The enhanced healing of a high‐risk, clean, sutured surgical incision by prophylactic negative pressure wound therapy as delivered by Prevena™ Customizable™: cosmetic and therapeutic results

Abstract

According to the literature, incisional closure complications may range from postoperative surgical site infections, representing 17–22% of health care‐associated infections, surgical wound dehiscence and formation of haematomas or seromas, and can lead to delayed or impaired incision healing. These kinds of situations are more common when wounds are closed under tension or in specific patient morbidities. Obesity, in particular, is associated with an impaired blood flow to tissues, predisposing the patient to increased risk of wound complications by various mechanisms. Incisional complications can become relevant economic burdens for health care systems because of an increase in the average length of hospital stay and readmissions, and additional medical and surgical procedures. Thus, a preventive therapy may have a critical role in the management of healing. Negative pressure wound therapy (NPWT) technology as delivered by Prevena™ Customizable™ (Kinetic Concepts Inc., San Antonio, TX) has recently been the focus of a new investigation, as a prophylactic measure to prevent complications via immediate postoperative application in high‐risk, clean, closed surgical incisions. The authors present a 62‐year‐old class II obese female, who underwent bilateral inguinal dermolipectomy. Prophylactic NPWT as delivered by Prevena™ was performed successfully over surgical incisions. Cosmetic and therapeutic results are shown.

Introduction

Historically surgeons have tried a variety of methods to promote healing after wound closure. Underlying patient comorbidities such as obesity, diabetes and poor vascular status, as well as risk factors such as smoking, radiation therapy, chemotherapy and the use of steroid or immunosuppressive drugs, present potential challenges in maintaining incision closure after an open surgical procedure 1, 2, 3. Also, surgical defects such as an excessive suture tension may adversely affect incisional healing. Incisional closure complications can include postoperative surgical site infection, accounting for 17–22 % of health care‐associated infections 4, 5, 6, surgical wound dehiscence 7, 8, 9, and formation of haematomas or seromas, and can lead to delayed or impaired healing of the incision. Traditionally, incisions have been closed by primary intention using sutures, staples, adhesive strips or a combination thereof. In patient groups at high risk for surgical site complications, the use of suture and staples induces stress concentrations and ischaemia where they engage the tissue, and elevated stress concentrations can cause ischaemia, fibrosis or other tissue injury 10.

These complications result in a decrease in patient quality of life, and are associated with the additional costs of rehospitalisation, reoperation, additional antibiotics, and home health services 11, 12.

Treatments used over clean, closed surgical incisions range from traditional gauze dressings 13 to more advanced therapies – advanced wound dressings such as hydrocolloids 13, growth factors 14, cultured skin 15 and negative pressure wound therapy (NPWT) 16, 17, 18.

NPWT technology, an established treatment for non‐healing wounds and open surgical incisions following infection or breakdown, has been the focus of recent investigation, in its use as delivered by Prevena™ Customizable™ (Incision Management System, Kinetic Concepts Inc., San Antonio, TX) as a prophylactic measure to prevent complications, via immediate postoperative application in high‐risk, clean, closed surgical incisions. Although the precise initiation criteria for incisional NPWT are yet to be defined, the therapy is primarily suited for patients with a clean, closed postoperative incision that is at high risk for infection and/or wound dehiscence.

Case presentation

A morbidly obese class II [160 cm tall, 95 kg; body mass index (BMI) = 37·1], 62‐year‐old female patient with treated hypertension reported a progressive weight increase from 65 to 134 kg after the birth of her third son. The patient was submitted to numerous endocrine controls, but no relevant functional data were detected; so the patient underwent several drastic diets and having lost 39 kg showed up with a clinical frame of upper leg lipodystrophy including skin flaccidity, adipose skin folds extending in the anterior‐medial and posterior region of the root of the thigh to the middle third of the thigh. Diffused venous patterns and signs of intertrigo were detected (Figure 1).

Figure 1.

A 62‐year‐old female patient before surgery.

The patient reported recurrent infections in skin folds and difficulty in walking because of a structural fatty tissue conformation and the skin deposits.

Surgery to remove the excessive dermoadipose tissue was planned under general anaesthesia. Standard systemic antibiotic prophylaxis therapy was administered with 2 g of cefazolin in association with prophylactic antithrombotic therapy with low‐molecular‐weight heparin (LMWH), 6000 UI the day before surgery.

Considering the status of both dermal and extensive adipose layers, we decided to perform a massive dermolipectomy by a ‘T’ incision. The incision was performed in the inguinal district and in the internal side of the thighs up to the proximal third and in the gluteal fold. The patient had a BMI of 37·1 and a 9 cm adipose layer.

After approximation of subcutaneous tissue, sutures were used in the different layers with a delayed absorbable monofilament suture 0, 2/0, 3/0 (Vicryl™ Ethicon^®, Johnson & Johnson International, Pomezia, Rome, Italy). Skin incisions were closed with staples. Drainage was positioned, one on the right side and one on the left side.

Closure needs up to nearly 2 hours, and there were significant concerns regarding wound dehiscence and infection.

Considering surgical issues such as incisions placement and extension, and the patient's clinical status, we classified the incisions as an increased risk for infection and dehiscence; therefore, we decided to place prophylactic NPWT as delivered by Prevena™ Customizable™ immediately after surgery (Figure 2) . The device was used over the surgical incisions and left in place, with no additional intervention or specialty care services, for up to 7 days with continuous negative pressure preset at −125 mmHg.

Figure 2.

Incisional negative pressure wound therapy (NPWT) device was placed on the closed incisions for 7 days.

After surgery, antibiotic therapy was continued: 1 g cefazolin twice per day for 10 days. Thromboprophylaxis of 6000 UI LMWH per day was continued for 10 days and antithrombotic stockings were advised. The patient was monitored daily for symptoms of wound infection.

The postoperative course has been uneventful: Prevena was removed on the seventh postoperative day and the surgical incisions looked clean and dry, showing no sign of infection. Neither pus nor serum had drained from the wound. There was <15 ml of wound drainage into the canister after 7 days of NPWT.

Figure 3 shows surgical incision aspects after 7 days of incisional NPWT.

Figure 3.

Clinical aspect of surgical incisions at first dressing change on postoperative day 7. There was <15 ml of wound drainage into the canister after 7 days of negative pressure wound therapy (NPWT).

A second Prevena was positioned and left in place for another 5 days. When the device was removed, the status of the incision was mature, with no dehiscence, no signs of infection and excellent healing status. The NPWT patient had no soft tissue wrinkles and the surgical incision had no signs of healing difficulty. No device‐related complications were observed (Figures 4 and 5).

Figure 4.

Clinical aspect of surgical incisions after removal of second dressing on postoperative day 12: no dehiscence, no signs of infection and good healing status.

Figure 5.

Healed incisions at 15 weeks follow‐up postoperatively.

Discussion

The evidence supporting the benefits of NPWT as an adjunctive therapy in healing management of difficult open wounds, has been well described in the literature 19, 20, 21, 22, 23, 24, 25, 26. A more recent NPWT technology for closed surgical incision management immediately after surgery (Prevena™ Customizable ™) has been developed. This new system incorporates all the functional elements of standard incisional NPWT, but in a simplified manner.

Prevena™ Customizable™, which has been cleared by the Food and Drug Administration and is commercially available, consists of a small, portable, single‐patient disposable therapy unit, preset to −125 mmHg negative pressure and a precut peel‐and‐place reticulated open‐cell foam dressing specifically designed for use over closed surgical incisions that are at high risk for postsurgical complications because of their placement and/or patient comorbidities.

There are no specific contraindications for Prevena™ Customizable™ with respect to standard NPWT except for sensitivity to silver, which is present in the interface layer to help control microbial growth in the layer.

A number of basic science and animal studies have determined that NPWT is associated with an increased angiogenesis and microvascular blood flow to the wound margins 27, 28, 29, 30, 31, 32, 33, 34. Furthermore, it has been demonstrated to reduce levels of haematoma/seroma35 by 63% not through removal of fluid into the canister but through an increased lymph clearance from the subcutaneous dead space and an enhanced macromorphological change of lymph structures, as suggested by Kilpadi 36, and in a significantly shorter time when compared with the controlled application of pressure dressing (average 1·6 versus 3·1 days, respectively; P = 0·03), as demonstrated by Stannard et al. 16. In addition, incisional NPWT seems to decrease the number of antibiotics used in the postoperative care by protecting from external contamination 37. Besides, a mechanism has been proposed that induces microdeformation at the wound surface and drawing of the surrounding skin together causing the release of growth factor, similar to the effect of tissue expansion 38. These are probably the major reasons for its beneficial effects in improving healing of clean, closed surgical incisions in addition to the beneficial effects of the NPWT therapy (stimulation of cell proliferation, reduction of inflammatory mediators, increasing arterial and subcutaneous oxygen partial pressure, reduction of the wound stress) already demonstrated over the last 18 years of clinical experience with this technology.

Our patient was a hypertensive morbidly obese (class II) female with a BMI of 37·1. Obesity is associated with diabetes, hypertension and vascular disorders that impair blood flow to tissue 39. The decreased vascularity of fat reduces wound oxygenation and concentration of prophylactic antibiotics in tissue 37. Increasing subcutaneous fat also predisposes a wound to greater tissue oedema and, ultimately, seroma formation. As a result of difficulty in obtaining adequate exposure to the surgical field, obese patients have to undergo longer surgical procedures and are at increased risk for tissue trauma. Finally, surgical incisions in obese patients are often under increased tension, further promoting breakdown 40.

According to Gomoll et al. 41, the reduced frequency of NPWT dressing changes (compared with other therapies) is particularly advantageous in the case of larger, obese patients and in difficult‐to‐access incision locations, and may also diminish the risk of incision contamination from 16% to 8%. Besides the decreased frequency of dressing changes, the reduction in contamination may be the result of a decreased risk of incision‐line dehiscence because of the increased appositional strength of the incision. A third possible reason for the decrease in infection rates may be the NPWT‐induced reduction in stress concentrations in tissue surrounding the insertion sites of sutures and staples, as suggested by the results of Wilkes et al. 10. It is known that excessive lateral tensions in and around the incision following surgery increase the likelihood of dehiscence, scarring as a result of the fibroblast‐to‐myofibroblast transition, poor cosmesis or a combination thereof 42. Furthermore, incisional edges retract when an incision or laceration is made in skin according to the direction of Langer's tension lines 43, 44, 45, 46 and this native skin tension opposes the closure of the incision. In certain circumstances, such as in the lower extremities, in obese patients or in locations where there is movement, this fact may result in excessive tension on sutures 1. These incisions are then at high risk for dehiscence. Therefore, incisional NPWT, thought to decrease myofibroblast number in the healing tissue, may potentially have a positive effect on cosmesis and functionality.

Wilkes et al. 10 showed, using a finite element model, that the negative pressure applied with this system decreased lateral tissue stresses and changed the direction of tissue stresses to a distribution that is typical for intact tissues. This modulation of the biomechanical environment around the incision site may facilitate enhanced apposition of the incision line and may be particularly beneficial for our morbidly obese patient, who has two bilateral incisions at sites over joints, where there are increased stresses as a result of motion/movement.

We left the device in place for a total of 12 days. Continuous high pressure, which optimises fluid removal, was selected in our practice because this device was applied on closed incisions rather than open wounds. No reports of pain or discomfort related to the NPWT at continuous high pressure were recorded. On the contrary, Prevena™ Customizable™ lowered patient anxiety and decreased the pain and discomfort of frequent dressing changes.

Conclusion

The evidence supporting the use of NPWT to improve healing in open wounds is widely published. However, its application on closed incisions is a relatively recent development and is not as well characterised.

We used Prevena™ Customizable™ in a 62‐year‐old female patient who was hypertensive and morbidly obese class II (BMI = 37·1) after she had undergone bilateral dermolipectomy in the groin area. Our patient had a higher baseline rate of wound complications and the two inguinal incisions were considered to be at high risk for dehiscence and infection as a result of a variety of reasons: obesity and hypertension associated with vascular disorders impair blood flow to tissue, reducing the concentration of effective antibiotics. Besides, the wide excision of underlying soft tissue down to the level of muscle fascia during the massive groin dermolipectomy had created dead space, allowing subdermal sero/haematoma formation, which was particularly pronounced because of the amount of subcutaneous fat, while the long surgical procedure had set an increased risk of tissue trauma. Moreover, surgical incisions were placed over an articulation and movement may have resulted in excessive tension on sutures, further promoting breakdown.

According to the literature, wound dehiscence and infection are expensive complications that often require additional surgery and long‐term intravenous antibiotic treatment 47, 48, 49.

We believe that on primarily clean closed surgical incisions, this device is safe and easy to use and functions like a splint, off‐loading midline tension on the skin incisions, thus diminishing resistance and tension on the wound overall. It also appears to wick early fluid and to maintain a more sterile wound environment than with conventional dressing, for the entire duration of the therapy. The reduced frequency of NPWT dressing changes (compared with other therapies) is particularly advantageous in the case of larger, obese patients and difficult‐to‐access incision locations and may also diminish the risk of incision contamination.

We believe that by pulling the incision edges together, Prevena™ Customizable™ is able to keep the incision isolated from the surrounding environment, and to reduce the formation of haematomas and seromas, thereby decreasing the rate of postoperative wound complications such as dehiscence and infections and thus assisting in achieving closure goals with potential cost savings.