Use of Barbed Sutures for Congenital Diaphragmatic Hernia Repair

Background: Congenital diaphragmatic hernia (CDH) repair can be challenging, particularly when a larger defect is present. Barbed sutures prevent the suture from slipping back after approximation of the tissues. Although introduced almost 2 decades ago, barbed sutures have not been widely used for CDH repair. We report our initial experience and pitfalls. Methods: All patients presenting with CDH from 2021 onward underwent repair using barbed sutures. Demographics, operative parameters, complications, and outcomes were prospectively recorded. Results: A total of 13 patients underwent CDH repair during the study interval (median age 6 days, range 3 days to 5.75 years). Median operative time was 89 min (range 46 to 288 min). Five thoracoscopic and eight open procedures were performed. Severe pulmonary hypertension and ECMO (extracorporeal membrane oxygenation) were considered contraindications for thoracoscopic repair. The included patients were compared to a historic controlled group performed without barbed sutures. The barbed suture facilitated easy and quick closure of the defects in most cases and obviated the need for knot tying. One patient in the thoracoscopic group had a patch placed due to high tension after the barbed sutures tore the diaphragm. At a median follow-up time of 15 months (range 2 to 34 months), one patient had died, and one patient with complete diaphragmatic agenesis was home-ventilated. There were no recurrences. Median operative time trended lower (89 min) than in the historic control group repaired without barbed sutures (119 min, p < 0.06) after eliminating outliers with large, complex patch repairs. Conclusions: Barbed sutures simplify congenital diaphragmatic hernia repair regardless of whether a minimal-invasive or open approach is performed. Patch repair is not a contraindication for using barbed sutures. The resulting potential time savings make them particularly useful in patients with cardiac or other severe co-morbidities in which shorter operative times are essential. In cases with high tension, though, the barbs may tear through and produce a “saw” effect on the tissue with subsequent damage.


Introduction
Congenital diaphragmatic hernia (CDH) is a malformation with a wide spectrum of phenotype, presentation, and outcome [1].After cardiopulmonary stabilization, surgical closure of the hernia is indicated but can be challenging.This is particularly true in larger defects, as the resulting tension complicates the procedure.Thoracoscopic repair may convey advantages such as shortened postoperative length of stay [2], but it is technically challenging and considered by some to be associated with longer operative times as well as more pronounced acidosis during the procedure [3].Therefore, technical innovations that simplify the procedure and shorten operative times may help improve outcome.
While there is ample literature on the advantages and disadvantages of thoracoscopic versus open CDH repair [2,3], none of these studies have included the use of barbed sutures.In fact, pediatric surgeons have been very slow to adapt barbed sutures in their armamentarium.This is in contrast to adult surgeons.According to a review of Bishay et al. [3], barbed suture material has been utilized for a wide array of indications, including operations in cosmetic plastic surgery, obstetrics and gynecology, gastrointestinal surgery as well as orthopedic surgery.The authors conclude that barbed sutures present an innovative and effective alternative to conventional surgical sutures [3].Barbed sutures were also used in pediatric urology.A recent systematic review comparing barbed versus conventional sutures of five studies showed significant shorter operative times when barbed sutures were used [4].
Barbed sutures feature small nicks or hooks along a monofilament thread that prevent it from slipping back after pulling them through the tissues [5].Therefore, they do not need to be knot tied for secure tissue apposition after typically completing a running stitch.These physical features facilitate the approximation of tissues under a moderate amount of tension, making barbed sutures particularly useful for diaphragmatic hernia repair.Although barbed sutures have been introduced almost two decades ago [6], they have not been widely used for CDH repair.In fact, only one published case series on the topic is available in the medical literature [7].This study reports our initial experience on CDH repair using barbed sutures and the pitfalls we encountered.

Study Design
All patients presenting with CDH to our department from February 2021 through October 2023 underwent repair using barbed sutures.Demographics, operative parameters, complications, and outcomes were recorded in a registry and later analyzed.The operative time as the primary outcome parameter was statistically compared to a historic control group.All other parameters were defined as secondary measures, which were reported using descriptive statistics in terms of frequency, median and range, and statistically compared.

Patient Selection
All consecutive patients with CDH were included.Co-morbidities and the use of extracorporeal membrane oxygenation (ECMO) were not considered reasons for exclusion.This study also included patients that underwent thoracoscopic hernia repair as well as patients that were operated with an open technique (by laparotomy).In our center, severe pulmonary hypertension and having been treated with ECMO are considered contraindications for a thoracoscopic repair.

Suture Material
The operations were conducted using barbed sutures of 2 different manufacturers (Figure 1).This suture material can be best described as a microfilament suture with barbs or leaflets on its surface allowing for a knotless surgery.The barbs slip through the tissue in an antegrade fashion but hook into the tissue to prevent retrograde pulling through.Thereby, the suture is locked in place.Thus, the need to tie a final knot is eliminated.

Open Repair
Open repairs were always completed via a subcostal laparotomy.The infant is placed in a supine position.Subsequently, the abdomen is opened and any abdominal organs that have advanced into the chest cavity are reduced into the abdomen.In the event of a hernia sac, it is resected.After fully exposing and identifying the area of defect, it is categorized according to size (A (small defect) to D (complete absence of the diaphragm), according to Lally et al. [8]).If the size of the defect allows, the defect margins are approximated and closed using barbed sutures.The abdomen is closed in layers.

Open repair
Open repairs were always completed via a subcostal laparotomy.The infa in a supine position.Subsequently, the abdomen is opened and any abdom that have advanced into the chest cavity are reduced into the abdomen.In th hernia sac, it is resected.After fully exposing and identifying the area of categorized according to size (A (small defect) to D (complete absence of the d according to Lally et al. [8]).If the size of the defect allows, the defect m approximated and closed using barbed sutures.The abdomen is closed in lay 2.4.2.Thoracoscopic Repair During a thoracoscopic repair of CDH, the child is positioned in a latera position with the affected side's arm raised up over the shoulders.A 3 m advanced into the fourth intercostal space in the mid-axillary line.The cap insufflated at a pressure of PEEP + 1 mmHg and a flow of 1-3 L/minute.Un two more 3 mm trocars are placed anterior and posterior to the first trocar.organs that have herniated into the thoracic cavity are returned to their origi using the intrathoracic pressure and reverse Trendelenburg as well as gentl with a blunt thoracoscopic grasper.If a hernia sac is present, it is pushed ba abdomen and resected.After the defect margins are identified, the transition pleura and peritoneum is freshened up using monopolar for improved wou and barbed sutures are utilized to close the diaphragmatic defect (Figure Supplementary Materials).The instruments are retracted and the wounds Trocars were then retracted.A chest tube may be left postoperatively.

Thoracoscopic Repair
During a thoracoscopic repair of CDH, the child is positioned in a lateral decubitus position with the affected side's arm raised up over the shoulders.A 3 mm trocar is advanced into the fourth intercostal space in the mid-axillary line.The capnothorax is insufflated at a pressure of PEEP + 1 mmHg and a flow of 1-3 L/minute.Under vision, two more 3 mm trocars are placed anterior and posterior to the first trocar.Abdominal organs that have herniated into the thoracic cavity are returned to their original location using the intrathoracic pressure and reverse Trendelenburg as well as gentle reduction with a blunt thoracoscopic grasper.If a hernia sac is present, it is pushed back into the abdomen and resected.After the defect margins are identified, the transition of parietal pleura and peritoneum is freshened up using monopolar for improved wound healing, and barbed sutures are utilized to close the diaphragmatic defect (Figure 2; Video in Supplementary Materials).The instruments are retracted and the wounds are closed.Trocars were then retracted.A chest tube may be left postoperatively.

Figure 1.
Sutures used in this study.The V-Loc TM (Medtronic GmbH, Meerbusch, Germany) s (a) has small spiral spikes that prevent backslipping of the suture, while the Quill TM (Corza Me GmbH, Zurich, Switzerland), suture (b) features small spiral oblique cut-in leaflets that act i same manner (see magnified inlays).

Open repair
Open repairs were always completed via a subcostal laparotomy.The infant is pl in a supine position.Subsequently, the abdomen is opened and any abdominal or that have advanced into the chest cavity are reduced into the abdomen.In the event hernia sac, it is resected.After fully exposing and identifying the area of defect, categorized according to size (A (small defect) to D (complete absence of the diaphra according to Lally et al. [8]).If the size of the defect allows, the defect margins approximated and closed using barbed sutures.The abdomen is closed in layers.

Thoracoscopic Repair
During a thoracoscopic repair of CDH, the child is positioned in a lateral decu position with the affected side's arm raised up over the shoulders.A 3 mm troc advanced into the fourth intercostal space in the mid-axillary line.The capnothor insufflated at a pressure of PEEP + 1 mmHg and a flow of 1-3 L/minute.Under vi two more 3 mm trocars are placed anterior and posterior to the first trocar.Abdom organs that have herniated into the thoracic cavity are returned to their original loca using the intrathoracic pressure and reverse Trendelenburg as well as gentle redu with a blunt thoracoscopic grasper.If a hernia sac is present, it is pushed back into abdomen and resected.After the defect margins are identified, the transition of par pleura and peritoneum is freshened up using monopolar for improved wound hea and barbed sutures are utilized to close the diaphragmatic defect (Figure 2; Vide Supplementary Materials).The instruments are retracted and the wounds are clo Trocars were then retracted.A chest tube may be left postoperatively.

Patch Repair
Some patients required a patch repair in cases when the diaphramatic defect was so large that the margins could not be approximated primarily.There were 2 types of patches available, consisting of polytetrafluoroethylene (PTFE, GoreTex TM ; W.L. Gore & Associates, Inc, Barcelona, Spain) or collagen (human decellularized collagen, Epiflex TM ; DIZG.Gemeinnützige GmbH, Berlin, Germany).The patch is generously cut to cover the entire area of the defect.To allow for growth, extra patch material is left on the margins.
Regardless of closure type, a radiograph is performed to verify adequate repair of the defect (Figure 3).
available, consisting of polytetrafluoroethylene (PTFE, GoreTex ; W.L. Associates, Inc, Barcelona, Spain) or collagen (human decellularized collagen, E DIZG.Gemeinnützige GmbH, Berlin, Germany).The patch is generously cut to c entire area of the defect.To allow for growth, extra patch material is left on the m Regardless of closure type, a radiograph is performed to verify adequate repa defect (Figure 3).

Consent and Ethics
Consent for participation was obtained by all families.Ethical approval for r the series was obtained from our institutional ethics board (registration number 2

Historic Control Group and Statistical Comparison
The last 13 consecutive cases of CDH repair performed in the institution barbed sutures were compiled and statistically compared with the barbed sutur Metric parameters were analyzed using the Mann-Whitney U-test, and dicho parameters were analyzed using the Chi-square test.A p < 0.05 was considered sig while a p < 0.10 was considered a trend.Statistics were calculated using DATAtab s

Demographic Information of the Patients
Demographic data are presented in the left columns of Table 1.A tot consecutive patients underwent CDH repair in the study interval.Our study co nine male and four female patients.The median gestational age at birth was 3 (range 33 to 40 weeks).The median weight at birth was 2960 g (range 1950 to 4 the time of birth.Ninety-two percent of the patients were diagnosed with co-mor including bilateral vesico-uretero-renaler reflux (VUR), pulmonary hyp pulmonary hypertension, pulmonary atresia, systemic-pulmonary shunt, and co heart defects.One patient presented with volvulus based on malrotation at the surgery, one older patient presented with recurrent pneumonia.In ten patients, was located in the chest cavity ("liver-up").Four patients had been treated with prior to CDH repair.

Consent and Ethics
Consent for participation was obtained by all families.Ethical approval for reporting the series was obtained from our institutional ethics board (registration number 23-0881).

Historic Control Group and Statistical Comparison
The last 13 consecutive cases of CDH repair performed in the institution without barbed sutures were compiled and statistically compared with the barbed suture group.Metric parameters were analyzed using the Mann-Whitney U-test, and dichotomous parameters were analyzed using the Chi-square test.A p < 0.05 was considered significant, while a p < 0.10 was considered a trend.Statistics were calculated using DATAtab statistics.

Demographic Information of the Patients
Demographic data are presented in the left columns of Table 1.A total of 13 consecutive patients underwent CDH repair in the study interval.Our study comprises nine male and four female patients.The median gestational age at birth was 38 weeks (range 33 to 40 weeks).The median weight at birth was 2960 g (range 1950 to 4270 g) at the time of birth.Ninety-two percent of the patients were diagnosed with co-morbidities, including bilateral vesico-uretero-renaler reflux (VUR), pulmonary hyperplasia, pulmonary hypertension, pulmonary atresia, systemic-pulmonary shunt, and congenital heart defects.One patient presented with volvulus based on malrotation at the time of surgery, one older patient presented with recurrent pneumonia.In ten patients, the liver was located in the chest cavity ("liver-up").Four patients had been treated with ECMO prior to CDH repair.Abbreviations: ASD-atrial septal defect; CDH-congenital diaphragmatic hernia; CVL-central venous line; Lap-laparoscopic; NO-nitric oxide; PDA-patent ductus arteriosus; PTFE-perfluorotetraethylene; SGA-small for gestational age; s/p-status post; VSD-ventricular septal defect; VUR-vesicoureteral reflux; wks-weeks; VA ECMO-venoarterious extracorporeal membrane oxygenation.

Intraoperative Parameters
Table 1 also shows peri-and postoperative outcome parameters of the patients.The median age at the time of operation was 6 days (range 3 days to 5.75 years).The median weight at operation was 3140 g (range 1910 g to 30 kg).Five children underwent thoracoscopic repair, and the other eight underwent open repair via laparotomy.Five patients presented with a right-sided defect.Our study comprises of one type A, seven type B, three type C and two type D CDHs.One patient in the thoracoscopic group and four patients in the laparotomy group had a patch placed.In the thoracoscopic case, the patch was not planned: After attempting a primary repair with barbed sutures, high tension led to a pull-back of the suture against the barbs.These tore the diaphragmatic tissue by a sawing effect of the barbs, representing the only perioperative complication.The median operative time was 89 min (range 46 to 288 min).

Complications and Outcomes
The right-sided columns of Table 1 give an overview of all complications and outcomes.The median postoperative length of stay was 30 days (range 3 to 139 days).At a median follow-up time of 15 months (range 2 to 34 months), one patient had died due to pulmonary hypoplasia and a clotted systemic-pulmonary shunt (mortality 8%), and one patient with complete diaphragmatic agenesis was home ventilated via tracheostomy.There were no recurrences of the CDH, and three patients with larger defects had gastroesophageal reflux requiring proton-pump therapy.One child developed a necrotizing enterocolitis postoperatively that was treated with antibiotics alone (Bell stage IIb).Another was treated with antibiotics due to a central venous line sepsis.One of the infants developed pneumonia seven weeks after the operative procedure, which also required treatment with antibiotics.

Comparison to the Historic Control Group
All parameters of the control group are presented in Table 2.Although the median operative time was lower (89 min) in the barbed group compared to controls (119) minutes, this difference did not reach statistical significance in the Mann-Whitney U-test (p = 0.24) when considering all patients.The box plot of operative times in Figure 4 shows two substantial outliers in the barbed suture group.These two patients were associated with complex patch reconstructions of large diaphragmatic defects.There were no comparable cases in the control group.When eliminating these two outliers from the statistical comparison, operative times trended shorter in the barbed suture group (p = 0.06).Overall, there were more overall patch repairs in the barbed suture group (p = 0.05).Gestational age in the barbed suture group trended lower as well.Abbreviations: wks-weeks; VUR-vesicoureteral reflux; PDA-patent ductus arteriosus; PFO-patent foramen ovale, VSD-ventricular septal defect; ASD-atrial septal defect, SGA-small for gestational age; s/p-status post; NO-nitric oxide; VA ECMO-venoarterious extracorporeal membrane oxygenation, CDH-congenital diaphragmatic hernia, PTFE-perfluorotetraethylene, LTFO-lost to follow up.which had large defects that required a complex patch repair.After eliminating the 2 outliers from the calculation, a trend toward shorter operative times in the barbed suture group was evident (p = 0.06).

Discussion
Our series represents the largest comprehensive study on consecutive patients who underwent barbed suture repair of congenital diaphragmatic hernia repair across both open and minimal-invasive techniques.
Thus far, most scientific research on CDH repair in infants focuses on the differences between the thoracoscopic and open methods [2,3,9].Barbed sutures have been used for cruroplasty and hiatal hernia closure in adults [10].However, they are strikingly absent from the discussion in pediatric surgery.Even research that could potentially be used in the development of future guidelines makes no mention of barbed suture material [1].Hence, the use of barbed sutures is vastly undervalued and not yet ascertained in the field of pediatric surgery.
There is only one other case series that explores the use of barbed sutures for CDH repair in infants and children, which was published by Lukish et al. [7].In this case series, eleven patients underwent a minimally invasive diaphragmatic hernia repair (thoracoscopic or laparoscopic) with barbed sutures.In contrast, our patients were operated thoracoscopically or open via laparotomy.Therefore, this is the first series of open CDH repair using barbed sutures.In the previous series [7], 19 percent of patients developed a recurrence, primarily the ones in which absorbable sutures were used.None of our patients had a recurrence.After the initial two patients, we performed all operations using non-absorbable, permanent sutures.In the first two, we intraoperatively resected the hernia sac and freshened up the margins of the defect with the intention that the tissues would heal.Neither one had a recurrence after 30 and 31 months of follow-up.
In the Lukish study [7], none of the other nine patients suffered from complications or mortality.On the other hand, one of our patients died of complications resulting from pulmonary atresia that was treated by cardiac surgery and a systemic pulmonary shunt.Upon autopsy, acute clotting of the shunt was discovered as the probable cause of death.Considering that our cohort was a consecutive, non-selected cohort including some very ill neonates, and out of which four patients were treated with ECMO, mortality actually was quite low.
Lukish et al. [7] emphasized that the "barbed suture is an innovative, safe and timesaving option" for pediatric Our findings corroborate this conclusion.They also stress that further prospective analyses with long-term follow-ups are required to confirm the initial results and success with the barbed suture method.
Because of the heterogeneous presentation of CDH, it is difficult to establish an internal control group.However, our study implies that the operative time may potentially be reduced through the use of barbed suture material.We reported a median operative time of 89 min (range 46 to 288 min).In comparison, the median operative time with conventional suture material (not using barbed suture) was reported as 102 min for a thoracoscopic repair and 129 min for an open repair in a recent study [9].In our analysis, the median operative time for barbed suture CDH repair trended lower compared to the operative time of the historic control group.Because CDH is a rare disease, it was not possible to do a matched-pair analysis, since every patient with CDH is different and has their own characteristics and co-morbidities.Operative time, however, is an objective parameter and therefore chosen as the primary outcome parameter.It is independent of most comorbidities and mostly influenced by technical factors, such as the type of suture employed.Therefore, the main take-home message of this study is that barbed sutures may shorten operative time of CDH repair.
Regarding the comparison of operative times between groups, the lack of significance is mainly driven by two outliers in the barbed group (patients 6 and 8), who had operations that took 288 and 200 min to complete.Both patients had large (type C and D) defects and required a complex patch repair.The box plot of operative times (Figure 4) illustrates the effect of the outliers.For correct interpretation of the operative times, it is important to note that there was a trend toward more patch repairs and lower gestational age in the barbed suture group, potentially complicating and thereby protracting the operation.
The potential reduction in operative time is most likely attributed to an easier closure without the need for intracorporeal or open knot tying.This method simply allows for a faster and easier closure.This is particularly beneficial if the physiology is tenuous, for example in premature infants with low body weight or patients with complex comorbidities.We believe that larger patient groups and sample sizes will eventually show superiority of the barbed suture in terms of operative times.
In addition, our findings indicate that the recurrence rate may be reduced through the use of barbed suture material, especially if permanent non-absorbable suture material is used.There were no recurrences in our series of 12 patients.A systematic review on CDH repair using conventional sutures showed a 8.6 percent recurrence rate for thoracoscopic repair and a 1.6% recurrence rate for open repair [11].Nevertheless, it must be noted that the only other case series on barbed suture CDH repair reports a 19% recurrence rate [7].Obviously, the small sample size substantially limits adequate judgment at this time.
The median length of hospital stay in our series was not shorter than reported in the literature.While we report a median hospital stay of 30 days (range 3 to 139 days), it was 13 days for thoracoscopic repair and 19 days for open repair in a recent report [9].However, it must be noted that the vast majority of our patients presented with multiple co-morbidities, many of them complex.Thus, the increased length in hospital stay most likely cannot be attributed to the barbed suture method but rather to a range of health issues.Likewise, the survival rate of 92% in our study compares closely to the survival rate in recent studies [9,11].
Overall, the barbed suture method for CDH repair has few disadvantages.The higher cost associated with barbed suture material (3 to 4-fold of conventional sutures at our institution, around €40 for a barbed suture instead of €12 for a conventional suture) might deter some surgeons from using it, although it is negligible when considering the overall hospital cost of treating a CDH patient.In fact, several studies have shown actually decreased total hospital costs when barbed sutures were used for a variety of different indications [12][13][14].
A definitive pitfall to avoid is the use when tension is too high for the barbed sutures to hold.In that case, the barbed suture slips back through the tissue, and the barbs tear the tissue by a saw effect.This was the case in patient 5. Therefore, barbed sutures are more suitable for cases with low to medium tension.If the defect is too large, a patch repair should be performed.The patch can be fixed to the surrounding edges or the thoracic wall using barbed sutures.
Small bowel obstruction by a lose end of the barbed suture is the most severe complication after use of bowel sutures [15][16][17][18].The risk can be minimized by leaving a small tail.We usually complete a running barbed suture by making one to two locking loops that prevent the backslip of short suture ends.
Our findings are bound by certain limitations.This study comprises a limited number of cases.The retrospective nature of the study is also a limitation.Additional prospective research with a larger pool of patients and longer follow-ups is warranted for a more precise understanding of the advantages and disadvantages of the barbed suture method in CDH repair.

Conclusions
Our study indicates that barbed sutures can facilitate the repair of congenital diaphragmatic hernia.They are applicable for both thoracoscopic and open procedures as well as for patch repair.Obviating the need for knot tying may shorten operative times, making barbed sutures particularly useful for CDH repair in infants with tenuous physiology and for minimal-invasive repair.To lower the risk of recurrence, non-absorbable barbed sutures should be used exclusively.More comparative studies are required to objectify the advantages of barbed sutures for CDH repair.Ideally, a randomized controlled trial of barbed versus conventional sutures should be performed with the outcome parameters described in our study.Because CDH is a rare and heterogeneous malformation, a multi-center study approach with a standardized protocol for defect closure should be employed to assure adequate statistical power.

Supplementary Materials:
The following supporting information can be downloaded at https: //zenodo.org/records/10069764(accessed on 25 December 2023).Video: Thoracoscopic CDH repair using a barbed suture.Informed Consent Statement: Informed consent was obtained from all families involved in the study.

Data Availability Statement:
The data presented in this study are available on request from the corresponding author.The data are not publicly available due to privacy and data protection issues of our institution.

Figure 1 .
Figure 1.Sutures used in this study.The V-Loc TM (Medtronic GmbH, Meerbusch, Germ (a) has small spiral spikes that prevent backslipping of the suture, while the Quill TM (C GmbH, Zurich, Switzerland), suture (b) features small spiral oblique cut-in leaflets th same manner (see magnified inlays).

Figure 1 .
Figure 1.Sutures used in this study.The V-Loc TM (Medtronic GmbH, Meerbusch, Germany) suture (a) has small spiral spikes that prevent backslipping of the suture, while the Quill TM (Corza Medical GmbH, Zurich, Switzerland), suture (b) features small spiral oblique cut-in leaflets that act in the same manner (see magnified inlays).

Figure 2 .
Figure 2. Thoracoscopic closure of a type C defect (a) using a barbed suture (b).

Figure 2 .
Figure 2. Thoracoscopic closure of a type C defect (a) using a barbed suture (b).

Figure 3 .
Figure 3. Left-sided CDH with stomach-up (SU) configuration and mediastinal shift to right (a).After barbed suture open repair via laparotomy, the left diaphragm shows a contour.Severe pulmonary hypoplasia (PH) is evident (b).

Figure 3 .
Figure 3. Left-sided CDH with stomach-up (SU) configuration and mediastinal shift toward the right (a).After barbed suture open repair via laparotomy, the left diaphragm shows a flat, even contour.Severe pulmonary hypoplasia (PH) is evident (b).

Figure 4 .
Figure 4. Box plot of operative time in the barbed suture group (left, green) compared to controls (right, red).Although the Mann-Whitney U-test showed no statistical difference (p = 0.24), this lack of significance was mainly driven by 2 severe outliers in the barbed suture group (patients 6 and 8)which had large defects that required a complex patch repair.After eliminating the 2 outliers from the calculation, a trend toward shorter operative times in the barbed suture group was evident (p = 0.06).

Figure 4 .
Figure 4. Box plot of operative time in the barbed suture group (left, green) compared to controls (right, red).Although the Mann-Whitney U-test showed no statistical difference (p = 0.24), this lack of significance was mainly driven by 2 severe outliers in the barbed suture group (patients 6 and 8)which had large defects that required a complex patch repair.After eliminating the 2 outliers from the calculation, a trend toward shorter operative times in the barbed suture group was evident (p = 0.06).

Author Contributions:
Conceptualization, O.J.M. and E.W.; methodology, O.J.M., E.W., A.-S.H. and C.Z.; validation, N.R.M. and O.J.M.; formal analysis, N.R.M. and O.J.M.; investigation, N.R.M., B.H. and E.W.; resources, O.J.M.; data curation, N.R.M. and O.J.M.; writing-original draft preparation, N.R.M.; writing-review and editing, O.J.M. and B.H.; supervision, O.J.M.; project administration, O.J.M.All authors have read and agreed to the published version of the manuscript.Funding: This research received no external funding.Institutional Review Board Statement: The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the LMU Medical Center (protocol code 23-0881 and date of approval: 12 December 2023).

Table 1 .
Demographic information, intraoperative findings, postoperative results, complications, and outcomes of patients who underwent congenital diaphragmatic hernia repair using barbed sutures at our institution.The lower 2 rows show descriptive statistics of the variables, shaded in grey.