Vrouwen met obesitas hebben een verhoogd risico op wondcomplicaties na een sectio . Het is onduidelijk of het sluiten van de huid door middel van agraves het risico op complicaties verlaagt, of het genezingsproces verbetert en de of de tevredenheid van de patiënt beter is in vergelijking met doorlopend sluiten van de huid. In de huidige NVOG richtlijn Zwangerschap bij Obesitas 2009  is hierover nog geen aanbeveling gedaan.

Description of studies

Mackeen (2015) is a systematic review and meta-analysis investigating the difference between absorbable suture and metal staples on wound complications, pain perception, patient satisfaction and operating time. The review included all women who received a caesarean section, however not women with obesity in specific. The study included RCTs that compared absorbable suture with non-absorbable staples, excluding all other surgical closure techniques. The study investigated the primary outcome ‘wound complication’ stratified for obesity (BMI <30 kg/m² nonobese vs. ≥30 kg/m² obese). For this, the authors of the trials were contacted to obtain more details about the outcome wound complications stratified by body mass index (<30 kg/m² [nonobese] vs. ≥30 kg/m² [obese]). A total of 5 RCTs provided their wound complication results stratified for obesity, with a total of 627 women receiving sutures and 641 staples (Aabakke, 2013; Basha, 2010; Figueroa, 2013; Huppelschoten, 2013; Mackeen, 2014; Zaki, 2013). The postoperative follow up time to assess wound complications differed from 2-4 weeks to 12 weeks. Wound complications included the assessment of infections (all studies), wound separation (all studies), hematoma (Figueroa, 2013; Huppelschoten, 2013 and Mackeen, 2014), seroma (Figueroa, 2013; Mackeen, 2014) and readmission for wound complications (Basha, 2010) (Table 1). One study investigated suture versus staples by using each method on each lateral side of the incision (Aabakke, 2013). One study included both uterine and wound infections together in their wound infection rate (Basha, 2010).

Table 1. Wound complications reported in individual studies

Source: Mackeen (2015) “a Included uterine infections in definition of infection; b Hematoma and seroma numbers were not presented separately, but included as causes of skin separation”

Zaki (2018) is a RCT performed in the US comparing subcuticular suture with stainless steel staples for wound closure in women with class III obesity (BMI ≥40km/m²). The study randomized 121 women to suture and 121 to staples. All patients underwent a subcutaneous closure before receiving the subcuticular suture or staples. The mean BMI was 45.1 ≥± 4.4 kg/m² in the staples group and 46.2 ± 5.5 kg/m² in the suture group. The primary outcome was ‘wound complications’, defined as infection, superficial separation or deep separation (Table 2).  Wound complications were assessed at hospital discharge and at 2 weeks postpartum. Besides wound complications, the study also assessed total operative time and patient satisfaction (overall and about wound appearance).

Table 2. Wound complications reported in an individual study

Source: Zaki (2018)

Results

The results from the meta-analysis by Mackeen (2015) were only available for the critical outcome ‘1. wound complications’ stratified by obesity. The crucial outcome ‘2. wound infections’ and the other important outcomes were not separately assessed for women with obesity by Mackeen (2015). Therefore, only the individual RCT by Zaki (2018) could be used.

Critical outcomes

1. Wound complications

Mackeen (2015) included 5 trials (1030 women) to compare absorbable suture with staples as a closure technique in women with obesity undergoing a caesarean section. Obesity was defined by Mackeen (2015) as a BMI ≥30m². The working group has added the trial of Zaki (238 women) to this comparison, which compared absorbable suture with stainless steel staples as closure techniques as well, to combine to a total of 6 trials (1268 women). Zaki, 2018  included only women with a body mass index ≥40kg/m². The outcome ‘wound complications’ was defined by the individual trial authors as a composite of wound infection (all studies), separation (all studies), hematoma (Figueroa 2013, Huppelschoten 2013, Mackeen 2014 and Zaki 2018), seroma (Figueroa 2013, Mackeen 2014 and Zaki 2018) and readmission for wound complications (Basha 2010) (Table 1 and 2).

Overall, subcuticular suture reduced the risk of developing a wound complication with 39% compared to staples (6 trials, 1268 women, RR 0.61, 95%CI 0.45 to 0.83). This RR is statistically significant, and pertains a clinically relevant difference as the confidence interval does not exceed the limit of RR≤0.9.

Figure 1. Outcome wound complications, comparison sutures versus staples in women with obesity undergoing a caesarean section

Source: Mackeen, 2015 & Zaki 2018 Z: p-value of the pooled effect; df: degrees of freedom; I²: statistical heterogeneity; CI: confidence interval.

2. Wound infections

Zaki (2018) assessed the outcome ‘wound infection’ in 238 women, comparing absorable sutures with stainless steel staples as a closure technique in women with obesity undergoing a cesarean section. The authors included only women with a body mass index ≥40kg/m². Wound infections were defined as ‘those meeting the Centers for Disease Control and Prevention definition of surgical site infections and requiring antibiotic therapy’, and were assessed at hospital discharge and at two weeks postpartum.

At the postoperative wound inspection (7-14 days post partum) no significant difference in wound infection rate between sutures and staples was reported (Table 3) (Zaki 2018). The clinical relevance of the found effect is unclear, as the confidence interval is exceeding both the upper and lower limit of clinical relevance (RR≤0.75 and RR≥1.25), indicating (large) imprecizion.

Table 3. Wound infection reported in an individual study

Source: Zaki (2018)

Important outcomes

3. Wound separation

Zaki (2018) assessed the outcome ‘wound separation’ in 238 women, comparing absorable sutures with stainless steel staples as a closure technique in women with obesity undergoing a caesarean section. The authors included only women with a body mass index ≥40kg/m². Wound separations were identified as either superficial (<0.5 cm deep and only involving the dermis layer) or deep (>0.5 cm in depth and requiring packing

or reclosure) resulting from hematoma or seroma (Zaki 2018).

At the postoperative wound inspection (7-14 days post partum) no significant difference in superficial or deep separation between sutures and staples was reported (Table 4) (Zaki 2018). The clinical relevance of the found effect is unclear, as the confidence interval is exceeding both the upper and lower limit of clinical relevance (RR≤0.75 and RR≥1.25), indicating (large) imprecizion.

Table 4. Wound separation reported in an individual study

Source: Zaki (2018)

4. Patient satisfaction

Zaki (2018) assessed the outcome ‘patient satisfaction’ in 227 women, comparing absorable sutures with stainless steel staples as a closure technique in women with obesity undergoing a cesarean section. The authors included only women with a body mass index ≥40kg/m². Patient satisfaction consisted of an survey assessment of pain (1=least, 10=most), wound appearance satisfaction (1=least, 10=most), concern about wound healing (1=least, 10=most), wound recovery satisfaction (‘would you have the same closure again’ percentage answering ‘yes’). The assessment was done at the 7-14 day wound follow up visit.

Table 5. Patient satisfaction reported in the individual studies

Source: Zaki (2018). “Data were analyzed with Mann-Whitney U and c2 tests, where applicable. Data are presented as median [interquartile range] or n (%) unless otherwise noted. P value <.05 indicates significance.” *this question was not considered a relevant measure for patient satisfaction by the working group, since complete wound healing occurs after 6-12 months, the results are not representative for wound healing after 7-14 days.

In both groups women were similarly content with the pain level, wound appearance and concern about wound healing (Table 5). However, when women were asked if they would choose the same closure technique again, women with sutures choose significantly more often for the same closure again, which may indicate more wound recovery satisfaction (Table 5) (Zaki, 2018).

5. Duration of hospital stay (days)

Zaki (2018) assessed the outcome ‘duration of hospital stay (days)’ in 238 women, comparing absorable sutures with stainless steel staples as a closure technique in women with obesity undergoing a caesarean section. The authors included only women with a body mass index ≥40kg/m².

No difference between hospital stay was observed between groups, with an average stay of 5 days for both groups (4.9 days in both groups) (Independent samples T-test, p=1.00) (Zaki 2018).

6. Duration of operation / length of procedure (minutes)

Zaki (2018) assessed the outcome ‘length of procedure (minutes)’ in 238 women, comparing absorable sutures with stainless steel staples as a closure technique in women with obesity undergoing a caesarean section. The authors included only women with a body mass index ≥40kg/m².

The length of the procedure was in average 12 minutes longer in the sutures group (55.8±26.0 sutures total procedure, 43.2±21.9 staples total procedure), which was clinically significant (Independent samples T-test, p=0.001) (Zaki, 2018).

7. Thrombosis

None of the included studies reported on the outcome thrombosis.

8. Readmission for wound concern

None of the included studies reported on the outcome readmission for wound concern.

Level of evidence of the literature

The level of evidence regarding the outcome measure ‘1. wound complications’ was not further downgraded, so assessed a high GRADE.

The level of evidence regarding the outcome measure ‘2. wound infections’ was downgraded by 2 levels to a low GRADE because of (large) imprecision (confidence interval exceeds both the lower limit of clinical relevance and upper limit of clinical relevance (RR≤0.75 and RR≥1.25).

The level of evidence regarding the outcome measure ‘3. wound separation’ was downgraded by 2 levels to a low GRADE because of (large) imprecision (confidence interval exceeds both the lower limit of clinical relevance and upper limit of clinical relevance (RR≤0.75 and RR≥1.25).

The level of evidence regarding the outcome measure ‘4. patient satisfaction’ was downgraded by 2 levels to a low GRADE because of imprecision (number of patients <2000) and indirectness of questions asked for actual patient satisfaction.

The level of evidence regarding the outcome measure ‘5. Duration of hospital stay (days)’ was downgraded by 1 level to a moderate GRADE because of imprecision (number of patients <2000).

The level of evidence regarding the outcome measure ‘6. Length of procedure (minutes)’ was downgraded by 1 level to a moderate GRADE because of imprecision (number of patients <2000).

The outcome ‘7. Thrombosis’ could not be GRADED because no studies reported on this outcome.

The outcome ‘8. Readmission for operation’ could not be GRADED because no studies reported on this outcome.

A systematic review of the literature was performed to answer the following question: what is the effect of skin closure with continuous sutures versus staples on wound complications, wound infections, wound separation, patient satisfaction, duration of hospital stay and thrombosis in women with obesity that undergo a caesarean section?

P:           Women with obesity undergoing a cesarean section

I:            Skin closure with staples

C:           Skin closure with continuous sutures

O:          Wound complications (separation of wound edges, seroma,

hematoma), wound infection, patient satisfaction over recovery, patient satisfaction

with scar, duration of hospital stay, duration of operation, thrombosis, readmission

for wound concern

Relevant outcome measures

The guideline development group considered wound complications and wound infections as critical outcome measures for decision making; and patient satisfaction, duration of hospital stay, readmission for wound concern, duration of operation, and thrombosis as important outcome measures for decision making.

A priori, the working group did not define the outcome measures listed above but used the definitions used in the studies.

The working group defined a relative risk difference of 10% (boundaries at 0.90 – 1.10 RR)  as a minimal clinically (patient) important difference for the outcome wound complications. With an absolute risk of approximately 10% the working group considered a number needed to treat of 19 reasonable.

The working group defined a relative risk difference of 25% (boundaries at 0.75 – 1.25 RR)  as a minimal clinically (patient) important difference for all other outcomes.

Search and select (Methods)

The databases Medline (via OVID) and Embase (via Embase.com) were searched with relevant search terms until December 24^th, 2019. The detailed search strategy is depicted under the tab Methods. The systematic literature search resulted in 317 hits. Studies were selected based on the following criteria:

• At least a subgroup analysis specific for obese participants
• A comparison between staples and continuous sutures for skin closure during cesarean section
• Investigated at least one of the outcomes as reported in the PICO
• Involves the original study data

3 studies were initially selected based on title and abstract screening. After reading the full text, 1 study was excluded (see the table with reasons for exclusion under the tab Methods), and 2 studies were included.

Results

Two studies were included in the analysis of the literature. Important study characteristics and results are summarized in the evidence tables. The assessment of the risk of bias is summarized in the risk of bias tables.