|Year : 2019 | Volume
| Issue : 4 | Page : 1313-1317
Second-generation self-inflating tissue expanders: a new dimension in tissue expansion
Ibrahim A Soliman1, Tarek F Kishk2, Dalia M El Sakka2, Ashraf M Al Rahawy2
1 Department of Plastic Surgery, Prince Mohammad Bin Abdulaziz National Guard Hospital, Medina, KSA
2 Department of Plastic Surgery, Faculty of Medicine, Menoufyia University, Shibin Al Kawm, Al Minufiyah, Egypt
|Date of Submission||13-May-2019|
|Date of Decision||01-Jun-2019|
|Date of Acceptance||10-Jun-2019|
|Date of Web Publication||31-Dec-2019|
Ibrahim A Soliman
Source of Support: None, Conflict of Interest: None
To study the different uses of second-generation self-inflating tissue expanders regarding the advantages, disadvantages, and the rate of complications.
Tissue expansion is a valuable technique in soft-tissue reconstruction. Osmotic expanders are self-inflating and obviate the need for repeated injections. They eliminate port-site problems and reduce the potential to introduce infection. The use of such expanders has become more common in recent years.
Patients and methods
The study included two parts: retrospective part from January to June 2017 and prospective part from August 2017 till January 2019. The study included 40 patients, admitted to the Plastic Surgery at El-Menoufyia University Hospital and Prince Mohammad Bin Abdulaziz National Guard Hospital – Madinah in Saudi Arabia. The patients had post-burn scars, alopecia, and large nevi. A total of 69 second-generation self-inflating tissue expanders were implanted from January 2017 till January 2019, with a follow-up period of 12 months.
Of the patients, 30 patients were females and 10 were males. The indication was large scar in 30 cases, alopecia in five cases, and giant nevus in five cases. Extrusion occurred in 10 (14.4%) expanders, which occurred in six (15%) patients. The highest percentage of extrusion occurred in the scalp, in which six of 10 expanders extruded.
The study indicates that self-inflating expanders can be safely and effectively used for various plastic and reconstructive procedures especially in children. The fact that numerous painful and distressing filling sessions are obviated with these expanders is particularly beneficial for those children too young to understand and cooperate. Moreover, this approach minimizes the risk of infection and lowers costs.
Keywords: alopecia, hydrogel, osmed expanders, scars, self-inflating tissue expander
|How to cite this article:|
Soliman IA, Kishk TF, El Sakka DM, Al Rahawy AM. Second-generation self-inflating tissue expanders: a new dimension in tissue expansion. Menoufia Med J 2019;32:1313-7
|How to cite this URL:|
Soliman IA, Kishk TF, El Sakka DM, Al Rahawy AM. Second-generation self-inflating tissue expanders: a new dimension in tissue expansion. Menoufia Med J [serial online] 2019 [cited 2020 Apr 4];32:1313-7. Available from: http://www.mmj.eg.net/text.asp?2019/32/4/1313/274225
| Introduction|| |
The development of tissue expansion has added another technique to the armamentarium of the plastic surgeon for management of defects that cannot be closed primarily without undue tension . Tissue expansion provides donor skin that is optimal match in terms of skin color, texture, sensation and hair-bearing characteristics. Literature showed that the tissue expansion technique was used in almost all areas of the body from scalp to feet . First report of this method was in 1957, when Neumann used a rubber balloon to expand skin in the tempro-occipital area to reconstruct a traumatized ear . Twenty years later, the idea resurfaced by Radovan  and Argenta  who used a silicon inflatable expander in breast reconstruction. Since then, this technique has gained a lot of attention. Injectable (conventional) expanders were regularly used for this purpose. The expander needs to be filled manually through an external filling port. This leads to a couple of major disadvantages: the filling process is usually painful when the surgeon introduces the needle into the port underneath the skin, and the patient must come to a medical facility regularly in most cases, unless they are trusted with their expanders to be filled by them at their homes. In 1982, Austad and Rose  developed the first self-inflating tissue expander composed of hypertonic, saturated saline, which was abandoned. The reason was the increased risk of skin necrosis when the fluid leaked from its shell. In 1993, Weise  tested a newer hydrogel self-inflating expander on rats that gave a new horizon for tissue expansion. In 1999, Osmed (Ilmenau, Germany) introduced the self-inflating tissue expanders giving a new option for tissue expansion. The expanders are made from a solid material, such as hydrogel, vinyl pyrrolidone, or methyl methacrylate, that absorbs the surrounding tissue fluid and increase in size over a period of 6–8 weeks . The first-generation expanders rapidly increased in size and extruded outside the body. This caused pressure necrosis over the overlying skin flap. So they were modified by adding an envelope to decrease the unopposed expansion. The envelope is made of silicone and had pores to allow the fluid in; hence, those second-generation tissue expanders had a better outcome . The aim of this study was to evaluate the different uses of second-generation self-inflating tissue expanders regarding the advantages, disadvantages, and the rate of complications.
| Patients and Methods|| |
This study was conducted in Plastic and Reconstructive Surgery Department at El-Menoufyia University Hospital and Prince Mohammad Bin Abdulaziz National Guard Hospital – Madinah in Saudi Arabia. The study included 2 parts: part one was a retrospective study from January 2017 till July 2017 and part two was a prospective study from August 2017 till January 2019. It was approved by local ethical committee on July 2017. It included 40 (30 females and 10 males) patients with different indications: scars in 30 cases, alopecia in five cases, and large nevi in five cases. The age range was from 5 to 40 years. For all patients, second-generation self-inflating tissue expanders rectangular in shape were used [Figure 1].
|Figure 1: Osmed self-inflating expander – from left to right: unswollen, without silicone shell, swollen .|
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All the patients signed an informed consent for photography before and after surgery including publication for research issues.
All patients were subjected to the following
History taking, including the following:
- Patients' age, sex, occupation, and status of general health
- The exact cause of the skin defect.
Systemic examination was carried out to detect any associated medical condition.
- Site of the defect: scalp, face, trunk, or extremities
- Size of the defect
- Any signs of infection
- The condition and availability of the adjacent skin.
All patients underwent two-stage procedure
First stage (implantation of the expanders): this is done following measurements of the defect/lesion to be tackled and selection of the expander size/shape/volume. The normal skin next to the lesion to be removed is marked in a way to create a subcutaneous pocket in which the expander would be inserted. We used the company template for marking the pocket dimensions. The dimensions of the pocket should be equal to the final dimensions the expander is supposed to reach, as indicated on the company box. This was done in an attempt to make the expander get a bigger room to expand under and to decrease the unopposed pressure on the overlying skin to prevent ischemia and extrusion. In 25 cases of large lesion that required the insertion of more than one expander on one side, separate pockets were created to disallow any potential infection to spread from one expander to another.
The surgery started by making a 3–4-cm cut inside the lesion territory perpendicular to the expander's pocket. Dissection of the pocket was done leaving a 1-cm thick skin. A traumatic dissection of the pocket follows. The expanders were inserted, and the skin is closed in two layers.
Second stage (removal of the expander and flap advancement): the expander was ready for removal when it was deemed that the amount of expansion necessary to serve the purpose of covering the expected defect is completed. A period of ∼2 weeks is then given to allow the expanded skin to stay stretched to that level.
The incision for the advancement flap was at the border between the expander and the lesion/defect. This incision carefully deepened to the capsule. The expander is then gently removed. A trial advancement of the expanded flap across the lesion/defect was then made to assess the reach of the flap, and if the flap appears to fall marginally short or is a tight fit, an incision was carefully made with electrocautery to divide the base of the capsule. If any more release was necessary, then parallel incisions are carefully made in the capsule in the axis of advancement.
Once it was confirmed that the expander will cover the entire defect/lesion, excision of the lesion or final preparation of the defect is carried out and hemostasis confirmed. The flap was then advanced as required. A drain is inserted, which is usually removed after 1–2 days according to the output.
Closure is usually done in two layers: deep suturing with absorbable sutures (3–0 Vicryl) and skin closure with either subcuticular Monocryl or a running stitch of (3–0/4–0 ethilon, prolene). When extrusions occurred, the patients was admitted emergently.
Intravenous antibiotics were started at the time of admission, and the patients were taken to the operating room as soon as possible. A similar technique to electively remove the expander is used, but the pocket is thoroughly irrigated and cleaned. In case, the expander was inserted together with other expanders, the pocket would be inspected to make sure that the infection did not spread to another expander; drains were left in place like other elective cases. In all the cases, the infection did not spread, and the decision of removing the other expanders electively was made depending on whether the uninfected expander reached a reasonable volume or not.
For all of our patients, the following hospital data were obtained
- Operative details
- Operative time
- Operative complications. including wound infections, ischemia, skin necrosis, and extrusion
- Aesthetic outcome.
All data were collected, tabulated, and statistically analyzed The descriptive measures of central tendency (mean and median) and measures of dispersion (range, SD, minimum and maximum), besides frequency and the percentage were calculated by SPSS 20 statistical software package (SPSS Inc., Chicago, Illinois, USA).
| Results|| |
This study included 40 patients. Most of the patients (17/40) (42.5%) were in the age range 11–20 years. Most of the patients were females [30 (75%)] [Table 1]. The most common indication was scars in 30 (75%) cases, in which 50/69 expanders were implanted. Other indications included scalp alopecia in five (12.5%) cases, in which 9/69 expanders were implanted, and large nevi in five (12.5%) cases, in which 10/69 expanders were implanted.
The total number of expanders used is 69. All were second-generation self-inflating Osmed rectangular expanders. The most common site of expander insertion was trunk [29 (42%) expanders]. Most common size of expander used was 130 ml in 22 (31.8%) expanders. Final volume achieved was as follows: 47 (68%) expanders reached 100% of the predicted final volume, and 22 (32%) expanders reached average 62% of final predicted volume. The most common complication was extrusion with skin necrosis, which occurred in 10 expanders (14.4%) in six (15%) patients. The total number of complications occurred in 18 (26%) of 69 expanders [Table 2]. The aesthetic and functional outcome and patient satisfaction were excellent and good in 80% of the patients [Figure 2] and [Figure 3].
|Table 2: Analysis of postoperative complications as regards the site of implantation|
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|Figure 2: Case no. 2. A 16-year-old female with posttraumatic scar of the left thigh, during expansion period.|
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Of 69 expanders, 12 (17.3%) were found outside the silicone envelope with ruptured silicon envelope [Figure 4]: in eight (11.5%) expanders that was not complicated, the expander was outside the enclosing envelope, and in four (5.7%) expanders that were complicated, the expander was found in a similar state, which may have caused the extrusion in that patients. However, the envelope was intact in the other 12 complicated expanders.
|Figure 4: The expanders after removal found outside the silicone envelope with rupture of the envelope.|
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| Discussion|| |
Cutaneous expansion is used increasingly in reconstructive surgery for the treatment of a variety of problems in children and adults. The reconstruction of many congenital and acquired lesions has been made possible through the use of this technique . The first published clinical case of tissue expansion was by Neumann  who placed an inflated balloon subcutaneously to facilitate an ear reconstruction. No further development until 1976, when Radovan  reported using a silicone implant with self-sealing valve that could be placed entirely inside the body without external ports. Following Radovan's presentation, numerous clinical and experimental studies were published, leading to the wide acceptance and use of the technique . Researchers have looked for a self-inflatable device to overcome frequent hospital visits and repeat punctures to inflate expanders. In 1982, Austad and Rose developed the first self-inflating tissue expander composed of hypertonic, saturated saline, which was abandoned. The reason was the increased risk of skin necrosis when the fluid leaked from its shell . In 1993, Weise tested a newer hydrogel self-inflating expander on rats that gave a new horizon for tissue expansion . In 1999, Osmed (Ilmenau, Germany) introduced the self-inflating tissue expanders giving a new option for tissue expansion. The expanders are made from a solid material, such as hydrogel, vinyl pyrrolidone, and methyl methacrylate, that absorbs the surrounding tissue fluid and increase in size over a period of 6–8 weeks . The first-generation expanders rapidly increased in size and extruded outside the body. This caused pressure necrosis over the overlying skin flap. So they were modified by adding an envelope to decrease the unopposed expansion. The envelope is made of silicone and had pores to allow the fluid in hence those second-generation tissue expanders had a better outcome . After the introduction of the self-inflating tissue expanders, many reports were published about the use and versatility of these expanders, which included anophthalmia, breast reconstruction, free flap reconstruction, alopecia, giant nevi, and burn scars . The osmotic expander has many advantages: no injections are needed, thus, theoretically, lowering the possibility of infection, eliminating the associated pain, and significantly reducing the number of required visits to the outpatient clinic; the swelling is much more gradual and subtle, and there is no pain that usually follows the filling injection; the small initial volume of the expander requires a relatively small pocket, which is usually performed under local anesthesia and results in a relatively short scar . The main disadvantage is that the inflation process is uncontrollable . Rapid early uncontrolled expansion can lead to tissue ischemia or necrosis even with the second-generation expanders . Following insertion, expansion commences soon thereafter and cannot be delayed, for example, when there are concerns about primary wound healing. Additionally, once the expansion has begun, it cannot be interrupted, other than by removal of the device; this could present difficulties if any impending problems are noted with the wound or overlying skin viability . Overexpansion (a technique often employed with conventional expanders) is not possible. All these factors mean that the trade-off for a simpler procedure to insert the expander and the avoidance of multiple injections is reduced flexibility both during and at the end of the expansion process . Despite its versatility, tissue expansion has been associated with significant complications since its inception. In contrast to initial reports of complication rates of tissue expansion that were as high as 40%, recent series report overall complication rates in the range of 13–20% . Complication rate for the first-generation self-inflating tissue expanders was as high as 35% in some reports  until the second-generation exapander, which is enclosed by a silicone-fenestrated envelope, was introduced, after which the complication rate has decreased to some extent. Ronert et al.  reported a success rate of 93.3% for tubular breast management, 83.3% for other reconstructions, and 91% for all 26 second-generation expanders. However, Obdeijn et al.  reported a lesser success rate which was 70%; they had 20 expanders implanted, but in their experience, two of the six extrusions happened in radiated fields . Chummun et al.  reported overall complication rate of 30%. An impressive 96.2% success rate was reported in 2010 by Böttcher-Haberzeth et al.  in a study that was carried on pediatric population in which 53 expanders were implanted; the surgery was short and the expansion process was painless, because the patient did not have to get injections of fluid to fill the expander. No radiation was given to any of the patients, but this alone is not the cause of this greater success rate an oversized pocket potentially played an important factor in decreasing the extrusion rate . The results in our study are similar to those reported as the extrusion rate is 14.4%, and the overall complication rate is 26%. In this study, the aesthetic and functional outcome and patient satisfaction was excellent and good in 80% of the patients. This is similar to Böttcher-Haberzeth et al.  in their study, as they found 'excellent' and 'good' functional and cosmetic results in 86% of expanders.
| Conclusion|| |
Osmotic tissue expander is a useful addition in the armamentarium of the reconstructive plastic surgeon, especially when dealing with the pediatric population. We have been attracted to the use of osmotic expanders. An osmotically active system avoids the disadvantages of traditional silicone balloon expanders, such as pressure peaks following postoperative fillings, infections, and distant valve placement. It minimizes the patient's pain and discomfort during the swelling phase and eases the reconstruction process.
The OSMED expanders have many advantages compared with traditional expanders, but the indications for use should be considered very carefully. We feel that previous reports have been positive, and the limitations of this product must be acknowledged.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
The author would like to thank Dr. Osama Shareefi and Dr. Dr Samir awaad as they were the consultants that operated on the patients in Prince Mohammad Bin Abdulaziz National Guard Hospital – Madinah in Saudi Arabia and helped me to do this work.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]