COMPARATIVE STUDY BETWEEN VACUUM ASSISTED OPEN EXCISIONS VERSUS OPEN ALONE IN TREATMENT OF COMPLICATED PILONIDAL SINUS

Document Type : Original Article

Authors

Department of General Surgery, Faculty of Medicine, Al-Azhar University (Cairo)

Abstract

Background: Pilonidal disease is a type of skin infection which typically occurs as a cyst between the cheeks of the buttocks and often at the upper end. Sacrococcygeal pilonidal sinus is a common disorder among young adults, observed most commonly in people aged 15-30 years with a 3:1 male-to-female ratio.
Objective: To evaluate the role of vacuum therapy in pilonidal sinus disease compared with standard open wound care after surgical excision.
Patients and Methods: This was a prospective study conducted on 50 patients who were candidates for surgical excision of pilonidal sinus at Al-Azhar University Hospitals during the period from January 2019 to December 2019. Patients were classified into two equal groups: Group A were subjected to the conventional open surgical method without suturing of the wound, and Group 2were subjected to closed surgical excision with putting a vaccum system.
Results: Our results revealed a significant elongation in the operative time in vacuum group than in open ordinary method. In our study, the infection of the wound was more common in group A "ordinary open method" than the vacuum group "group B". Also, the recurrence rate after three months of follow up of cases was more common in group A than in group B. The time needed for complete healing in group B was shorter than in group A. Our study showed a significant decrease in frequency of dressing, and a significant patient satisfaction as well as early regain of normal daily activity in group B than in group A.
Conclusion: The use of vacuum assisted closure (VAC) therapy in cases of pilonidal disease has its advantageous effect in decreasing complications and accelerating healing.

Keywords


COMPARATIVE STUDY BETWEEN VACUUM ASSISTED OPEN EXCISIONS VERSUS OPEN ALONE IN TREATMENT OF COMPLICATED PILONIDAL SINUS

By

Yousef Ahmed Yousef El-Tohfa, Essam El-Deen Abd El-Azeem Zayed and Abd El-Fattah Morsi Saeid Mohammed

Department of General Surgery, Faculty of Medicine, Al-Azhar University (Cairo)

Corresponding author: Yousef Ahmed Yousef El-Tohfa,

Mobile: (+20) 1010607579, E-mail: y_ahmed201010@yahoo.com

ABSTRACT

Background: Pilonidal disease is a type of skin infection which typically occurs as a cyst between the cheeks of the buttocks and often at the upper end. Sacrococcygeal pilonidal sinus is a common disorder among young adults, observed most commonly in people aged 15-30 years with a 3:1 male-to-female ratio.

Objective: To evaluate the role of vacuum therapy in pilonidal sinus disease compared with standard open wound care after surgical excision.

Patients and Methods: This was a prospective study conducted on 50 patients who were candidates for surgical excision of pilonidal sinus at Al-Azhar University Hospitals during the period from January 2019 to December 2019. Patients were classified into two equal groups: Group A were subjected to the conventional open surgical method without suturing of the wound, and Group 2were subjected to closed surgical excision with putting a vaccum system.

Results: Our results revealed a significant elongation in the operative time in vacuum group than in open ordinary method. In our study, the infection of the wound was more common in group A "ordinary open method" than the vacuum group "group B". Also, the recurrence rate after three months of follow up of cases was more common in group A than in group B. The time needed for complete healing in group B was shorter than in group A. Our study showed a significant decrease in frequency of dressing, and a significant patient satisfaction as well as early regain of normal daily activity in group B than in group A.

Conclusion: The use of vacuum assisted closure (VAC) therapy in cases of pilonidal disease has its advantageous effect in decreasing complications and accelerating healing.

Keywords: Pilonidal Sinus; VAC; NPWT.

 

 

INTRODUCTION

     Pilonidal disease is an inflammatory and infectious soft tissue disorder of the sacrococcygeal intergluteal region. Wide complete excision of the abnormal tissue remains the dominant treatment, although controversy exists with respect to the preferred extent of excision, techniques and preferences for attempted primary closure, and management of open wounds following excision (Sasse et al., 2013). Symptoms may include pain, swelling, and redness. There may also be drainage of fluid, but rarely a fever (Khanna and Rombeau, 2011). Some people with a pilonidal cyst are asymptomatic (Lim and Shabbir, 2019). If there is infection, treatment is generally by incision and drainage just off the midline. Shaving the area may prevent recurrence. More extensive surgery may be required if the disease recurs. Antibiotics are usually not needed. Without treatment the condition may remain long term (Mubashir, 2018).

     A significant fraction of pilonidal disease results in an open wound after wide excision, and different strategies have evolved over time to facilitate healing of complex open pilonidal wounds. Most commonly, the open wound is packed with gauze on a daily or twice daily basis over a long period of time. The wound gradually heals in this manner by secondary intention, and the process can often take 6 months. Case reports have described a time course of up to 2 years for healing of open pilonidal wounds (Bianchi et al., 2018). Additional strategies have included flap surgery, delayed primary closure and the use of vacuum-assisted wound healing devices. Each of these approaches involves a level of patient discomfort, cumbersomeness, and a long period of time to complete healing (Tas et al., 2017).

     Negative pressure wound therapy (NPWT) is one of the treatment approaches to increase healthy granulation tissue for complex wounds (Ozkan et al., 2016). It is also known that NPWT is an effective therapy decreasing bacterial contamination in wounds. There are few reports about its successful use in the management of pilonidal sinus disease and recurrent form in addition to surgical treatment (Doll et al., 2016).

     The aim of this study was to evaluate the role of vacuum therapy in pilonidal sinus disease compared with standard open wound care after surgical excision.

PATIENTS AND METHODS

     A prospective outcome analysis was done for 50 patients who were candidates for surgical excision of pilonidal sinus at Al-Azhar University Hospitals during the period from January 2019 to December 2019. Patients with pilonidal sinus: primary and recurrent. Inclusion criteria Primary or recurrent pilonidal sinus: infected or not infected. Exclusion criteria: Pilonidal sinus associated with peri-anal fistula.

     Patients were classified into two randomized equal groups: Group I: Patients were subjected to the conventional open surgical method without suturing of the wound, and Group II: Patients were subjected to closed surgical excision with putting a vacuum system. Informed consents were taken from all patients of the study after informing them about the surgical procedure and its nature, duration, and possible complications.

     All patients of the study were subjected to:

I.          Preoperative Assessment:

a.  Clinical assessment: Complete history taking. Medical history: focusing on the presence of other co-morbidities which may affect the process of wound healing. Present history: Onset, course, and durations of the present condition, previous surgeries and its complications which may or may not result in such condition. Clinical examination.

b.  Investigations: Routine investigations for preoperative preparation. Specific investigations for recurrent cases that may include MRI, fistulogram or sinogram.

II.        Surgical procedure:

a.  Anesthesia: All patients received a general or local spinal anesthesia.

b.  Position: Patients were positioned in left lateral or the prone position.

c.  Surgical technique involved delineation of the sinus tracts with blue ink instillation through the primary sinuses. Complete surgical incision of the pilonidal sinus complex (the combination of primary sinuses, associated infected cavity, tracts, and/or secondary sinuses), then excising outside the blue ink-stained tissue with diathermy. Long-acting local anesthetic may be infiltrated.

III. Postsurgical Care: Group 1: Change the dressing daily using Iruxol ointment and silver nitrate ointment. Group 2: The wound cavity was filled with black foam dressing and an air-tight adhesive dressing was applied and connected to a unit providing continuous negative pressure of 125 mmHg to avoid skin irritation.

NPWT machine used: We used 3 devices. The machine was formed of 2 main components (i) Suction machine: It was low flow low suction machine with adjustable pressure and barometer to adjust the pressure needed for the dressing. (ii) Electrical timer: It was connected to the power supply of the suction machine to adjust the switch on and off of the VAC. The machine had been adjusted to be switched on for 5 minutes and switched off for 3 minutes. Continuous suction machine without using of the timer was used in case of dressings sealed with difficulty due to presence of site of leakage or large wounds with heavy exudate.

The dressing: (i) The sponge: Sponge selection was based on many factors, e.g. appropriate bore size, sponge intensity, and sponge thickness. So, 2 types were selected: the 1st type with thickness of 4 cm which we used for deep wounds and wounds with heavy exudate, while the 2nd type with thickness of 2 cm was used for all other wounds. (ii) The incifilm. (iii) The connecting tube: Ryle can be used as suction tube either within the sponge or over the sponge, and then connected to the suction machine.

Dressing application: (i) Cutting the foam dressing to dimensions that allowed the foam to be placed gently into the wound without overlapping onto intact skin. Cutting the foam was done away from the wound to prevent small pieces to fall into or be left in the wound upon dressing removal. (ii) Cutting the sheet or the incifilm to cover the foam dressing, and an additional 3-5 cm border of intact with the surrounding skin. Sometimes, we cut the sheet into multiple small pieces for easier handling, if a leak source was identified, patch with additional piece to ensure complete sealing. We used excess sheet to seal difficult areas, if needed. Patients of the study were followed up every 2 weeks for 3 months.

Statistical analysis:

     Results of the present study were statistically analyzed using SPSS 25 (IBM, USA). Data were represented as mean + standard deviation (SD) or number and percentage. Numerical data were compared using independent t-test while categorical data were compared using Fisher exact test or Chi-square test as appropriate. ROC curve was used to evaluate the performance of different tests differentiate between certain groups. The level of significance was taken at P value < 0.050.


 

RESULTS

 

 

     The age of group A patients ranged between 16-38 years with a mean age of 26.84 ± 5.4 years, while the age of group B patients ranged between 21-44 years with a mean age of 32.44 ± 6.8 years and the statistical analysis revealed a non-significant difference between both groups of the study (P = 0.074).Twenty-two patients in group A were males (22/25, 88%), and 3 of them were females (3/25, 12%) with a male to female ratio of 7.3:1, while in group B 23 patients (23/25, 92%) were males, and (2/25, 8%) were females with a male to female ratio of 11.5:1 and the statistical analysis revealed a male predominance in both groups (P = 0.01 and 0.01 respectively) with a non-significant difference between both groups regarding sex (P = 0.869 and 0.753 respectively (Table 1).


 

Table(1):    Age and Sex distribution in cases of the studied groups

Age

Group A

Group B

P

Range

Mean±S.D

16-38

26.84±5.4

21-44

32.44±6.8

0.074

Sex

Male

Female

P

No.

%

No.

%

Group A

Group B

22

23

88%

92%

3

2

12%

8%

0.01

P

0.869

0.753

 

 

 

     The operative time in group A ranged between 20-40 min with a mean time of 29.4±5.7 min while in group B patients it ranged between 30-50 min with a mean of 40.28±6.03 min and the statistical analysis revealed a significant increase in the operative time of group B than in group A of the study (P = 0.001) (Table 2).

 

 

Table (2):   Operative time in cases of the studied groups

Operative time

Group A (N=25)

Group B (N=25)

P

Range

Mean±S.D

20-40

29.4±5.7

30-50

40.28±6.03

0.001

 

 

     Three cases (3/25, 15%) of cases of group A had recurrence of the pilonidal disease after the surgical interference, while in group B patients only one case (1/25, 4%) had recurrence of pilonidal disease after surgical interference, and the statistical analysis revealed that there was a not significant increase in the percentage of recurrence in group A than in group B (P>0.05) (Table 3).

 

 

 

Table (3):   Post-operative recurrence in cases of the studied groups

Postoperative Recurrence

Yes

No

P

No.

%

No.

%

Group A

Group B

3

1

15%

4%

22

24

88%

96%

0.001

P

0.031

0.683

 

 

     The time needed for complete healing in group A patients ranged between 7-10 weeks with a mean period of 8.55±1.02 weeks, while in group B patients it ranged between 5-6 weeks with a mean period of 5.28±0.92 weeks and the statistical analysis revealed a significant reduction in the period needed for complete healing in group B than in group A (P = 0.001) (Table 4).

 

 

Table (4):   Time for complete healing in cases of the studied groups

Time for complete healing

Group A

Group B

P

Range

Mean±S.D

7-10

8.55±1.02

5-6

5.28±0.92

0.001

 

 

     Most of cases (19/25, 76%) of group A passed without infection, while only 6 cases (6/25, 24%) had post-operative infection, and in group B 21 cases (21/25, 84%) passed without infection, while only 4 cases (4/25, 16%) has post-operative infection, and the statistical analysis revealed that there was a not significant increase in the percentage of post-operative infection in group A than in group B (P > 0.05) (Table 5).

 

 

Table (5):   Distribution of post-operative infection in cases of the studied groups

Postoperative infection rate

Yes

No

P

No.

%

No.

%

Group A

Group B

6

4

24%

16%

19

21

76%

84%

0.001

P

0.021

0.683

 

 

     In group A, the frequency of dressing ranged between 29-38 times with a mean of 35.1±3.3 times, while in group B the frequency of dressing ranged between 15-18 times with a mean of 16.5±1.7 times, and the statistical analysis revealed a significant reduction in number of dressing times in group B than in group A (P = 0.001) (Table 6).

 

 

Table (6):   Frequency of dressing in cases of the studied groups

Frequency of dressing

Group A

Group B

P

Range

Mean±S.D

29-38

35.1±3.3

15-18

16.5±1.7

0.001

 

 

 

 

 

 

DISCUSSION

     In our study, there was no difference between both groups regarding age and gender, but there was a male predominance in each group. Banasiewicz et al. (2013) found that there was no difference between both groups regarding gender which was in agreement with our results, but all patients in both groups were males which disagreed with our results as the Egyptian males are almost hairy, while females are mostly house-wives.

     Our results revealed a significant elongation in the operative time in vacuum group than in open ordinary method. Banasiewicz et al. (2013) found that there was no difference between both groups regarding operative time which disagree with our results. This was because, in our group, the institution of the vacuum assisted closure (VAC) set took some time which increased the operative time in group B.

     In our study, the infection of the wound was more common in group A "ordinary open method" than the vacuum group "group B". Also, the recurrence rate after three months follow up of cases was more common in group A than in group B. Chmielecki et al. (2019) found that the use of NWPT postoperatively in cases of pilonidal disease decrease the complications rates than standard open surgical method which was in agreement with what we found in our study. Bianchi et al. (2018) found that the use of NPWT in pilonidal disease significantly decrease postoperatively complications as seroma and infections than the standard open surgical method which run in line with our results. Strugala and Martin (2017) found that the use of VAC therapy in pilonidal disease decrease the infective complications post-operatively than the standard open surgical method which runs in line with our results. López et al. (2020) found that open surgical procedure for pilonidal disease significantly complicated by infection of surgical site, and a recurrence rate of about 10% which was in agreement with our study.

     In our study, the time needed for complete healing in group B was shorter than in group A. Banasiewicz et al. (2013) found that the postoperative time needed for complete healing was shorter in VAC therapy which run in lines with our results. Biter et al. (2014) found that there was no difference between VAC group and standard open method regarding the time for complete healing which disagrees with our results but they found significant reduction in the wound size in the first two postoperative weeks which run in line with our results. Danne et al. (2017) concluded that the use of VAC- or NPWT-therapy is improving the healing process especially in the first two postoperative weeks and reduced recurrence rates are reported comparing the method to standard laying open procedures which run in lines with our study.

     Our study revealed that there was a significant decrease in frequency of dressing, a significant patient satisfaction as well as early regain of normal daily activity in group B than in group A. Banasiewicz et al. (2013) found that the use of VAC dressing leads to speed the granulation process in the wound and reducing the inflammation-related edema, results in resolution of pain, leading to improved functional comfort of patients and obviously facilitates restoration of complete activity which run in lines with our results. Hussain et al. (2018) found that patients who are given a portable NPWT device need to be visited up to every 48 hours by trained medical staff. This is mainly for dressing changes, but also to check that their device usage is appropriate that was in agreement with our results.

CONCLUSION

     The use of VAC therapy in cases of pilonidal disease has its advantageous effect in decreasing complications and accelerating healing.

Conflict of interest: The authors declare no conflict of interest.

Funding sources: The authors have no funding to report.

Acknowledgement: The authors are grateful for the patients without whom this study would not have been done.

REFERENCES

  1. Banasiewicz T, Bobkiewicz A, Wysocki MB, Biczysko M and Ratajczak A. (2013): Portable VAC Therapy Improve the Results of the Treatment of the Pilonidal Sinus--Randomized Prospective Study. Pol Przegl Chir., 85(7): 371-376.
  2. Bianchi E, Lei J, Adegboyega T, Shih SS and Berrones M. (2018): Negative pressure wound therapy is beneficial in the treatment of pilonidal disease. Journal of the American College of Surgeons, 227(4): 109-110.
  3. Biter L, Beck GM, Mannaerts GH, Stok M and van der Ham A. (2014): The Use of Negative-Pressure Wound Therapy in Pilonidal Sinus Disease: A Randomized Controlled Trial Comparing Negative-Pressure Wound Therapy Versus Standard Open Wound Care After Surgical Excision. Dis Colon Rect., 57(12): 406-1411.
  4. Chmielecki J, Ferenc J and Banasiewicz T. (2019): The role of negative pressure wound therapy in the treatment of pilonidal disease. Neg Pres Wound Ther J., 6(1): 14-17.
  5. Danne J, Gwini S, McKenzie D and Danne P. (2017): A retrospective study of pilonidal sinus healing by secondary intention using negative pressure wound therapy versus alginate or gauze dressings. Ostomy Wound Manag., 63(6): 47-53.
  6. Doll D, Luedi MM and Wysocki AP. (2016): Pilonidal sinus disease guidelines: a minefield? Tech Coloproctol., 20: 263-264.
  7. Hussain F, Bramham B, Parveen S and Chakaravarty B. (2018): Pilonidal sinus: Surgical outcome of lay open versus primary closure technique. IOSR J Dent Med Sci., 17(2): 01-07.
  8. Khanna A and Rombeau JL. (2011): Pilonidal disease. Clin Colon Rectal Surg., 24(1): 46-53.
  9. Lim J and Shabbir J (2019): Pilonidal Sinus Disease - A Literature Review. World Journal of Surgery and Surgical Research - General Surgery, 2: 1-6.
  10. López JJ, Cooper JN, Halleran DR, Deans KJ and Minneci PC. (2020): High Rate of Major Morbidity after Surgical Excision for Pilonidal Disease. Surg Infect., 19(6): 603-607.
  11. Mubashir M (2018): Evaluation of Patients of Pilonidal Disease in Surgical Ward of Tertiary Care Unit: A Hospital Based Study. Int J Med Res Prof., 4(4): 280-83.
  12. Ozkan OF, Koksal N, Altinli E, Celik A and Uzun MA. (2016): Fournier’s gangrene current approaches. Int Wound J., 13: 713-6.
  13. Sasse KC, Brandt J, Lim DC and Ackerman E. (2013): Accelerated healing of complex open pilonidal wounds using MatriStem extracellular matrix xeno-graft: nine cases. J Surg Case Report, 4: 3-5.
  14. Strugala V and Martin R. (2017): Meta-analysis of comparative trials evaluating a prophylactic single-use negative pressure wound therapy system for the prevention of surgical site complications. Surgical Infections, 18(7): 810-819.
  15. Tas S, Ozkan OF, Ocakli MM, Arslan E and Kiraz A. (2017): Management of flap dehiscence after Limberg procedure for recurrent pilonidal disease by negative pressure wound therapy (NPWT). ABCD Arq Bras Cir Dig., 30(1):71-74.


دراسة مقارنة بین الاستئصال المفتوح بمساعدة الفراغ (الڤاک) والاستئصال المفتوح فقط فى علاج الناسور العصعصى المعقد

عصام الدین عبد العظیم زاید, عبد الفتاح مرسى سعید محمد, یوسف أحمد یوسف التحفة

قسم الجراحة العامة, کلیة الطب، جامعة الأزهر (القاهرة)

خلفیة البحث: یعد الناسور العصعصى نوعا من إلتهابات الجلد التى تحدث غالباً بین فلقتى المقعدة من الناحیة العلیا، ویحدث غالباً فى صغار البالغین مابین 15-30 عاماً. ویعالج الجرح الجراحى الناتج عن العلاج الجراحى إما بالالتآم الأولى أو الثانوى أو الإصلاح عن طریق تحویلات الجلد.

الهدف من البحث: تقییم دور الضغط السلبى "الشفط" فی علاج الناسور العصعصى مقارنة مع الطریقة التقلیدیة فی علاج الناسور العصعصى بعد الإستئصال الجراحى.

المرضی وطرق البحث: تمت هذه الدراسة على خمسین من المرضى الذین یعانون من الناسور العصعصى فی مستشفیات جامعة الأزهر فی الفترة مابین ینایر 2019م إلى دیسمبر 2019م. تم تقسیم المرضى إلى مجموعتین الأولى تم لها استئصال الناسور العصعصى بالطریقة التقلیدیة مع الغیارات التقلیدیة بعد الجراحة حتى التآم الجرح، بینما المجموعة الثانیة تم لها استئصال الناسور جراحیاً مع وضع جهاز لشفط الإفرازات من مکان الجراحة حتى یتم تکوین النسیج النامى وبعدها یتم للمرضى الغیارات التقلیدیة.

نتائج البحث: أظهر البحث عدم وجود فارق إحصائى بین المجموعتین بمقارنة العمر والجنس، بینما وجد الذکور أکثر إصابة فی المجموعتین. کما أظهر البحث زیادة فى مدة العملیة الجراحیة فی المجموعة الثانیة، و فى معدل الإلتهابات الجراحیة بعد العملیة، وکذلک زیادة معدل الإرتجاع الجراحى فى المجموعة الأولى عنها فی المجموعة الثانیة. کذلک أظهر البحث نقص فی المدة المطلوبة لإکتمال إلتآم الجرح بعد الجراحة مع تقلیل معدل الغیارات الجراحیة وزیادة فی تقبل المرضى للطریقة العلاجیة، إضافة إلى سرعة عودة المرضى للنشاط العادى بعد الجراحة فی المجموعة الثانیة عنها فی المجموعة الأولى.

الإستنتاج: إستخدام الضغط السلبى "الشفط" بعد الجراحة فی حالات الناسور العصعصى یحمل الفائدة فى تقلیل المضاعفات وتسریع الإلتآم للجرح الجراحى، لهذا فإننا نوصى باستخدام هذه الطریقة کطریقة ممیزة فى العلاج الجراحى لهذه الحالات لتقلیل المضاعفات والإسراع فى إلتآم الجرح الجراحى.

  1. REFERENCES

    1. Banasiewicz T, Bobkiewicz A, Wysocki MB, Biczysko M and Ratajczak A. (2013): Portable VAC Therapy Improve the Results of the Treatment of the Pilonidal Sinus--Randomized Prospective Study. Pol Przegl Chir., 85(7): 371-376.
    2. Bianchi E, Lei J, Adegboyega T, Shih SS and Berrones M. (2018): Negative pressure wound therapy is beneficial in the treatment of pilonidal disease. Journal of the American College of Surgeons, 227(4): 109-110.
    3. Biter L, Beck GM, Mannaerts GH, Stok M and van der Ham A. (2014): The Use of Negative-Pressure Wound Therapy in Pilonidal Sinus Disease: A Randomized Controlled Trial Comparing Negative-Pressure Wound Therapy Versus Standard Open Wound Care After Surgical Excision. Dis Colon Rect., 57(12): 406-1411.
    4. Chmielecki J, Ferenc J and Banasiewicz T. (2019): The role of negative pressure wound therapy in the treatment of pilonidal disease. Neg Pres Wound Ther J., 6(1): 14-17.
    5. Danne J, Gwini S, McKenzie D and Danne P. (2017): A retrospective study of pilonidal sinus healing by secondary intention using negative pressure wound therapy versus alginate or gauze dressings. Ostomy Wound Manag., 63(6): 47-53.
    6. Doll D, Luedi MM and Wysocki AP. (2016): Pilonidal sinus disease guidelines: a minefield? Tech Coloproctol., 20: 263-264.
    7. Hussain F, Bramham B, Parveen S and Chakaravarty B. (2018): Pilonidal sinus: Surgical outcome of lay open versus primary closure technique. IOSR J Dent Med Sci., 17(2): 01-07.
    8. Khanna A and Rombeau JL. (2011): Pilonidal disease. Clin Colon Rectal Surg., 24(1): 46-53.
    9. Lim J and Shabbir J (2019): Pilonidal Sinus Disease - A Literature Review. World Journal of Surgery and Surgical Research - General Surgery, 2: 1-6.
    10. López JJ, Cooper JN, Halleran DR, Deans KJ and Minneci PC. (2020): High Rate of Major Morbidity after Surgical Excision for Pilonidal Disease. Surg Infect., 19(6): 603-607.
    11. Mubashir M (2018): Evaluation of Patients of Pilonidal Disease in Surgical Ward of Tertiary Care Unit: A Hospital Based Study. Int J Med Res Prof., 4(4): 280-83.
    12. Ozkan OF, Koksal N, Altinli E, Celik A and Uzun MA. (2016): Fournier’s gangrene current approaches. Int Wound J., 13: 713-6.
    13. Sasse KC, Brandt J, Lim DC and Ackerman E. (2013): Accelerated healing of complex open pilonidal wounds using MatriStem extracellular matrix xeno-graft: nine cases. J Surg Case Report, 4: 3-5.
    14. Strugala V and Martin R. (2017): Meta-analysis of comparative trials evaluating a prophylactic single-use negative pressure wound therapy system for the prevention of surgical site complications. Surgical Infections, 18(7): 810-819.
    15. Tas S, Ozkan OF, Ocakli MM, Arslan E and Kiraz A. (2017): Management of flap dehiscence after Limberg procedure for recurrent pilonidal disease by negative pressure wound therapy (NPWT). ABCD Arq Bras Cir Dig., 30(1):71-74.