of patients undergoing laparoscopic anterior resection for rectal cancer in our hospital as research subjects and analyzed the application of personalized biodegradable anastomotic stents in laparoscopic anterior resection for rectal cancer through a controlled study, aiming to accumulate experience in optimizing surgical strategies for rectal cancer and improving patient prognosis.

MATERIALS AND METHODS

General data

A total of 82 patients with rectal cancer admitted to our hospital between March 2023 and May 2025 were enrolled in this study.

The inclusion criteria were as follows: (1) All patients were clinically diagnosed with rectal adenocarcinoma, with clinical stages I-III[8]; (2) The tumor did not invade adjacent organs such as the bladder, uterus, or sacrum; radical resection was feasible; and all met the indications for laparoscopic anterior resection; (3) Basic liver, kidney, and coagulation functions were normal; and (4) No radiotherapy or chemotherapy was performed preoperatively. The exclusion criteria were as follows: (1) Patients with clinical stage IV or locally advanced disease for whom radical resection was not possible; (2) Patients with American Society of Anesthesiologists physical status IV or above; (3) Tumor distance from the anal verge < 5 cm; (4) Patients with distant metastasis or other malignant tumors; and (5) Patients with a history of major abdominal surgery. Although patients with clinical stage III disease were included, not all patients received neoadjuvant therapy. Treatment decisions were individualized based on multidisciplinary team evaluations, patient preferences, comorbidities, tumor characteristics, and contemporary institutional practices during the study period. Therefore, some patients with stage III disease underwent surgery after comprehensive assessment.

The 82 patients were divided into the control and study groups according to the order of surgery. There were no significant differences in baseline data between the two groups (P > 0.05; Table 1).

Table 1 Baseline data of the two groups, n (%)/mean ± SD.

Item	Study group (n = 41)	Control group (n = 41)	χ2/t/Z	P value
Gender			0.051	0.822
Male	24 (58.54)	25 (60.98)
Female	17 (41.46)	16 (39.02)
Age (years)	60.31 ± 5.74	61.52 ± 6.15	0.921	0.360
BMI (kg/m2)	23.86 ± 2.17	24.05 ± 2.31	0.384	0.702
ASA classification			0.058	0.810
Grade II	29 (70.73)	28 (68.29)
Grade III	12 (29.27)	13 (31.71)
Clinical stage			0.005	0.996

BMI: Body mass index; ASA: American Society of Anesthesiologists.

Methods

All patients underwent standard laparoscopic anterior resection. Routine bowel preparation and systemic evaluation were performed preoperatively. General anesthesia was administered with tracheal intubation, and the patients were placed in the modified Trendelenburg lithotomy position. Peripheral venous access and central venous monitoring were also performed.

Pneumoperitoneum was created using the Veress needle technique, with the intra-abdominal pressure maintained at 12-15 mmHg. Trocars were routinely inserted: A 10 mm trocar at the umbilicus as the main operating port, 5 mm and 10 mm trocars in the left and right lower abdomen as auxiliary ports, and a 5 mm port above the pubic symphysis as the observation port. Intraoperative laparoscopic exploration was performed to assess the tumor location, size, invasion scope, and presence of hepatic or intra-abdominal metastases. Radical dissection was initiated after confirming the absence of any contraindications.

Total mesorectal excision principles were strictly followed. The posterior peritoneum was incised at the root of the sigmoid mesocolon, and sharp dissection was performed along the avascular plane between the perirenal fascia and the rectal mesentery. The left ureter and gonadal vessels were sequentially identified, and the hypogastric and pelvic autonomic nerve plexuses were preserved. The inferior mesenteric vessels were then managed and the root of the inferior mesenteric artery was divided using a harmonic scalpel, with the lymph nodes and surrounding fatty tissue at the dissected vascular root. The inferior mesenteric vein was similarly divided 1-2 cm inferior to the inferior mesenteric artery, ensuring adequate vascular control and stump hemostasis.

The distal rectal mesentery was further mobilized to the level of the pelvic fascia. The rectum was transected perpendicular to the longitudinal axis of the bowel using an endoscopic linear cutter ≥ 2 cm distal to the tumor. The proximal bowel was divided at an appropriate level in the sigmoid colon. The specimen was placed in a sterile specimen bag, and the 10 mm left lower abdominal trocar site was extended to 2-3 cm for specimen extraction, which was sent for routine pathological examination.

Control group: The patients in the control group underwent conventional anastomosis with a circular stapler. After bowel transection and specimen extraction, the anvil of the stapler was inserted transanally with its central shaft protruding from the distal rectal stump and connected to the stapler body at the proximal bowel stump. After confirming proper centering of the shaft and exclusion of the mesenteric tissue, the stapler was slowly closed with the pressure maintained at 12-15 kPa and fired to complete the anastomosis.

The stapler was removed immediately and the integrity of the tissue donuts was verified to ensure smooth margins without tissue defects. Laparoscopic inspection was performed for active bleeding and serosal tears at the anastomotic site. The pelvic cavity was irrigated with sterile normal saline to check for air leakage suggestive of occult anastomotic leakage. Traditional hand-suture reinforcement with 3-0 absorbable sutures was performed when necessary.

A 16 Frenc silicone drainage tube was placed behind the pelvic anastomosis, externalized, and fixed through the left lower abdominal auxiliary port. After abdominal irrigation with normal saline and confirmation of hemostasis with no retained instruments, the pneumoperitoneum was released, and the trocar sites were closed layer-by-layer.

Study group: Patients in the study group underwent contrast-enhanced abdominal 64-slice spiral computed tomography one week preoperatively. Scanning data were imported into the Mimics 21.0 medical 3D reconstruction software. Intestinal image segmentation was first performed using thresholding combined with manual correction to eliminate blood vessels, fat, and surrounding organs, and 3D visualization models of the rectum, sigmoid colon, and tumor were reconstructed.

Key anatomical parameters were accurately measured using the software’s measurement module, including proximal bowel diameter, distal bowel diameter, bowel wall thickness at the planned anastomotic site, angulation of the intestinal tract, and tissue gap width around the anastomosis. These parameters were then transferred to an Electro Optical Systems P33 3D printing workstation. A personalized circular reinforcement stent was printed using poly(lactide-co-glycolide) biodegradable material via fused deposition modeling. The inner diameter of the stent was 1-2 mm smaller than the anastomotic diameter to ensure close fitting; its width was 15-20 mm and was adjusted according to bowel wall thickness. Both inner and outer edges of the stent were polished to a blunt finish to avoid injury to the bowel wall and surrounding tissues. The selected material was chosen because of its favorable biocompatibility, established clinical use in absorbable implants, and predictable hydrolytic degradation profile. The stent was designed to provide temporary mechanical support during the critical early phase of anastomotic healing followed by gradual degradation. Because of the retrospective clinical nature of this study, detailed material characterization parameters, including molecular weight distribution, porosity, mechanical strength retention, and in vitro degradation kinetics, were not systematically evaluated and were therefore not included in the present analysis.

After completion of laparoscopic anterior resection and end-to-end anastomosis, a sterile pusher was inserted transanally to deliver the personalized stent to the anastomotic site. Laparoscopic adjustment was performed to ensure complete overlap between the stent center and the anastomosis, with the upper and lower edges covering 5-10 mm of the proximal and distal bowel walls, respectively, to avoid compression of the mesenteric vessels.

The stent was fixed with 3-0 absorbable sutures in four quadrants (anterior, posterior, left, and right) via seromuscular sutures passing through the prefabricated fixation holes on the stent. The sutures penetrated the muscular layer without penetrating the mucosa. Knots were tied to achieve secure, non-loose apposition between the stent and bowel wall, avoiding excessive tension that might compromise the intestinal blood supply.

After stent fixation, laparoscopic assessment of anastomotic perfusion was performed by observing bowel wall color and testing for anastomotic leakage. Pelvic drainage, abdominal irrigation, and wound closure were performed in a manner identical to that in the control group. The stent was left in situ and degraded spontaneously within 3-6 months postoperatively without removal.

Observation indicators

Perioperative indicators: Stoma duration, intraoperative blood loss, and number of harvested lymph nodes were recorded in both groups, and the rate of conversion to open surgery was calculated. In the study group, the planned anastomotic diameter was determined preoperatively using 3D computed tomography reconstruction. Measurements were obtained at the intended proximal and distal bowel transection levels under standardized imaging conditions. Because the intestinal diameter may vary owing to peristalsis and pneumoperitoneum pressure, measurements were performed on multiple reconstructed sections and averaged to reduce variability.

Postoperative recovery: The time to first bowel sound recovery, first flatus, first oral intake, and first ambulation were documented in both groups.

Anastomosis-related complications: Perioperative anastomosis-related complications including anastomotic leakage, bleeding, infection, and stenosis were recorded in both groups.

Inflammatory response levels: Inflammatory indicators were measured at 1day and 3 days postoperatively in both groups. Fasting peripheral venous blood samples (5 mL) were collected in the morning. After centrifugation, the white blood cell (WBC) count was determined using the electrical impedance method, C-reactive protein (CRP) by immunoturbidimetry, procalcitonin (PCT) by electrochemiluminescence immunoassay, and interleukin (IL)-6 by enzyme-linked immunosorbent assay.

Follow-up outcomes: All patients were followed up for 12 months. The Wexner incontinence score[9] and low anterior resection syndrome (LARS) score[10] were evaluated at 6 and 12 months postoperatively in both groups.

The Wexner incontinence score assessed five dimensions: Incontinence for solid stool, liquid stool, gas, need for padding, and impact on lifestyle. The total score ranges from 0 to 20, with higher scores indicating more severe incontinence. The LARS score evaluates defecation frequency, urgency, incontinence for stool (solid, liquid, gas), sensation of incomplete evacuation, difficult defecation, and the need for assisted defecation, with a total score ranging from 0 to 42; higher scores reflect more severe defecatory dysfunction and poorer quality of life.

Statistical analysis

The SPSS software (version 23.0) was used for the data analysis. Enumeration data were expressed as n (%) and analyzed by the χ² test. Measurement data were expressed as mean ± SD and compared between groups using the t-test. Rank data were analyzed using the Z-test. Statistical significance was set at P < 0.05.

RESULTS

Perioperative indicators

The stoma duration in the study group was significantly longer than that in the control group (P < 0.05). There were no statistically significant differences between the two groups in terms of intraoperative blood loss, number of harvested lymph nodes, or conversion rate to open surgery (P > 0.05; Table 2).

Table 2 Perioperative indicators in the two groups, n (%)/mean ± SD.

Item	Study group (n = 41)	Control group (n = 41)	t/adjusted χ2	P value
Stoma duration (minute)	147.31 ± 12.64	139.27 ± 11.83	4.453	0.000
Intraoperative blood loss (mL)	72.56 ± 5.47	73.08 ± 5.32	0.436	0.664
Number of harvested lymph nodes	15.19 ± 2.05	14.87 ± 2.13	0.693	0.490
Conversion to open surgery	2 (4.88)	3 (7.32)	0.000	1.000

Postoperative recovery in both groups

The time to bowel sound recovery, time to first flatus, time to first oral intake, and time to first ambulation were significantly shorter in the study group than in the control group (P < 0.05), as shown in Table 3.

Table 3 Postoperative recovery status in the two groups, mean ± SD (hours).

Item	Study group (n = 41)	Control group (n = 41)	t	P value
Time to first bowel sound recovery	24.18 ± 3.32	29.31 ± 3.47	6.840	< 0.001
Time to first flatus	32.74 ± 3.59	38.45 ± 4.02	6.784	< 0.001
Time to first oral intake	48.63 ± 3.92	52.37 ± 4.15	4.195	< 0.001
Time to first ambulation	29.13 ± 2.56	34.28 ± 2.41	9.379	< 0.001

Anastomosis-related complications

The total incidence of anastomosis-related complications in the study group was 4.88%, which was lower than that in the control group, with a statistically significant difference (P < 0.05), as shown in Table 4.

Table 4 Comparison of anastomotic-related complications between the two groups, n (%).

Group	Anastomotic leakage	Bleeding	Infection	Stricture	Total incidence
Study group (n = 41)	1 (2.44)	0 (0.00)	1 (2.44)	0 (0.00)	2 (4.88)
Control group (n = 41)	4 (9.76)	1 (2.44)	2 (4.88)	2 (4.88)	9 (21.95)
χ2					5.145
P value					0.023

Postoperative inflammatory response in both groups

At 1 day and 3 days postoperatively, the levels of inflammatory indicators, including WBC count, CRP, PCT, and IL-6, in the study group were significantly lower than those in the control group (P < 0.05), as shown in Table 5.

Table 5 Postoperative inflammatory response levels in the two groups, mean ± SD.

Group	WBC (× 109/L)		CRP (mg/L)		PCT (ng/mL)		IL-6 (pg/mL)
	Postoperative 1 day	Postoperative 3 days	Postoperative 1 day	Postoperative 3 days	Postoperative 1 day	Postoperative 3 days	Postoperative 1 day	Postoperative 3 days
Study group (n = 41)	11.27 ± 2.04	7.12 ± 1.56	46.63 ± 5.87	27.14 ± 3.29	0.36 ± 0.08	0.14 ± 0.03	86.91 ± 7.23	31.25 ± 4.13
Control group (n = 41)	12.49 ± 2.13	8.81 ± 4.73	61.25 ± 7.42	32.51 ± 3.85	0.51 ± 0.11	0.28 ± 0.05	101.32 ± 9.45	50.35 ± 6.29
t	2.649	2.173	9.895	6.790	7.062	15.374	7.755	16.253
P value	0.010	0.033	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001

WBC: White blood cell; CRP: C-reactive protein; PCT: Procalcitonin; IL: Interleukin.

Follow-up outcomes of both groups

The follow-up results at 6 months and 12 months postoperatively showed that the Wexner anal incontinence and LARS scores in the study group were significantly lower than those in the control group (P < 0.05), as shown in Table 6.

Table 6 Follow-up outcomes in both groups, mean ± SD (point).

Group	Wexner anal incontinence score		LARS grade
	Postoperative 6 months	Postoperative 12 months	Postoperative 6 months	Postoperative 12 months
Study group (n = 41)	8.41 ± 1.64	6.42 ± 1.35	24.51 ± 4.12	17.55 ± 2.36
Control group (n = 41)	9.36 ± 1.82	7.17 ± 1.22	27.83 ± 4.63	19.28 ± 2.73
t	2.483	2.639	3.430	3.070
P value	0.015	0.010	0.001	0.003

LARS: Low anterior resection syndrome.

DISCUSSION

Laparoscopic anterior resection is a radical surgical procedure used in the treatment of rectal cancer. It has been widely adopted clinically because of its advantages of minimal invasiveness, clear surgical vision, and rapid postoperative recovery[9,10]. It also serves as an important indicator reflecting the minimally invasive level of colorectal surgery[11]. However, anastomosis-related complications and impaired postoperative intestinal functional recovery remain key clinical challenges that urgently need to be addressed[12,13].

With advances in surgical techniques and the development of novel biomaterials, personalized biodegradable anastomotic reinforcement stents have provided a new strategy to further improve the quality of laparoscopic anterior resection. This device exhibited excellent biocompatibility and controllable biodegradability, providing stable mechanical support during the critical period of anastomotic healing. It effectively disperses the intraluminal pressure and anastomotic tension, reduces the risks of tissue traction and ischemia, and forms a local physical barrier that lowers the probability of leakage and contamination of the intestinal contents, thereby creating a more stable and cleaner microenvironment for anastomotic repair[14].

Compared with conventional reinforcement methods, personalized biodegradable stents do not require secondary surgical removal, significantly reduce patient trauma and medical burden, and confer unique advantages in promoting anastomotic healing and lowering complication rates[15]. Nevertheless, the protective efficacy of stents is highly dependent on proper size matching, accurate positioning, and uniform stress distribution. Relying solely on intraoperative visual estimation cannot achieve genuine individualized adaptation, which limits the full realization of its clinical value to some extent.

The established application of preoperative intestinal 3D reconstruction provides important support for the precise implementation of personalized biodegradable anastomotic reinforcement stents[16]. 3D reconstruction allows intuitive visualization of rectal anatomy, tumor location, intestinal diameter, mesenteric thickness, and adjacent vascular structures. It enables the preoperative quantitative assessment of anastomotic tension, blood supply status, and optimal stent parameters, facilitating accurate preoperative planning. Consequently, the stent dimensions, placement position, and fixation angle can better match the patient’s individual anatomical characteristics, maximizing the effect of anastomotic reinforcement[17].

In this study, personalized biodegradable anastomotic reinforcement stents based on preoperative intestinal 3D reconstruction parameters were implanted in the study group, and a comparative analysis was performed of perioperative indicators, postoperative recovery, anastomosis-related complications, postoperative inflammatory response levels, and follow-up outcomes[18]. The results confirmed that this protocol played a significant role in promoting postoperative recovery, reducing complication risks, and improving patient prognosis.

In terms of perioperative indicators, stoma duration was longer in the study group than in the control group (P < 0.05). Moderate prolongation of operative time is a reasonable cost to ensure procedural accuracy during the initial application of new techniques[19]. After completing standard total mesorectal excision and colorectal anastomosis, the study group underwent additional steps of personalized biodegradable stent implantation, positioning, and fixation. This process requires surgeons to accurately judge the anastomotic location, tension, and blood supply based on preoperative 3D reconstruction planning, select appropriately sized stents, and ensure a close fit to achieve optimal support and protection[20]. Furthermore, no significant differences were observed between the two groups in terms of intraoperative blood loss, number of harvested lymph nodes, or conversion rate to open surgery (P > 0.05), confirming the reliability and safety of the protocol.

Regarding postoperative recovery, the time to bowel sound recovery and first flatus in the study group were shorter and the time to first oral intake and first ambulation were earlier than those in the control group (P < 0.05), further demonstrating the positive effect of personalized biodegradable anastomotic stents in accelerating postoperative recovery. Mechanistically, this was mainly attributed to the synergistic protective effect of personalized biodegradable anastomotic reinforcement stents combined with preoperative 3D reconstruction[21]. By providing stable mechanical support for the anastomosis, the stent reduces anastomotic tension and leakage risk, alleviates clinical concerns regarding early mobilization and feeding, and facilitates enhanced recovery after surgery protocols. Meanwhile, the stent reduces inflammatory edema and adhesion around the anastomosis, and decreased local irritation is conducive to early recovery from intestinal peristalsis[22]. A precise preoperative anatomical evaluation standardizes the procedure, minimizes trauma, and attenuates postoperative inflammation, further shortening the time to bowel sound recovery and passage of flatus. Early recovery of intestinal function promotes early oral feeding and ambulation, forming a virtuous rehabilitation cycle[23].

In terms of anastomosis-related complications, the total incidence in the study group was lower than that in the control group (P < 0.05), verifying the advantage of personalized biodegradable anastomotic stents in reducing postoperative anastomotic complications. Anastomotic leakage is one of the most severe complications of rectal cancer surgery and is associated with impaired blood supply, excessive tension, local infection, and other factors. In this study, the physical support of the stent effectively dispersed the anastomotic tension and prevented anastomotic tearing caused by intestinal peristalsis or elevated abdominal pressure. The stent forms a physical barrier that reduces direct irritation and contamination of the anastomosis by the intestinal contents, creating a more stable local environment for tissue healing. In addition, preoperative 3D reconstruction planning allows surgeons to accurately evaluate anastomotic blood supply and select the optimal anastomotic site, fundamentally reducing the risk of anastomotic leakage. The reduction in bleeding and infection was closely related to precise stent placement, with minimal injury to the surrounding tissues. Anastomotic stenosis is also a common complication, and the reduced risk in the study group was mainly attributed to the continuous stent support, which effectively prevented luminal stenosis caused by excessive postoperative scar hyperplasia. Overall, by improving the local healing environment, reducing tension, and lowering infection risk, personalized biodegradable anastomotic stents significantly decreased the incidence of postoperative anastomosis-related complications, enhanced surgical safety and efficacy, and provided a novel strategy for improving prognosis in rectal cancer surgery[24].

Dynamic monitoring of the postoperative inflammatory responses was also performed. The levels of WBC, CRP, PCT, and IL-6 in both groups were high on postoperative day 1 and decreased by day 3; however, the levels in the study group were lower than those in the control group (P < 0.05). This is because personalized biodegradable anastomotic stents effectively suppress systemic postoperative inflammation by reducing anastomotic complications, alleviating tissue injury, and minimizing foreign body stimulation, thereby providing an important physiological basis for rapid postoperative recovery. In addition, the stent provided physical support and protection for the anastomosis with favorable biocompatibility without additional foreign body irritation, allowing effective control of the inflammatory response[25].

An interesting finding of this study was that postoperative inflammatory markers were lower in the stent group, despite the implantation of a biodegradable foreign material. poly(lactide-co-glycolide) is degraded through hydrolysis to lactic and glycolic acids, both of which are subsequently metabolized through the tricarboxylic acid cycle. Although the accumulation of acidic degradation products can theoretically induce local inflammatory responses, no evidence of excessive systemic inflammation was observed in this cohort. One possible explanation is that the protective effect of reduced anastomotic tension and decreased leakage risk outweighs any mild inflammatory response associated with material degradation. Nevertheless, the direct evaluation of degradation kinetics and local tissue reactions is beyond the scope of this study and warrants further investigation.

In terms of long-term postoperative follow-up, the Wexner anal incontinence and LARS scores in the study group were significantly lower than those in the control group at 6 months and 12 months postoperatively (P < 0.05), indicating a better recovery of anal continence in the study group. This is explained by effective stent protection that markedly reduces severe complications, such as anastomotic leakage and stenosis, avoiding secondary surgery or long-term anal dysfunction caused by complications. Meanwhile, stent support maintained normal anastomotic morphology and tension, reducing the impact of postoperative scar tissue on anal sphincter function and creating a favorable anatomical basis for the recovery of anal continence. Other studies have shown that the development of LARS is closely related to multiple surgical effects on rectal reservoir function, innervation, and intestinal motility. In this study, stent application not only reduced anastomotic complications, but also effectively shortened the duration of intestinal dysfunction by attenuating postoperative inflammation and promoting early recovery of intestinal function. Furthermore, earlier ambulation and oral feeding helped to rebalance the intestinal flora and improve intestinal motility, thereby alleviating LARS-related symptoms. From a translational perspective, a personalized approach increases preoperative planning requirements and material costs. Additional expenditures are associated with enhanced computed tomography imaging, 3D reconstruction software, additive manufacturing equipment, and biodegradable materials. Compared with conventional reinforcement strategies such as fibrin sealants or biosynthetic meshes, the current technique requires greater technical resources and infrastructure. However, if the reduction in anastomotic complications demonstrated in this study is confirmed in larger prospective trials, the associated decrease in reoperations, prolonged hospitalization, and management of anastomotic leakage may offset the initial costs. Formal cost-effectiveness analyses are required before widespread adoption is recommended. This study had several limitations. First, this was a single-center study with a relatively small sample size, which may have limited the generalizability of our findings. Second, the patients were allocated according to the order of surgery rather than by randomization. Although the baseline characteristics were comparable between the groups, selection bias and unmeasured confounding factors could not be excluded. In particular, surgeon experience, learning curve effects, and temporal changes in perioperative management may have influenced outcomes. Third, detailed characterization of the poly(lactide-co-glycolide) stent, including its mechanical properties and degradation kinetics, was not possible. Fourth, a direct in vivo evaluation of stent degradation was not performed. Finally, cost-effectiveness was not formally analyzed. These issues should be addressed in future multicenter, randomized controlled studies.

CONCLUSION

In conclusion, preoperative intestinal 3D reconstruction combined with personalized biodegradable anastomotic reinforcement stents appears to be a feasible and promising adjunct to laparoscopic anterior resection of rectal cancer. This technique was associated with faster postoperative recovery, lower inflammatory responses, fewer anastomosis-related complications, and improved functional outcomes. However, given the non-randomized design and lack of direct degradation assessment, larger prospective multicenter studies are required to validate these findings and determine the long-term clinical and economic benefits.