A novel zipper device versus sutures for wound closure after surgery: a systematic review and meta‐analysis

Abstract

We performed an updated meta‐analysis to compare the efficacy of the zipper device and sutures for wound closure after surgery. A computerised literature search was performed for published trials in PubMed, Web of Science, the Cochrane Library, and Google Scholar. Two reviewers independently scrutinised the trials, extracted data, and assessed the quality of trials. The primary outcome was surgical site infections (SSI). The secondary outcomes were wound dehiscence, total wound complications, wound closure time, and scar score. Statistical analysis was performed in the Stata 12.0. Of the 130 citations, eight trials (1207 participants) met eligibility criteria and were included. The zipper device achieved a lower SSI rate (RR: 0.63, [95% CI: 0.41‐0.96, P = 0.032]), a shorter wound closure time (SMD: −8.53 [95% CI: −11.93 to −5.13, P = 0.000]) and a better scar score (SMD: 0.42 [95% CI: 0.22‐0.62, P = 0.000]) than sutures. No significant difference was shown in the incidence of wound dehiscence and total wound complications. Therefore, the zipper device provides the advantages of anti‐infection, time‐saving, and cosmesis for wound closure.

1. INTRODUCTION

It is estimated that 312.9 million operations are performed every year worldwide. ¹ Skin closure is an integral step of operation that influences cosmesis and satisfaction, and is associated with the absence or presence of wound complications. Surgical wound complications such as surgical site infections (SSI) increase use of antibiotics and revision surgery, lead to prolonged hospital stays and readmission, and increased healthcare costs. ² , ³ , ⁴ Meanwhile, unsightly scars will cause significant undesired physiological and psychological effects if wound do not heal correctly.

The goals of wound closure are to enable rapid skin healing and prevent infection, and to facilitate early mobilisation while achieving a good cosmetic result. A variety of materials including sutures, skin staples, tissue adhesives, and surgical tapes have been used in surgical wound closure. ⁵ Sutures and staples are most commonly used, but staples can cause infections, bleed, additional dress, or scar formation on piercing sites after removed. ⁶ Furthermore, current evidence indicates the risk of postoperative infection is not lower with sutures than staples for skin closure. ⁷

Recently, a novel atraumatic, noninvasive zipper surgical wound closure device has become popular in orthopaedic and cardiothoracic surgical procedures. ⁶ , ⁸ , ⁹ , ¹⁰ It is sterile, adjustable, hydrocolloid adhesive‐based, and designed to replace staples and sutures for closure of the superficial skin layer, which can be applied directly to intact skin on either side of the incision and provides uniform force along the wound edge. ⁸ The similar incidence of SSI between the zipper and sutures was reported. ⁵ , ¹¹ Two previous meta‐analyses of randomised controlled trials (RCTs) on this topic have been published in 2016 and 2020, respectively. ⁵ , ¹¹ However, both were limited by small sample sizes with very low‐certainty evidence. Consequently, we perform an updated meta‐analysis by combining five RCTs ¹² , ¹³ , ¹⁴ , ¹⁵ , ¹⁶ from prior meta‐analyses and three additional studies ¹⁷ , ¹⁸ , ¹⁹ (two RCTs) in order to clarify the state of the evidence. Furthermore, we also attempted to illuminate the limitations of current studies and to provide suggestions for further studies.

2. MATERIALS AND METHODS

This systematic review and meta‐analysis was based on the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) 2009 guidelines. ²⁰

2.1. Literature search

We systematically searched major databases including PubMed, Web of Science, the Cochrane Library, and Google Scholar using the free text terms “zip,” “zipper,” “Medizip,” “suture,” from January 2000 to May 2020 and identified all potentially relevant articles. The search strategies were adjusted to each database. Furthermore, we searched the list of references for the full‐text literature to identify additional eligible trials.

2.2. Eligibility criteria and exclusion criteria

Based on the PICOS strategy to include eligible trials: (a) population (P): patients undergoing surgery with clean surgical wounds; (b) intervention (I): zipper; (c) comparison (C): suture; (d) outcomes (O): not limited; and (e) study design (S): randomised controlled trial or nonrandomised controlled trial. And exclusion criteria were as follow: (a) involving other closure materials (stapler, barbed sutures)in the control group; (b) the reported data were clearly erroneous or incomplete; (c) language is not English; (d) literature is duplicated or cannot get full‐text; and (e) non‐human studies.

2.3. Primary and secondary outcomes

The primary outcome was SSI. Secondary outcomes were wound dehiscence, total wound complications, wound closure time in the operation (minutes), and scar score. SSI was defined as either superficial or deep infections localised to the surgical site, and occur within 30 days after the operation. ³

2.4. Data extraction

Two reviewers independently extracted data and any disagreements were resolved by a third reviewer. Variables used were name of the first author, year of publication, location of the study, study design, date of study period, surgery type, demographic characteristics (number, sex, age, BMI), follow‐up, outcome measures, wound characteristics (location, length), wound closure material and removal time.

2.5. Assessment of risk of bias

We evaluated the risks of bias of the included trials according to the Cochrane Handbook for Systematic Reviews of Interventions. ²¹ Study quality of RCTs was assessed in the Review Manager (RevMan version 5.1), including random generation, allocation concealment, blindness of patients and personnel, blindness of outcome estimators, incomplete outcome data, selective reporting, and other bias. The nine‐star Newcastle‐Ottawa Scale (NOS) was used to evaluate the quality of non‐randomized studies. ²² The scores of the items identifying study quality varied from zero to nine according to the following categories: selection of cohorts (four items), comparability of cohorts (one item), and assessments of outcomes (three items). Any disagreement was settled by a group discussion with a third investigator.

2.6. Statistical analyses

Statistical analysis was performed in the Stata (version 12.0). Heterogeneity between studies was quantified by calculating the I ² statistic. P > 0.1 or I ² < 50% was considered to be no significantly inconsistent and was derived using a fixed‐effects model. Otherwise, a random‐effects model was used. Risk ratio (RR) was calculated for included studies that reported raw counts with 95% confidence interval (CI). The standardised mean difference (SMD) and its 95% CI represent consecutive outcomes results. All P values were two‐sided, and P < 0.05 was considered statistically significant. Finally, removing a trial one by one is used as sensitivity analysis for the robustness assessment of results of meta‐analyses.

3. RESULTS

3.1. Study selection and characteristics

A total of 130 articles were retrieved. After duplicates were removed, we reviewed titles and abstracts of 88 articles, and 70 irrelevant articles were excluded. Then, the full text of the remaining 18 articles was reviewed and evaluated in detail. Finally, eight studies were included in the meta‐analysis (Figure 1).

FIGURE 1.

PRISMA flow diagram of the study selection for the systematic review and meta‐analysis

These studies (seven RCTs and one nonRCT) involved a total of 1207 participants (597 in the zipper group and 610 in the suture group) were published between 2002 and 2019. The baseline characteristics of patients in each trial were similar (Table 1). Wounds from at least five different sites were recorded, and detail of wound closure was listed in Table 2.

TABLE 1.

Characteristics of included studies

Author (year)	Country	Study Design	Study Period	Type of Surgery	Patient Characteristics; Zipper/Suture Group				Duration of Follow‐up	Outcome Measures
					Sample Size	Gender M/F	Mean Age, Years (SD)	Mean BMI (SD)
Roolker (2002)	Netherlands	RCT	November 1996 to February 1998	Orthopaedic surgery	60 60	25/35 20/40	44.9 (16.65) 49.1 (18.27)	NR	6 weeks	① ② ③ ④ ⑤
Risnes (2002)	Norway	RCT	October 1999 to July 2001	Saphenous vein harvesting	78 90	43/125	68.1	NR	6 weeks	②
Risnes (2002)	Norway	RCT	June 2000 to July 2001	Open‐heart surgery	150 150	NR	NR	NR	6 weeks	② ⑤
Onuminya (2006)	Nigeria	RCT	March 2004 to February 2005	NR	50 50	37/13 37/13	35 35	NR	NR	① ② ③
Xu (2014)	China	RCT	July 2011 to June 2012	Posterior spinal fusion surgery	45 45	NR	13.2 (1.6) 13.5 (2.1)	17.8 (3.5) 17.2 (4.2)	1 year	① ② ③ ④ ⑤
Lalani (2016)	USA	RCT	August 2014 to May 2015	CIED procedures	21 19	13/8 12/7	71 (14) 70 (15)	27 (5.08) 27 (4.31)	3 months	④
Tanaka (2016)	Japan	RCT	June 2014 to October 2015	Congenital heart operations	F 71 65 R 42 36	38/33 38/27 20/22 17/19	18.6 (36.8) 16.8 (25.3) 30.5 (45.9) 21.6 (19.8)	NR	3 months	① ② ③ ④ ⑤
Koerber (2019)	USA	NonRCT	October 2015 to April 2017	CIED procedures	80 95	43/37 42/53	70.7 (12.7) 65 (13.4)	NR	73.8 ± 54.8 days 221.3 ± 122.7 days	① ② ③ ④

Note: Outcome measures: ① total wound complications; ② surgical site infection; ③ wound dehiscence; ④ wound closure time; ⑤ scar score.

Abbreviations: CIED, cardiac implantable electronic devices; F, first operation group; NR, not report; R, reoperation group; RCT, randomised controlled trial.

TABLE 2.

Details of wound closure

Author (year)	Wound Location	Length of Wound (cm)		Wound Closure Materials		Time for Removal
		Zipper	Sutures	Zipper	Sutures	Zipper	Sutures
Roolker (2002)	Knee, hip and spine	20.5 ± 9.55	18.2 ± 6.98	Medizip, ATRAX, Bermuda	PDS intracutaneous suture	Not opened but removed between 10 and 14 days	Between 10 and 14 days
Risnes (2002)	Leg	2 to 46		Medizip, ATRAX, Bermuda	Poliglecaprone Monocryl 3‐0 intracutaneous suture	Not opened until removal after 12 days	NR
Risnes (2002)	Sternal	NR		Medizip, ATRAX, Bermuda	Poliglecaprone Monocryl 3‐0 intracutaneous suture	Not opened until removal after 12 days	NR
Onuminya (2006)	NR	NR		Medizip, Assal Medical Products, Germany	Conventional nylon suture	Inspected on the 4th, 7th and 14th days, removed when wound had healed	NR
Xu (2014)	Spine	31.2 ± 3.2	32.2 ± 2.2	Surgizip, MediTech Healthcare, Singapore	Monocryl 4‐0 subcuticular suture	Removed on the 7th day	NR
Lalani (2016)	Sternal	4.3	4.3	Zip Surgical Skin Closure, ZipLine Medical, USA	Monocryl or Vicryl 4.0 continuous suture	Remains on the patient for 10 to 14 days	NR
Tanaka (2016)	Sternal	F 10.28 ± 3.58 R 11.33 ± 4.13	9.51 ± 3.74 10.91 ± 4.09	Zip Surgical Skin Closure, ZipLine Medical, USA	5‐0 Prolene continuous subcuticular suture	7 days after the operation	7 days after the operation
Koerber (2019)	Sternal	NR		Zip Surgical Skin Closure, ZipLine Medical, USA	4‐0 Vicryl subcuticular suture	7 to 14 days following the implant	NR

Abbreviations: F, first operation group; NR, not report; R, reoperation group.

3.2. Risk of bias

The bias of the eligible seven RCTs is summarised in Figure 2A. Only three trials reported how they generated random sequences, four trials reported how they concealed allocation, no trial blinded patients and personnel, and two trials blinded evaluators. As illustrated in Figure 2B, the risk of biases of these selected studies was a bit high. The quality of only one nonRCT (retrospective cohort study) was evaluated according to the NOS. The selection scores, comparability scores, and assessment scores was three, two, and three, respectively. A total score of eight indicate that the quality of the article is good.

FIGURE 2.

Results of the quality assessment for RCTs. (A) Summary of the risk bias; (B) Graph of the risk bias

3.3. Primary outcomes

The pooled results derived from the fixed‐effects model are presented in Figure 3. Seven trials (one excluded) involving 1167 patients reported data for the surgical site infection and the results indicated no significant statistical heterogeneity between the trials (I ² = 22.3%, P = 0.266). The pooled RR was 0.63 (95% CI = 0.41‐0.96, P = 0.032) indicated zipper decreased the incidence of surgical site infection compared with suture.

FIGURE 3.

Forest plot of the surgical site infection rate

3.4. Secondary outcomes

Wound dehiscence was reported in five studies (one excluded) involving 699 patients. Figure 4 showed no significant statistical heterogeneity between the studies (I ² = 34.9%, P = 0.203) and the pooled RR was 0.66 (95% CI = 0.27‐1.59, P = 0.354). Compared with suture, zipper did not decrease the incidence of wound dehiscence. Five studies involving 699 patients reported total wound complications. The pooled result derived from the random‐effects model is presented in Figure 5. The pooled RR was 0.62 (95% CI = 0.15‐2.53, P = 0.502) indicated no significant difference in the incidence of total wound complications between two groups. Five trials involving 639 patients reported data for the wound closure time. Figure 6 shows the pooled result derived from the random‐effects model, the pooled SMD was −8.53 (95% CI = −11.93 to −5.13, P = 0.000). Thus, the application of zipper significantly shortened the time of wound closure compared with that of closure. Four studies provided detailed data of scar score for cosmesis. Given that different rating scales were adopted among the studies, the pooled results were showed in two forest plots (Figure 7: low score representing satisfaction; Figure 8: low score representing dissatisfaction). Figures 7 and 8 show the pooled SMD was −0.72 (95% CI = −1.55 to 0.11, P = 0.09) and 0.42 (95% CI = 0.22‐0.62, P = 0.000) and it is easily found the zipper has tendency to a better cosmetic result in forest plots.

FIGURE 4.

Forest plot of the wound dehiscence rate

FIGURE 5.

Forest plot of the total wound complications rate

FIGURE 6.

Forest plot of the wound closure time

FIGURE 7.

Forest plot of the scar score (low score representing satisfaction). (a) first operation group; (b) reoperation group

FIGURE 8.

Forest plot of the scar score (low score representing dissatisfaction)

3.5. Sensitivity analyses

Figures 5 to 7 show significant heterogeneity in total wound complications (I ² = 75.7%, P = 0.002), wound closure time (I ² = 99.1%, P = 0.000), and scar score (I ² = 92.4%, P = 0.000), respectively. Thus, sensitivity analysis was performed by removing one trial from the pooled analysis each time. We found that all RRs, SMDs, and 95% CIs did not significantly change, indicating the conclusion was relatively robust.

4. DISCUSSION

SSI is a serious complication occurring after surgical operations. In USA, SSI is the most common (31%) healthcare‐associated infection. ²³ Although several meta‐analyses had attempted to clarify the differential SSI risk between skin closure modalities, an ideal modality with both anti‐infection and cosmesis effects remains uncertainly as wound cosmesis is currently considered more important than it was previously. ⁵ , ⁷ , ¹¹ , ²⁴ Tissue adhesives may provide a better cosmetic result but they are used less widespread due to the problems with wound dehiscence. A novel zipper skin closure device has been developed to overcome these problems, but no significantly difference of SSI between the zipper and subcuticular sutures was found in the previous meta‐analyses. ⁵ , ¹¹ In order to expand sample size, a related study published in 2019 ¹⁷ was added, and two additional studies (one adopted conventional nylon suture, ¹⁹ one not mentioned subcuticular ¹⁸ ) were also included in view of the similar incidence of SSI (RR = 1.10, 95% CI = 0.80‐1.52) between subcuticular sutures and transdermal sutures. ⁵ Then, an updated meta‐analysis was performed to clarify the state of the evidence.

The most encouraging finding of current meta‐analysis was that zipper could decrease the incidence of SSI compared with sutures, which is quite different from the results reported in previous meta‐analyses. The sample size in previous studies was too small and the level of evidence was low may be the main cause of this discrepancy. A possible explanation for the great therapeutic effect might be the atraumatic and non‐invasive advantage of zipper in wound closure. The zipper involves no needles and sharps while sutures puncturing the skin and promoting the access of bacteria into the underlying tissue. In addition, bacterial adhere to surgical sutures and protected from phagocytosis are important factors in the development of postoperative wound infection. ¹³ Furthermore, the zipper will not be opened until removal in most cases and the wound being covered until it healed, thus avoid the risk of bacterial contamination at the time of dressing change as the sutures used.

Similar to the results reported in previous meta‐analyses, a shorter wound closure time in the operation and a better scar score (cosmetic result) were also observed. In part, short wound closure time could decrease the risk of surgical‐associated complications and costs. ¹⁴ , ¹⁶ No doubt that suture closure is time‐consuming and requires great skill, but the zipper closure can be applied easily without advanced surgical skills that decrease the technical variation in suturing by different surgeons and promotes standardisation of wound closure. ¹⁰ The patient demand of acquiring good cosmetic appearance of wound closure is commonly. In a study by Levi et al ²⁵ indicated zipper device provides greater shielding of the wound from perturbation caused by distraction forces than sutures. The zipper device provides precise, adjustable, and tension‐free adaptation of the incision edges for a sufficient time and minimal trauma to the skin and underlying tissues, without resulting in an ischemic condition that could impact healing and scarring, thus make it beneficial to a good cosmetic result. ¹⁶ , ²⁶ Several studies reported similar results that a better cosmesis was observed in the zipper group compared with stapler group. ⁶ , ⁸ , ²⁶ Furthermore, a distinctive feature of the zipper was that no need of removing sutures and bandages thus cause less painful, which further improved the patient satisfactions.

The incidence of wound dehiscence and total wound complications were no significant discrepancy between the zipper and sutures in current meta‐analysis. Theoretically, the atraumatic, non‐invasive, and stable mechanical properties of zipper device provides unique benefits for avoiding wound complications. However, complications specific to a new device must be highlighted, including skin peeling, skin discoloration, epidermolysis, blisters, allergic reaction to the adhesive tape area, pruritus in patient with dry skin, and exfoliation of the device. ⁸ , ⁹ , ¹⁵ , ²⁷ Thus, the zipper device need to be further improved in order to overcome these problems.

The choice between the zipper and sutures should be based on factors such as local availability, cost, surgeon preference, and individual constitution and wishes of patients. For example, the zipper device is particularly beneficial for the black race because keloid formation is a common problem among them, and it can also be used on patients with cicatricial skin or who want less scars. ¹⁹ Given the advantages of less pain, making it especially popular in paediatric patients. ¹⁵ The zipper shorten the wound closure time make it provide a unique benefit for patient who cannot tolerate a long period of surgery. For the same reason, in the emergency department, it can not only be used effectively in would closure, but also shorten the waiting time for other patients. ²⁸ In addition, the use of this device is not affected by different surgeons or the length of the wound. ¹⁵ Therefore, it may be a good choice for surgeon who with poor stitching skill and for patient who with long wound. Furthermore, patients have the ability to remove the closure device themselves that highlight the potential clinical and economic utility. ⁹ , ²⁹ Last but not least, the zipper device also reduces the personal risk of injury while stitching or dressing the wound, thus protects surgeon from infectious diseases such as HIV and hepatitis. ¹⁹ In a word, the zipper device provides an inestimable benefit for health care system.

However, the results of this meta‐analysis should be interpreted in light of its limitations. First, the sample size remains insufficient that will decrease the level of evidence. Second, studies exist different degrees of bias risk, most of trials lacking blinding and allocation concealment. Third, potential biases are likely to be greater for a nonRCT was included. Fourth, language limitation to English may weaken the applicability of the conclusions. In addition, different suture types (subcuticular or non‐subcuticular) and materials (absorbable or non‐absorbable) were included together may limit the generalizability of the results. The choice to combine different suture types and materials into one treatment group was because there remains insufficient evidence to suggest that any differences between suture types or materials contribute to differential risk in SSI. The discrepancy between the zipper devices also should be considered, theoretically, a transparent zipper device (Lalani et al, ¹⁸ Tanaka et al ¹⁵ and Koerber et al ¹⁷ ) can be more conducive to wound inspection and avoid the development of complications in time than opaque device (Roolker et al, ¹⁴ Risnes et al ¹² , ¹³ and Xu et al ¹⁶ ). Also, the discrepancy of incision location and patient baseline data between different studies may affect the convincingness of the results. The true rate of SSI or other complications might be underestimated give that some studies reporting only short‐term follow‐up. Furthermore, cosmetic results were evaluated with different scales. Therefore, the practical outcome should be well documented in more large RCTs. Future studies should be informed by the results of current meta‐analysis to be well designed that ensure low risk of bias across the domains of patient selection, suture materials selection, surveillance for outcomes, and completeness of patient follow‐up. A comparison of the zipper and absorbable suture closure will be a future investigation. When the number of RCTs is sufficient, a new meta‐analysis should be performed to further verify current results, and it is necessary to conduct subgroup analyses according to suture materials, wound location, and surgery type, etc.

5. CONCLUSIONS

Compare with sutures, for the first time, we found the zipper device decreased the incidence of SSI in a relatively large meta‐analysis. The zipper could both shorten wound closure time and improve cosmetic result, but cannot significantly decrease the incidence of wound dehiscence and total wound complications. Thus, the zipper provides the specific advantages of anti‐infection, time‐saving, and cosmesis for wound closure. However, more well‐designed studies are needed to confirm the reliability of these results.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

DISCLOSURE OF INTERESTS

The authors have nothing to disclose.

ETHICS STATEMENT

This article does not contain any studies with human participants or animals performed by any of the authors.

Xie C‐X, Yu C‐Q, Wang W, Wang C‐L, Yin D. A novel zipper device versus sutures for wound closure after surgery: a systematic review and meta‐analysis. Int Wound J. 2020;17:1725–1737. 10.1111/iwj.13460