Efficacy of silver-ion dressings in accelerating wound healing after hemorrhoidectomy: a dual-center randomized trial

Abstract

Background

Hemorrhoids are a prevalent perianal disorder, with surgery being a primary treatment modality. Postoperative wound healing significantly impacts recovery and quality of life. Silver-ion dressings, known for their antimicrobial properties, are a relatively new option, but their efficacy in perianal wound healing is not well-established.

Objective

To determine if silver-ion dressings, compared to petrolatum gauze, accelerate wound healing and improve outcomes following hemorrhoidectomy.

Design, setting, and participants

A dual-center, prospective, randomized clinical trial was conducted from March 2021 to April 2022 at The Fifth Affiliated Hospital of Sun Yat-sen University and Shenzhen Second People’s Hospital. 112 patients undergoing open hemorrhoidectomy were enrolled based on predefined inclusion/exclusion criteria.

Interventions

Patients were randomized 1:1 to either petrolatum gauze covered with woven sterile gauze (Control, n = 50) or silver-ion dressings (Experimental, n = 52). Dressings were changed every 24 h.

Main outcomes and measures

The primary outcome was time to complete epithelialization. Secondary outcomes included the incidence of wound infection, bacterial culture positivity from wound secretions, pain, wound edema (scored on a 3-point scale: 0 = none, 3 = severe), and dressing usability (using a 4-point scale).

Methods

112 patients were enrolled. Participants were randomized to conventional wound care or silver-ion dressing treatment. Postoperative wound healing progression was tracked in both groups, and differences in healing time, pain scores, edema severity, dressing performance, and infection rates were compared. Preoperative and postoperative (day 21 ± 1) blood and urine samples were collected for complete blood count, urinalysis, and liver/kidney function tests to assess safety.

Results

102 patients completed the study. The median time to complete epithelialization in the silver ion dressing group (22 days, IQR 21–24.75) was significantly shorter than the control group (29 days, IQR 26.75–32) (P = 0.008). While pain scores were slightly lower in the silver ion group, the difference was not statistically significant (VAS score difference: 0.5, P = 0.766). Anal edema scores were similar between groups (P = 0.619). No postoperative infections occurred. Bacterial culture positivity rates were not significantly different between groups at baseline (P = 0.820) or on postoperative day 14 (P = 0.908). No adverse events were reported in either group.

Conclusion

Silver-ion dressings reduce post-hemorrhoidectomy wound healing time versus conventional petrolatum-based dressings, promoting earlier return to work and improved the overall wound dressing experience.

Trial registration

This study was approved and registered by the Chinese Clinical Trial Center, Registration number: ChiCTR2000039169, Registration time: October 20, 2020 (https://www.chictr.org.cn/).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-025-04525-3.

Background

Hemorrhoids are a highly prevalent condition, affecting a significant portion of the adult population and leading to substantial healthcare resource utilization [1–5]. While various non-surgical treatments exist, including pharmacotherapy and lifestyle modifications, surgical excision remains a crucial intervention for patients with severe or refractory symptoms [6–8]. Common surgical techniques for hemorrhoidectomy include the open wound method (Milligan-Morgan procedure), the closed wound method (Ferguson procedure), the semi-open wound method (Parks procedure), hemorrhoidal ligation with sclerotherapy, and circumferential hemorrhoidectomy [7, 9, 10]. However, regardless of the technique employed, the unique anatomical location of the surgical incision in the perianal region presents a significant challenge: a high risk of fecal contamination. This, coupled with daily bowel movements, can lead to exacerbated patient pain, delayed wound healing, and an increased incidence of postoperative complications such as wound pain, infection, and anal edema, all of which significantly impair patients’ quality of life [11]. Therefore, postoperative wound care following hemorrhoidectomy is of paramount importance. Conventional postoperative wound care, typically involving maintaining a dry wound surface, applying petrolatum gauze strips, and covering the area with sterile gauze secured by adhesive tape [6], often proves inadequate in preventing wound contamination due to frequent dressing detachment. This can lead to higher infection rates and prolonged healing times, underscoring the need for improved wound management strategies.

Silver-containing dressings have emerged as a promising alternative, exhibiting excellent broad-spectrum antibacterial properties with a reduced risk of inducing bacterial resistance [12, 13]. Silver nanoparticles demonstrate broad-spectrum antibacterial, antifungal, and antiviral properties. These nanoparticles can penetrate bacterial cell walls, alter cell membrane structures, and even induce cell death. Additionally, they enhance membrane permeability, generate reactive oxygen species (ROS), and disrupt DNA replication through the release of silver ions [14]. Furthermore, silver ions have demonstrated potential anti-inflammatory effects and the ability to promote tissue regeneration, offering a multifaceted approach to wound healing. Silver ion-based materials have been successfully applied in various fields of dentistry and oral healthcare [15], demonstrating their biocompatibility and efficacy in controlling microbial infections.

This study utilizes a newly developed silver ion-based anorectal functional dressing, specifically designed to address the challenges of postoperative wound care following hemorrhoidectomy. Despite the promising in-vitro and in-vivo evidence supporting the use of silver-containing dressings, there is a relative paucity of robust clinical data specifically evaluating their efficacy in the context of hemorrhoidectomy wounds. Therefore, this prospective, dual-center, randomized trial was conducted across two medical centers to investigate the efficacy of silver-ion dressings compared to traditional wound care in promoting postoperative wound healing, reducing pain, and minimizing complications following hemorrhoidectomy.

Methods

This study received ethical approval from the Ethics Committees of the Fifth Affiliated Hospital of Sun Yat-sen University and the Second People’s Hospital of Shenzhen. The trial was conducted and reported in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines. All participants provided written informed consent prior to enrollment.

Study design and participants

This prospective, dual-center, randomized controlled trial was conducted at the Second People’s Hospital of Shenzhen and the Fifth Affiliated Hospital of Sun Yat-sen University. Patients undergoing hemorrhoidectomy at these two medical centers were screened for eligibility and recruited. Written informed consent was obtained from all participants prior to any study-related procedures. At enrollment, demographic data were collected, including gender, age, height, weight, relevant medical history (e.g., diabetes mellitus, metabolic syndrome), and allergy history. All patients included in the study had undergone a hemorrhoidectomy resulting in an open wound. The definition of metabolic syndrome was based on the criteria established by Howard et al. [16]. Furthermore, to eliminate the potential confounding effects of hyperglycemia on wound healing, patients with poorly controlled blood glucose were excluded from this study.

Patients meeting any of the following exclusion criteria were excluded from participation: (I) Known allergy to silver; (II) Severe comorbidities affecting the cardiovascular, hepatic, renal, or hematologic systems; (III) Presence of severe postoperative complications or systemic infections; (IV) Acute metabolic disorder; (V) Severe immune system disorder; (VI) Poorly controlled blood glucose (glucose level > 10 mmol/L for more than 2 weeks despite medical management); (VII) Pregnancy or lactation; (VIII) Inability to adhere to the study protocol or complete the course of treatment.

Any patient who withdrew from the study for any reason was documented in the study records, including the reason(s) for withdrawal. A total of 112 patients were initially enrolled in the trial. Of these, 102 patients completed the study protocol, with 52 participants from the Fifth Affiliated Hospital of Sun Yat-sen University and 50 participants from the Second People’s Hospital of Shenzhen. The participant enrollment flow is illustrated in Fig. 1.

Fig. 1.

Flowchart of the enrollment process

Randomization and blinding procedures

Stratified by center, a randomization schedule was generated using SPSS 26.0 statistical software with a predetermined seed number and block length. A total of 120 subject slots (60 per center) were allocated, with subject case numbers ranging from 001 to 060 for the first center and 061 to 120 for the second center. The randomization code table assigned subjects to either the experimental or control group in a 1:1 ratio within each center. Upon enrollment, each subject received a unique case number based on their enrollment sequence, and the corresponding treatment group was determined by referencing the randomization code table.

Due to the distinct nature of the postoperative wound care methods, blinding of investigators and participants to treatment allocation was not feasible. Therefore, this trial was conducted as an open-label study. However, to mitigate subjective bias in outcome assessment, Investigator 2, an independent assessor blinded to the treatment allocation, evaluated the primary endpoint – wound healing time. Investigator 1, responsible for administering wound care during follow-up visits, did not participate in the assessment of wound healing outcomes.

This trial was designed as a superiority study. Superiority would be established if the lower limit of the 95% confidence interval (CI) for the difference in wound healing time between the control and experimental groups exceeded the predefined superiority margin, indicating a statistically significant benefit of the experimental treatment.

Procedures

All patients underwent open hemorrhoidectomy under spinal anesthesia. Postoperatively, standard wound management was performed, with different wound care methods applied based on group assignment. In the experimental group, patients received silver ion-based anorectal functional dressings, changed according to the amount of wound exudate and the wound condition. In the control group, patients received petrolatum gauze strips to protect the wound edges, covered with sterile gauze, and secured with adhesive tape. The silver-ion dressing used in this study is a proprietary product developed by a company from Shenzhen China. The dressing consists of a functional layer, an absorbent layer, an adhesive layer, and a release liner. The functional layer is composed of silver ions integrated into a medical cotton fabric substrate, which may be covered with a mesh anti-adhesion film. The silver-ion dressing used has overall dimensions of 14.5 cm × 24 cm, with an absorbent core measuring 6 cm × 15 cm. The silver content in the functional layer ranges from 1.2 to 3.0 mg/g. Designed to be affixed inside underwear, the product is suitable for post-hemorrhoidectomy wound care.

Following wound care initiation, patients in both groups were followed up through outpatient wound assessments. The first follow-up occurred at 3 ± 1 days post-treatment or at discharge, and the second follow-up occurred at 14 ± 1 days post-treatment. Subsequent follow-up visits were scheduled every 3 ± 1 days until complete wound healing was achieved. Investigators could adjust follow-up intervals based on individual wound conditions. The independent, blinded investigator (Investigator 2) assessed wounds and recorded the wound healing time. Wound pain scores, wound edema severity, and dressing performance were also documented during the first and second follow-up visits.

Preoperative complete blood count (CBC), urinalysis, and liver/kidney function tests were recorded as baseline safety data. These tests were repeated on postoperative day 21 ± 1 or at the time of wound healing to assess the safety profile of the interventions.

Outcomes

The primary outcome measure was wound healing time, defined as the time from the surgery date to complete wound healing, as assessed by an independent investigator blinded to treatment allocation and not involved in wound care procedures. Complete wound healing was defined as the presence of granulation tissue covered by epithelium, a smooth digital rectal examination without anal stenosis or incontinence, and the absence of pain or bleeding upon examination.

Secondary outcome measures included: Incidence of wound infection. Bacterial culture results from wound secretions, including identification and distribution of microbial species. Wound pain scores, assessed using the Visual Analog Scale [17]. Severity of wound edema, graded based on pre-defined clinical criteria (Table 5). Dressing performance scores, assessing factors such as adherence, ease of application, and patient comfort, based on patient feedback (Table 6).

Table 5.

Scoring criteria for dressing performance evaluation

Usage status	Scores
The product may detach within 8 h of normal use, and it is inconvenient for the subjects to replace the product themselves	1
There is no shedding of the product within 8 h of normal use, and it is inconvenient for the subjects to replace the product themselves	2
The product may detach within 8 h of normal use, and it is convenient for the subjects to replace the product themselves	3
There is no shedding of the product within 8 h of normal use, and it is convenient for the subjects to replace the product themselves	4

Table 6.

Pre- and Post-Intervention comparison of CBC parameters between experimental and control groups

Complete Blood Count (CBC)
		On the 21 st ± 1 st day after surgery				χ²	P value
	preoperative	normal	Abnormal without clinical significance	Abnormal with clinical significance	total	1.605	0.808
Silver group	normal	33	6	0	39
	Abnormal without clinical significance	3	9	0	12
	Abnormal with clinical significance	0	0	1	1
	total	36	15	1	52
Control group	normal	34	8	0	42
	Abnormal without clinical significance	2	5	0	7
	Abnormal with clinical significance	0	0	1	1
	total	36	13	1	50

These measures were systematically documented during follow-up visits to comprehensively evaluate the efficacy and safety of the wound care interventions. Wound infection was defined by the presence of one or more of the following clinical signs and symptoms: typical signs of infection (erythema, edema, heat, pain, or cellulitis); additional indicators (purulent discharge, thick or viscous exudate, discoloration of the wound edges or surrounding tissue, friable granulation tissue prone to bleeding, abnormal wound pain, or foul odor). In cases where the investigator suspected a wound infection, a bacteriological culture of wound secretions was performed to confirm the diagnosis.

Wound secretion samples were collected for bacterial culture at two time points: prior to the initiation of treatment (experimental or control) following surgery and on postoperative day 14 ± 1.

The severity of anal edema was evaluated by the investigator during each follow-up visit based on pre-defined scoring criteria (Table 5), established by an independent researcher. Regarding dressing performance, the investigator documented patient feedback on product use (experimental or control) between follow-up visits, using the scoring criteria outlined in Table 6.

Statistical analysis

Data analysis was performed using SPSS 26.0 software. Continuous variables were compared using the Mann-Whitney U test, and categorical variables were analyzed using the chi-square test. Survival analysis was conducted using the Kaplan-Meier method, and univariate comparisons were performed with the log-rank test. A two-tailed significance level of P < 0.05 was used for all statistical tests.

Results

Handling of loss to Follow-up

Of the 112 participants originally enrolled, 10 were lost to follow-up after hemorrhoidectomy due to relocation beyond the study center’s catchment area. These losses comprised four participants in the silver group (7.0% loss-to-follow-up) and six in the control group (10.7%), resulting in an overall rate of 8.9%. In accordance with contemporary RCT guidelines [18], the missing data were classified as Missing Completely at Random (MCAR). No participants dropped out due to intervention-related adverse events, such as silver-ion dressing allergy or wound discomfort. Given the low dropout rate (< 10%; 8.9% in this trial) and MCAR status, the risk of bias is minimal. This justifies the use of a complete-case analysis to handle the limited attrition. Therefore, the primary analysis included only the 102 participants who completed the study. The baseline characteristics of the entire enrolled cohort (n = 112) are presented in Supplement Table 1.

Comparison of baseline characteristics between the experimental and control groups

Baseline characteristics of the experimental group (silver-ion dressings) and the control group (petrolatum gauze and sterile gauze) were compared to ensure adequate balance between the two groups. This clinical trial enrolled a total of 112 participants across two centers, randomized to either the experimental or control group. Of these, 102 participants completed the trial, resulting in a dropout rate of 8.9%. Specifically, 56 participants were enrolled at the Second People’s Hospital of Shenzhen (April 2021 to April 2022), with 6 dropouts, and 56 participants were enrolled at the Fifth Affiliated Hospital of Sun Yat-sen University (March 2021 to March 2022), with 4 dropouts.

The median age of participants was 38 years in the experimental group and 34 years in the control group (t = 1.617, P > 0.05). A summary of baseline characteristics for both groups is presented in Table 1, demonstrating no significant differences and supporting the validity of the randomized study design.

Table 1.

Enrollment and baseline characteristics

	Silver group	Control group	95%CI	P
Gender				0.703
male	29(55.8)	26(52)
female	23(44.2)	24(48)
Age (years)	38(32.25—49)	34(29.75—45.25)	−6.699—1.54	0.999
Height (m)	1.65(1.58—1.72)	1.66(1.58—1.71)	−0.033—0.029	0.909
Weight (kg)	62(55—71.38)	60(55—70)	−5.688—2.971	0.779
Metabolic Syndrome				0.846
Positive	25(48.1)	25(50)
Negative	27(51.9)	25(50)

(Categorical data is presented as percentages, while continuous data is presented as median (IQR).)

Effectiveness evaluation analysis

The primary outcome measure of this study was wound healing time, defined as the duration from the date of surgery to complete wound healing. Postoperative wound healing after hemorrhoidectomy was determined by the following criteria: granulation tissue covered by epithelium, a smooth digital rectal examination without anal stenosis or incontinence, and the absence of pain or bleeding during protocol-specified follow-up visits.

The median wound healing time in the experimental group was 22 days (IQR: 21–24.75), significantly shorter than the 29 days (IQR: 26.75–32) observed in the control group (P < 0.05, Fig. 2). Further univariate Cox regression analysis (Table 2) identified treatment group allocation as an independent factor influencing wound healing. A log-rank test also yielded a statistically significant difference (P < 0.001), and the survival analysis curve is presented in Fig. 3. These results indicate that silver-ion dressings significantly reduced wound healing time compared to conventional wound care methods. The analysis of secondary outcome measures is summarized in Table 3.

Fig. 2.

Comparison of Healing Time Between the Silver Group and the Control Group

Table 2.

Univariate Cox regression analysis of wound healing time

		Hazard ratio	HR (95%CI for HR)	P value
Gender		1.099	0.743–1.627	0.636
Age (years)		1.006	0.987–1.025	0.562
Height (m)		0.409	0.032–5.204	0.491
Weight (kg)		0.994	0.977–1.012	0.516
Metabolic Syndrome		0.981	0.664–1.450	0.924
Group		4.494	2.785–7.254	<0.001

Fig. 3.

Survival Analysis of Wound Healing Time

Table 3.

Effectiveness evaluation results

	Silver group	Control group	95%CI	P
Wound healing time (days)	22(21—24.75)	29（26.75—32）	4.211—6.792	0.008
Results of the First Follow-Up
Wound Pain Score	3(2—4)	3(3—4)	−0.189—0.713	0.506
Wound Edema Severity Score	1(1—1)	1(1—1.25)	−0.077—0.365	0.812
Dressing Performance Score	4(4—4)	2(2—2)	−2.039—1.564	＜0.001
Results of the Second Follow-Up
Wound Pain Score	0(0—1)	1(1—2)
Wound Edema Severity Score	0(0—0)	0(0—1)
Dressing Performance Score	4(4—4)	2(2—2)
Maximum Wound Pain Score During Follow-Up	3(2—4)	3(3—4)	−0.157—0.723	0.766
Maximum Anal Edema Severity Score During Follow-Up	1(1—1)	1(1—2)	−0.059—0.387	0.619
Maximum Dressing Performance Score During Follow-Up	4(4—4)	2(2—2)	−1.940—1.503	＜0.001
Minimum Dressing Performance Score During Follow-Up	4(4—4)	2(2—2)	−2.180—1.703	＜0.001
Preoperative Infection
Positive	0(0)	0(0)
Negative	52(100%)	52(100%)
Postoperative Infection Prior to Wound Healing
Positive	0(0)	0(0)
Negative	52(100%)	52(100%)
Results of the First Postoperative Bacterial Culture				0.82
Positive	29(55.8%)	29(58%)
Negative	23(44.2%)	21(42%)
Results of Bacterial Culture on Postoperative Day 14 ± 1				0.908
Positive	13(25%)	13(26%)
Negative	39(75%)	37(74%)

(Categorical data is presented as percentages, while continuous data is presented as median (IQR).)

Incidence of wound infection

Investigators monitored and recorded all instances of wound infection during the treatment period and calculated the wound infection rates for both groups. No preoperative or postoperative wound infections occurred in either the experimental or control groups.

Positive rate of bacterial cultures

Wound secretion samples were collected for bacterial culture on postoperative day 1 and on day 14 ± 1 after treatment initiation. The bacterial species identified were recorded. On postoperative day 1, positive bacterial culture results were observed in 29 cases (55.8%) in the experimental group and 29 cases (58%) in the control group. By day 14 ± 1, the positive rate was 25% in the experimental group and 26% in the control group. Escherichia coli was the most commonly identified bacterial species. No statistically significant differences in positive culture rates were observed between the two groups at either time point (P > 0.05).

Wound pain assessment

Wound pain was evaluated using the Visual Analog Scale (VAS). Wound pain scores were recorded at protocol-specified follow-up time points. No significant differences in wound pain scores were observed between the experimental and control groups at either the first or second follow-up visits (P > 0.05). Furthermore, there were no differences between the groups in terms of the maximum pain scores recorded during the follow-up period.

Anal edema assessment

The severity of anal edema was observed and scored based on the evaluation criteria outlined in Table 4. No significant differences in anal edema scores were observed between the experimental and control groups at either the first or second follow-up visits (P > 0.05). Similarly, there were no differences between the groups in terms of the maximum anal edema scores recorded during the follow-up period.

Table 4.

Wound edema severity score

Anal edema condition	Score
No obvious edema	0
Mild edema, slight protrusion of anal margin tissue, and presence of skin lines	1
Moderate edema, moderate protrusion of anal margin tissue, and disappearance of skin lines	2
Severe edema, severe protrusion of anal margin tissue, disappearance of skin lines with shiny skin	3

Dressing performance evaluation

During each follow-up visit, investigators documented participant feedback regarding product use (experimental or control) between visits. A dressing performance score, based on predefined evaluation criteria (Table 5), was assigned and recorded. At both the first and second follow-up visits, participants in the experimental group reported significantly higher satisfaction with dressing performance compared to those in the control group (P < 0.05). These findings indicate that the experimental dressing offered a more satisfactory user experience than the traditional dressing.

Safety evaluation analysis

A safety analysis was conducted to assess potential adverse risks associated with the novel dressing. No adverse events were reported in either the experimental or control groups during the study period. Complete blood count (CBC), urinalysis, and liver/kidney function tests were performed at baseline and on postoperative day 21 ± 1 or at the time of wound healing to monitor changes in physiological indicators (Table 6: Pre- and Post-Intervention Comparison of CBC Parameters Between Experimental and Control Groups-1,2,3). The analysis revealed no significant changes in CBC, urinalysis, or liver/kidney function between the two time points in either group (P > 0.05). These findings indicate that the novel dressing does not increase the risk of harm to patients compared to traditional wound care methods (Tables 7 and 8).

Table 7.

Pre- and Post-Intervention comparison of Urinalysis parameters between experimental and control groups

Urinalysis
		On the 21 st ± 1 st day after surgery				χ²	P value
	preoperative	normal	Abnormal without clinical significance	Abnormal with clinical significance	total	3.132	0.536
Silver group	normal	28	7	0	35
	Abnormal without clinical significance	12	4	0	16
	Abnormal with clinical significance	1	0	0	1
	total	41	11	0	52
Control group	normal	33	5	0	38
	Abnormal without clinical significance	7	5	0	12
	Abnormal with clinical significance	0	0	0	0
	total	40	10	0	50

Table 8.

Pre- and Post-Intervention comparison of liver and kidney function tests parameters between experimental and control groups

Liver and kidney function tests
		On the 21 st ± 1 st day after surgery				χ²	P value
	preoperative	normal	Abnormal without clinical significance	Abnormal with clinical significance	total	1.862	0.761
Silver group	normal	18	8	0	26
	Abnormal without clinical significance	12	13	0	25
	Abnormal with clinical significance	0	0	1	1
	total	30	21	1	52
Control group	normal	20	10	0	30
	Abnormal without clinical significance	10	10	0	20
	Abnormal with clinical significance	0	0	0	0
	total	30	20	0	50

Discussion

Hemorrhoids are the most common benign anorectal disorder [1, 2]. Surgery remains a primary and effective treatment for hemorrhoids, alleviating symptoms. However, postoperative anal wounds can lead to prolonged pain and potential infection, significantly impacting patients’ quality of life [11]. Traditional wound care, involving petrolatum gauze and sterile dressings, is prone to detachment and may increase infection risk if not properly managed during dressing changes. Silver-ion dressings, a novel wound care material, exhibit excellent antimicrobial properties [19].

This dual-center, prospective, randomized controlled trial provides high-quality evidence supporting the use of silver-ion dressings for wound management after hemorrhoidectomy. Of the 112 enrolled patients, 102 completed the study per protocol. Ten participants discontinued the study: six from Shenzhen Second People’s Hospital and four from The Fifth Affiliated Hospital of Sun Yat-sen University. These participants were lost to follow-up because they relocated away from the catchment area of the study center. Following the CONSORT guidelines for intention-to-treat (ITT) analysis, we re-analyzed the primary outcome using a worst-case imputation strategy. Specifically, missing values in the experimental group were imputed with the longest healing time observed in that group (29 days), whereas those in the control group were imputed with the shortest healing time from the experimental group (21 days). Under this conservative approach, the mean healing time was 23.46 days for the experimental group and 27.73 days for the control group (P = 0.04). This result reinforces the primary finding that silver-ion dressings accelerate wound healing following hemorrhoidectomy. The corresponding time-to-event curve for wound healing, based on the ITT analysis, is provided in Supplement Fig. 1.

Among the 102 patients who completed the trial, the median time to complete wound epithelialization was 22 days in the silver dressing group, significantly shorter than the 29 days in the conventional care group (P = 0.008). This 7-day reduction in healing time is clinically substantial, as it facilitates earlier recovery of anal function and improves patient quality of life. However, secondary outcomes, including VAS pain scores (P = 0.766), anal edema (P = 0.619), wound infection rate (0% in both groups), and positive bacterial culture rates (P = 0.820 at baseline; P = 0.908 on day 14 post-operation), did not differ significantly between groups. These findings suggest that the accelerated wound healing associated with silver-ion dressings is not mediated by reduced pain or edema, nor does it rely on the control of clinically overt infection. The absence of postoperative infections may be attributed to strict intraoperative aseptic techniques, standardized postoperative care protocols, and the exclusion of high-risk patients with significant comorbidities, such as poorly controlled diabetes.

The dressing performance score was significantly superior in the silver ion group compared to the control group (P < 0.001). Based on predefined criteria, this superior score indicates that the silver-ion dressings remained securely in place for ≥ 8 h during normal activity and allowed for patient self-replacement. This property effectively addresses the frequent dislodgement common with traditional Vaseline gauze, which often results from perianal movement or fecal contamination. Consequently, silver-ion dressings provide a stable microenvironment that promotes wound healing.

The safety profile further supports the clinical adoption of this dressing. No adverse events were reported during the trial. Furthermore, laboratory tests, including complete blood count, urinalysis, and hepatic and renal function, conducted preoperatively and on postoperative day 21 ± 1 revealed no significant abnormalities (P >0.05). These results confirm the biocompatibility of the silver ion dressing, which is consistent with the established safety profile of silver-based materials in other clinical applications, such as dentistry [15].

This study demonstrated accelerated wound healing in the experimental group, attributed to the synergistic biological properties and physical design of the silver-ion dressing, which is particularly suited for perianal wounds in a contaminated environment. First, perianal wounds are continuously exposed to fecal flora; E. coli was the most frequently identified bacterium in this study. Ag⁺ exerts antimicrobial effects through multiple mechanisms, including disrupting bacterial cell walls and generating reactive oxygen species (ROS) [14], and demonstrates a low propensity for inducing bacterial resistance [13]. Although the positive culture rates did not differ significantly between groups, Ag⁺ may suppress pathogenic proliferation at a subclinical level, thereby mitigating low-grade infection and facilitating healing. Second, although localized inflammation is necessary for healing, excessive inflammation can impede repair [20]. Ag⁺ reduces the release of pro-inflammatory cytokines (e.g., TNF-α and IL-6) and inhibits inflammatory cell infiltration [19]. In the perianal region, which is highly susceptible to mechanical and chemical irritation from feces, Ag⁺ may promote a more orderly transition from the inflammatory to the proliferative phase of healing. In vitro studies indicate that silver nanoparticles enhance the proliferation and migration of keratinocytes and fibroblasts [21], directly accelerating re-epithelialization and granulation tissue formation. The primary endpoint of this study, complete epithelialization, a smooth wound surface upon digital examination, and the absence of pain and bleeding, directly indicates the completion of the proliferative-remodeling phase.

In contrast to the traditional Vaseline gauze, which was prone to dislodgement and resulted in repeated wound exposure, the silver ion dressing remained securely adherent for over 8 h and permitted convenient patient self-replacement. This maintains a stable, moist, and clean wound environment, consistent with moist wound healing theory [22], thereby promoting growth factor diffusion and reducing tissue necrosis.

These findings suggest that silver-ion dressings hold significant potential in perianal wound care. While several studies have demonstrated the efficacy of silver-containing dressings in various wound types, few have specifically examined their application in post-hemorrhoidectomy wounds. This study adds to the growing body of evidence supporting the use of silver-ion dressings as an effective alternative to traditional methods in this specific context.

While we did not observe statistically significant differences in wound infection rates, positive bacterial culture rates, or wound pain levels between the two groups, this should be interpreted with caution. The already low infection rates in both groups might have limited our ability to detect a significant difference. It’s also possible that the VAS scale, while widely used, may not be sensitive enough to capture subtle variations in pain perception. Despite standardized postoperative analgesia at both centers, inter-individual variations in analgesic requirements may represent a confounding factor. Furthermore, factors such as individual pain thresholds and variations in surgical technique across the two centers could have influenced these outcomes. Further studies employing more sensitive pain assessment tools and stratifying patients based on surgical technique may provide a more nuanced understanding of the impact of silver-ion dressings on postoperative pain.

We employed standardized scoring criteria to evaluate anal edema and a dedicated scoring system for dressing performance. No significant differences in anal edema scores were observed between the experimental and control groups. However, patients reported that silver-ion dressings were “more convenient to use.” Specifically, patients noted that the silver-ion dressings were easier to apply and less likely to adhere to the wound, leading to less discomfort during dressing changes. This ease of use could translate to improved patient adherence to the prescribed wound care regimen.

Regarding safety, no adverse events were reported throughout the study, and no statistically significant changes in preoperative and postoperative laboratory tests (CBC, urinalysis, liver/kidney function) were observed. The laboratory parameters were analyzed as dichotomous outcomes (normal vs. abnormal based on reference ranges). This dichotomization may have reduced the sensitivity to detect subtle, clinically relevant changes in laboratory values. Nevertheless, this data still supported the safety profile of the novel dressing. However, it’s important to acknowledge that our safety evaluation was limited to these specific parameters. Long-term effects and potential allergic reactions were not assessed in this study.

Although the acquisition cost of silver-ion dressings is higher than that of Vaseline gauze, the associated reduction in healing time may lower overall costs by decreasing the need for dressing changes and reducing productivity losses. Nevertheless, the definitive cost-effectiveness of this approach requires confirmation through prospective health-economic analyses within large-scale trials.

This prospective, dual-center, randomized trial demonstrated that silver-ion dressings offer advantages in shortening the healing time of perianal wounds. However, our study has limitations. The open-label design constitutes the primary study limitation. The distinct appearance of the dressings prevented blinding of investigators and participants, potentially introducing assessment bias in subjective endpoints like pain scores and patient satisfaction. Future trials should employ placebo dressings with identical appearance to facilitate proper double-blinding. The sample size calculation was based exclusively on the primary outcome of healing time. Consequently, the study was likely underpowered to detect statistically significant differences in secondary outcomes such as pain and edema. The non-significant difference in VAS pain scores (p = 0.766) may represent a clinically relevant effect that lacked statistical power, requiring validation in larger cohorts. Second, follow-up was terminated upon wound healing (median duration: 3–4 weeks). Thus, long-term outcomes including anal stenosis, recurrence, chronic pain, and potential silver ion accumulation were not evaluated. Additionally, safety assessment relied primarily on routine laboratory parameters. Finally, potential confounders including postoperative diet, bowel habits, and concomitant medications were not systematically documented. Mechanistic interpretations regarding the dressing’s mode of action derive mainly from existing literature, since direct measurements of local cytokine profiles or wound microecology were not conducted. These aspects require further investigation in more comprehensive studies.

Therefore, future studies with larger sample sizes, more research centers, and longer follow-up periods are needed to validate our findings, explore the mechanisms of action of silver-ion dressings in post-hemorrhoidectomy wound healing, and assess their long-term safety and efficacy. Future studies should evaluate the efficacy of silver-ion dressings across various hemorrhoidectomy techniques and other contaminated wound types. Specifically, future research should focus on comparing silver-ion dressings with other advanced wound care modalities and evaluating their cost-effectiveness in routine clinical practice.

Conclusion

This prospective, dual-center, randomized trial provides evidence that silver-ion dressings significantly reduce wound healing time and enhance patients’ dressing-change experience following hemorrhoidectomy. By shortening the healing period and offering a more convenient wound care option, silver-ion dressings represent a valuable tool for enhancing postoperative recovery in patients undergoing hemorrhoid surgery. While further research is needed to fully elucidate the mechanisms of action, assess long-term outcomes, and compare their cost-effectiveness against other advanced wound care modalities, our findings support the adoption of silver-ion dressings as an effective and safe alternative to traditional wound care methods in this specific clinical setting.

Authors’ contributions

Study conception and design were performed by Yonghui Su, Yun Liang. All authors contributed to data collection. Analysis of data and writing draft of the manuscript was by Yun Liang. All authors read and approved the final manuscript.

Funding

2024 Zhuhai Municipal Science and Technology Program for Social Development (2420004000273); Guangdong Provincial Medical Science and Technology Research Fund Program (A2025254). The Science and Technology Development Fund of the Macao SAR (0004/2021/AKP).

Data availability

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.

Declarations

Ethics approval and consent to participate

The Institutional Review Board of the Fifth Affiliated Hospital of Sun Yat-sen University and Shenzhen Second People’s Hospital approved this study. This study adhered to the principles of the Declaration of Helsinki and was approved and registered by the Chinese Clinical Trial Center. Written informed consent was obtained from all participants before the commencement of treatment.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.