• Users Online: 160
  • Print this page
  • Email this page


 
 
Table of Contents
ORIGINAL ARTICLE
Year : 2018  |  Volume : 1  |  Issue : 2  |  Page : 60-65

Retrospective single-center experience with the transversus abdominis muscle release procedure in complex abdominal wall reconstruction


Department of Hernia and Abdominal Wall Surgery, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China

Date of Submission15-Jun-2018
Date of Acceptance24-Jul-2018
Date of Web Publication16-Aug-2018

Correspondence Address:
Dr. Ping Wang
261 Huansha Road, Shangcheng, Hangzhou 310006, Zhejiang Province
China
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijawhs.ijawhs_11_18

Get Permissions

  Abstract 


OBJECTIVE: The objective of the study was to investigate the clinical utility of the transversus abdominis muscle release (TAR) procedure in complex abdominal wall reconstruction.
MATERIALS AND METHODS: Retrospective study of 32 patients with complex abdominal wall defects admitted to Hangzhou First People's Hospital between January 2016 and December 2017. Clinical materials were collected and analyzed.
RESULTS: Among 32 cases of large incisional hernias, there were 19 males (59.4%) and 13 females (40.6%). Mean age was 64.41 ± 12.11 years, body mass index was 30.00 ± 5.97 kg/m2, and mean width of the abdominal defect was 11.34 ± 1.82 cm. Twenty-four cases were midline incisional hernias with one case of planned incisional hernia after severe pancreatitis, and three cases were lateral. Five cases were recurrent incisional hernias. All patients underwent retromuscular mesh repair, with abdominal wall reconstruction using the TAR procedure. The operative time was 151.59 ± 28.64 min, and estimated blood loss was 118.12 ± 83.41 cm3. Length of hospital stay was 13.66 ± 2.72 days. Two cases had a superficial surgical site infection, five had Type II seroma, and one had intestinal obstruction. All postoperative complications resolved with nonsurgical therapy. No mesh infection, fistula, recurrence, or postoperative bulging was reported during follow-up.
CONCLUSION: Posterior component separation through TAR is a reliable and effective technique for complex abdominal wall reconstruction. Long-term follow-up is needed to assess potential recurrence.

Keywords: Abdominal wall reconstruction, incisional hernia, posterior component separation, transversus abdominis muscle release


How to cite this article:
Huang Y, Wang P, Ye J, Gao G, Zhang F, Wu H. Retrospective single-center experience with the transversus abdominis muscle release procedure in complex abdominal wall reconstruction. Int J Abdom Wall Hernia Surg 2018;1:60-5

How to cite this URL:
Huang Y, Wang P, Ye J, Gao G, Zhang F, Wu H. Retrospective single-center experience with the transversus abdominis muscle release procedure in complex abdominal wall reconstruction. Int J Abdom Wall Hernia Surg [serial online] 2018 [cited 2021 Apr 18];1:60-5. Available from: http://www.herniasurgeryjournal.org/text.asp?2018/1/2/60/239128




  Introduction Top


Incisional hernias are common complications after abdominal surgery with an incidence of about 11%–23%.[1],[2] Complex abdominal wall reconstruction is often mandatory during repair of large incisional hernias. Despite the rapid development of mesh repair and anterior component separation technique (ACST), recurrence after complex abdominal wall reconstruction is still as high as 10%–22%.[3] Complex abdominal wall reconstruction remains a major challenge for surgeons. Therefore, Novitsky et al. first reported a novel technique of posterior component separation (PCS) using transversus abdominis muscle release (TAR).[1] This article retrospectively reports our single-center experience with the TAR procedure in complex abdominal wall reconstruction.


  Materials and Methods Top


Thirty-two patients with large incisional hernias were admitted to Hangzhou First People's Hospital between January 2016 and December 2017. Preoperative abdominal computed tomography (CT) was performed to diagnose incisional hernia and evaluate defect width. Defect width larger than 10 cm was defined as a large incisional hernia according to the European Hernia Society classification of incisional abdominal wall hernia.[4] The indication for TAR operation was a large incisional hernia whose defect could not be closed under low tension. Of 32 patients, 24 had midline and three had lateral incisional hernias. Five had recurrent incisional hernias. Nineteen were males and 13 were females [Table 1]. All patients underwent TAR procedure with sublay mesh repair. The abdominal wall was reconstructed with the defect closed and the mesh overlap was more than 8 cm.
Table 1: Patient demographics and clinical characteristics

Click here to view


Perioperative data included operative time, blood loss, hospital stay, postoperative complications, and postoperative recurrence rate. Postoperative complications included surgical site occurrence (SSO),[5] intestinal obstruction, and intestinal fistula. SSO included incision dehiscence, hematoma, seroma, and surgical site infection (SSI). Type II and IV seroma with symptoms needing treatment was recorded.[6] According to the Centers for Disease Control wound class, SS is divided into superficial infection (skin or subcutaneous tissue) and deep infection (muscular layer or fascia layer).[7]

Clinical characteristics were collected. The statistical data were analyzed using IBM SPSS Statistics 22 (International Business Machines Corporation, Armonk, New York, America). Categorical variables were described using counts and percentages. Continuous variables were expressed as median and standard deviation (x– ± S). The study was approved by the Ethics Committee of our hospital, and all patients gave informed consent before surgery.

Surgical technique

The surgical technique of TAR in all patients was performed according to the steps introduced by Novitsky et al.[1],[8] After laparotomy and adhesiolysis through a skin incision at the hernia site, the defect edge was identified, and defect size was measured. The posterior rectus sheath was incised about 0.5–1 cm from the medial edge and the retromuscular plane was expanded toward the linea semilunaris. The neurovascular bundles perforating the rectus muscle were identified and preserved. The posterior rectus sheath was incised about 0.5 cm medial to the anterior/posterior rectus sheath junction to expose the transversus abdominis muscle. Then, the muscle was divided and the preperitoneal space was developed between transversus abdominis muscle and transversalis fascia/peritoneum. This space could be extended according to the size of mesh needed to be implanted as lateral as the psoas muscle. If necessary, the subxiphoid space and the space of Retzius were developed superiorly and inferiorly. After similar preparation was finished on both sides, the posterior rectus sheaths were reapproximated with a running absorbable coated suture. The mesh was placed in the retromuscular space and fixed with full-thickness transabdominal nonabsorbable monofilament sutures. Two closed suction drains were placed above the mesh. The anterior rectus sheaths then were reapproximated in the midline to restore the linea alba over the mesh using nonabsorbable monofilament sutures [Figure 1].
Figure 1: Surgical steps of transversus abdominis muscle release procedure. (a) Posterior rectus sheath incised 0.5–1 cm to the medial edge. (b) Retrorectus space developed and the neurovascular bundle identified. (c) Transversus abdominis released. (d) Posterior rectus sheath closed in midline. (e) Mesh implanted and drainage placed. (f) Anterior rectus sheath closed

Click here to view


Postoperative management and follow-up

Patients with a high risk of infection, such as those with diabetes, older age, and an immunosuppressed state, received prophylactic antibiotics for 12–24 h. Routine postoperative analgesia was given and early rehabilitation exercise was encouraged. A band was applied to reduce abdominal wall tension. The patients were advised to avoid sitting up directly from a supine position after surgery. Drains were removed 7–14 days postoperatively when the daily volume was <20 ml for 2 days. Ultrasound examination was used to rule out effusion in the retromuscular space before removing the drains.

Typical follow-up evaluation in the outpatient clinic consisted of a physical examination at 1, 3, 6, and 12 months and then annually after surgery. Abdominal CT was obtained routinely at 3 months and 1 year, and when patients had any abdominal discomfort. For patients who were not available in the outpatient clinic, follow-up was completed through telephone or other media with questionnaires. Abdominal CT was performed at local hospitals.


  Results Top


All 32 patients underwent complex abdominal wall reconstruction with TAR procedure. Nineteen (59.4%) of these patients were males and 13 (40.6%) were females, with an average age of 64.41 ± 12.11 years and median body mass index of 30.00 ± 5.97 (range, 23–39) kg/m2. The average width and length of the abdominal wall defect were 11.34 ± 1.82 cm and 18.59 ± 4.29 cm. The median defect size was 216.84 ± 76.99 cm2 (range: 110–390 cm2) [Table 1]. Twenty-four cases were midline incisional hernias, with one case of planned incisional hernia after severe pancreatitis, and three cases were lateral hernias. Five cases were recurrent incisional hernias. Concurrent disease included diabetes mellitus in 5 (15.6%) cases, chronic obstructive pulmonary disease in 4 (12.5%), aortic aneurysm in 1 (3.1%), and immunosuppression state in 3 (9.4%) cases. The median American Society of Anesthesiologists class was 2.51 ± 1.13. Based on the ventral hernia staging system reported by Petro et al. [Table 2],[9] 24 (75.0%) cases were Stage I ventral hernias and eight (25.0%) were Stage III. Twenty-nine cases underwent bilateral TAR, and three were unilateral. The median operative time was 151.59 ± 28.64 min, and the median intraoperative blood loss was 118.12 ± 83.41 cm3. The median size of mesh was 512.50 ± 103.95 cm2. The median length of hospital stay was 13.66 ± 2.72 days. The follow-up time was 6–29 months, with a mean follow-up time of 12.72 ± 5.06 months. There were two cases of superficial SSI, four of Type II and IV seroma, and one of incomplete mechanical intestinal obstruction after surgery. All resolved with nonsurgical treatment. No deep SSI, mesh infection, incision dehiscence, incision hematoma, intestinal fistula, pulmonary infection, deep vein thrombosis, or other complications were recorded. No recurrence or abdominal wall bulging was reported during follow-up.
Table 2: Cleveland clinic ventral hernia stages for surgical site occurrence and recurrence

Click here to view



  Discussion Top


Complex abdominal wall reconstruction surgeries are commonly mandatory in large incisional hernia repairs. These remain a major challenge for surgeons due to difficulty in closing large defects as well as high risk of complications and recurrence. Rives-Stoppa retromuscular sublay repair is a classic and effective technique for ventral hernia repair.[10],[11] However, it is difficult to close large defects and establish a larger space for mesh implantation with this technique. Ramirez et al. first reported ACST.[12] This technique not only reduces the difficulty in closing large defects but also increases the SSO rate. Some modifications of ACST have been made to reduce the SSO rate, including periumbilical perforator-sparing component separation. In spite of this, the SSO rate could still be as high as 26.3%–52%.[13],[14] Harth and Rosen and Rosen et al. developed endoscopic component separation technique with a low SSO rate but less component advancement.[14],[15] To make up for the disadvantages of conventional retromuscular sublay repair and ACST in complex abdominal wall reconstruction, Novitsky et al. developed PCS/TAR technique, which is becoming popular due to its confirmed surgical outcomes.[1],[8],[16]

The safety and effectiveness of the TAR procedure have been proven by several clinical data reports. Novitsky et al. reported long-term outcomes of TAR procedure with a mean follow-up time of 31.5 months. The SSO rate was 18.7% and SS was 9.1%, with a recurrence rate as low as 3.7%.[16] Winder et al. reported 37 cases of incisional hernia that underwent TAR procedure, with only two cases of SSO that needed clinical intervention and four cases of intestinal obstruction. The recurrence rate was 2.7% after a mean follow-up time of 21 months.[17] In our study, the SSO rate was 24.0% and all SSO cases resolved without reoperation or readmission. No recurrence or bulging was recorded during follow-up. However, longer follow-up may be needed to confirm the outcomes.

TAR procedure has advantages as follows: (1) More component advancement to reduce the difficulty of closing large defects; (2) large skin flap is not needed and the SSO rate is lower; (3) neurovascular bundle is preserved and abdominal wall muscle function is restored; (4) mesh is placed in the retromuscular space to avoid contact with abdominal viscera, resulting in a lower rate of mesh-related complications; and (5) A large preperitoneal space is established for mesh placement, reducing mesh fixation and chronic postoperative pain. Compared with ACST, TAR has lower SSO and recurrence rates. de Vries Reilingh et al. reported 43 cases of ACST with high SSO rate (32.6%) and recurrence rate (33%).[18] Similar results were obtained by Girotto et al. in their study of 96 cases of ACST.[19] Krpata et al. reported that the TAR group had significantly lower SSO rate (25.5% vs. 48.2%) and recurrence rate (3.6% vs. 14.3%) than the ACST group.[20] Mehrab et al. reported 174 cases of incisional hernias that underwent Rives-Stoppa repair with low SSO rate (3.4%) and recurrence rate (1.1%).[21] Wheeler et al. obtained similar results with Rives-Stoppa repair.[22] Thus, compared to the results from Novitsky et al. and our study with TAR, Rives-Stoppa repair has a relatively lower SSO rate and equivalent recurrence rate. The higher SSO rate with TAR may be attributed to the fact that more complex and large incisional hernias were selected for TAR procedures. In other words, more difficult cases underwent TAR but had an equivalent recurrence rate, indicating that TAR is safe and effective.

TAR technique is also an alternative for repair of complex abdominal wall hernias, such as those with “loss of abdominal wall domain,” recurrent ventral hernias, incisional hernias accompanied by a parastomal hernia, and others. In fact, TAR is in accord with Stoppa's principle of “giant prosthetic reinforcement of a visceral sac.”[23] The posterior rectus sheath is entered easily from the midline and can be extended from the xiphoid and costal margin cephalad to the pubis and Cooper's ligament caudally. The lateral extent of this dissection could be performed to expose lateral edges of both psoas muscles. This allows a very large sublay mesh placement necessary to achieve the adequate reinforcement of any defect during abdominal wall reconstruction. Paul et al. reported 29 cases of recurrent incisional hernias after ACST repair and three cases of parastomal hernias.[24] Petro et al. reported 11 cases of complex incisional hernias in kidney transplant recipients.[25] In our study, we successfully repaired three cases of large lateral incisional hernias, three cases of incisional hernias with a temporary stoma, and one case of large ventral hernia after the abdomen remained open due to severe pancreatitis. Thus, TAR technique can be applied to extremely challenging cases with success.

Although the precise degree of necessary mesh overlap remains unknown, guidelines for ventral hernia repair suggest that mesh extension of at least 5 cm beyond the hernia defect is paramount for a durable repair.[26],[27],[28] Novitsky et al. suggest that mesh should be placed lateral to the anterior axillary line for midline defects, inferiorly over Cooper's ligament for lower abdominal defects, and superiorly under the subxiphoid space for upper abdominal defects.[1],[8],[16] Mesh should be fixed with transabdominal and nonabsorbable monofilament. Fixation at Cooper's ligament inferiorly and the fascia along the xiphoid process superiorly is necessary to avoid recurrence. Less fixation is needed as long as there is enough mesh overlap. Our experience is that mesh should be fixed lateral to the edge of the released transversus abdominis. This ensures that mesh covers the potential defect created after TAR.

The key to the treatment of abdominal incisional hernia is the closure of abdominal wall defects and the recovery of abdominal wall function. TAR can significantly reduce the difficulty in closing the defect and the tension of the reconstructed abdominal wall. In addition, the vascular and nerve perforators of the rectus abdominis are retained during the operation. Preservation of the nerve can avoid atrophy of the abdominal muscles caused by denervation. The function of the abdominal muscles was preserved to the greatest extent, and the risk of a bulging abdominal wall was also reduced. Due to suture closure of the medial border of the anterior rectus sheath, the abdominal linea alba was reconstructed, and the abdominal wall was restored to physiological tension. Criss et al. used a dedicated dynamometer to perform isokinetic and isometric analysis of incisional hernia patients undergoing TAR surgery under different abdominal bending angles.[29] At the same time, the HerQles survey scale was used to evaluate the postoperative quality of life.[29] The results showed that the abdominal wall muscle strength and quality of life were improved significantly after the operation. It can be seen that TAR operation can achieve the purpose of functional reconstruction of the abdominal wall.

Open TAR operations commonly need relatively long skin incisions and division of large retromuscular spaces. The incidence of complications of SSO is still relatively high. With the development of the TAR technique and its associated instruments, laparoscopic TAR surgery has been gradually introduced and reported about in the literature. Belyansky et al. reported three cases of laparoscopic TAR, which had better outcomes of reduced SSO and hospital stay.[30] However, there are also disadvantages such as higher cost and longer operative time. At the same time, as in open TAR, there is also a long learning curve. For surgeons with experience in Rives-Stoppa repair, the learning curve of open TAR surgery requires five operations, and for those without experience requires 10–15 cases.[31] In other words, endoscopic TAR surgery requires an even longer learning curve. In addition, with the development of robotic surgery, many medical institutions have begun to perform robot-assisted ventral hernia repair and are trying to perform robot-assisted TAR surgery. Robot surgery shows remarkable advantages in closure of the posterior and anterior rectus abdominis sheath with less operative time. In the near future, laparoscopic TAR and robot-assisted TAR surgery technology may develop further and will gradually be popularized.


  Conclusion Top


Complex abdominal wall reconstruction for large incisional hernias remains a great challenge for surgeons. The use of transversus abdominis release has the advantages of lower operative incisional complications, lower incidence of mesh-related complications, and lower recurrence rate. At the same time, it is also an effective and safe method to achieve functional reconstruction of complex abdominal wall defects and has high clinical application value. Longer follow-up is needed to rule out potential recurrence in our study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Novitsky YW, Elliott HL, Orenstein SB, Rosen MJ. Transversus abdominis muscle release: A novel approach to posterior component separation during complex abdominal wall reconstruction. Am J Surg 2012;204:709-16.  Back to cited text no. 1
    
2.
Cassar K, Munro A. Surgical treatment of incisional hernia. Br J Surg 2002;89:534-45.  Back to cited text no. 2
    
3.
Paul EM, Rosen MJ. Open ventral hernia repair with component separation. Surg Clin North Am 2013;93:1111-33.  Back to cited text no. 3
    
4.
Muysoms FE, Miserez M, Berrevoet F, Campanell G, Champault GG, Chelala E, et al. Classification of primary and incisional abdominal wall hernias. Hernia 2009;13:407-14.  Back to cited text no. 4
    
5.
Ventral Hernia Working Group, Breuing K, Butler CE, Ferzoco S, Franz M, Hultman CS, et al. Incisional ventral hernias: Review of the literature and recommendations regarding the grading and technique of repair. Surgery 2010;148:544-58.  Back to cited text no. 5
    
6.
Morales-Conde S. A new classification for seroma after laparoscopic ventral hernia repair. Hernia 2012;16:261-7.  Back to cited text no. 6
    
7.
Horan TC, Gaynes RP, Martone WJ, Jarvis WR, Emor TG. CDC definitions of nosocomial surgical site infections, 1992: A modification of CDC definitions of surgical wound infections. Infect Control Hosp Epidemiol 1992;13:606-8.  Back to cited text no. 7
    
8.
Novitsky YW, editor. Posterior Component Separation Via Transversus Abdominis Muscle Release: The TAR Procedure. Hernia Surgery: Current Principles. 1st ed. Switzerland: Springer International Publishing; 2016. p. 117-35.  Back to cited text no. 8
    
9.
Petro CC, O'Rourke CP, Posielsk NM, Criss CN, Raigan S, Prabhu AS, et al. Designing a ventral hernia staging system. Hernia 2016;20:111-7.  Back to cited text no. 9
    
10.
Stoppa RE. The treatment of complicated groin and incisional hernias. World J Surg 1989;13:545-54.  Back to cited text no. 10
    
11.
Rives J, Pire JC, Flament JB, Palot JP, Body C. Treatment of large eventrations. New therapeutic indications apropos of 322 cases. Chirurgie 1985;111:215-25.  Back to cited text no. 11
    
12.
Ramirez OM, Ruas E, Dellon AL. “Components separation” method for closure of abdominal-wall defects: An anatomic and clinical study. Plast Reconstr Surg 1990;86:519-26.  Back to cited text no. 12
    
13.
Butler CE, Campbell KT. Minimally invasive component separation with inlay bioprosthetic mesh (MICSIB) for complex abdominal wall reconstruction. Plast Reconstr Surg 2011;128:698-709.  Back to cited text no. 13
    
14.
Harth KC, Rosen MJ. Endoscopic versus open component separation in complex abdominal wall reconstruction. Am J Surg 2010;199:342-6.  Back to cited text no. 14
    
15.
Rosen MJ, Williams C, Jin J, McGee MF, Schomisch S, Marks J, et al. Laparoscopic versus open-component separation: A comparative analysis in a porcine model. Am J Surg 2007;194:385-9.  Back to cited text no. 15
    
16.
Novitsky YW, Fayezizadeh M, Majumder A, Neupane R, Elliott HL, Orenstein SB, et al. Outcomes of posterior component separation with transversus abdominis muscle release and synthetic mesh sublay reinforcement. Ann Surg 2016;264:226-32.  Back to cited text no. 16
    
17.
Winder JS, Behar BJ, Juza RM, Potochny J, Paul EM. Transversus abdominis release for abdominal wall reconstruction: Early experience with a novel technique. J Am Coll Surg 2016;223:271-8.  Back to cited text no. 17
    
18.
de Vries Reilingh TS, van Goor H, Rosman C, Bemelmans MH, de Jong D, van Nieuwenhoven EJ, et al. “Components separation technique” for the repair of large abdominal wall hernias. J Am Coll Surg 2003;196:32-7.  Back to cited text no. 18
    
19.
Girotto JA, Chiaramonte M, Menon NG, Singh N, Silverman R, Tufaro AP, et al. Recalcitrant abdominal wall hernias: Long-term superiority of autologous tissue repair. Plast Reconstr Surg 2003;112:106-14.  Back to cited text no. 19
    
20.
Krpata DM, Blatnik JA, Novitsky YW, Rosen MJ. Posterior and open anterior components separations: A comparative analysis. Am J Surg 2012;203:318-22.  Back to cited text no. 20
    
21.
Mehrab M, Jangjoo A, Tavoos H, Kahrom M, Kahrom H. Long-term outcome of rives-stoppa technique in complex ventral incisional hernia repair. World J Surg 2010;34:1696-701.  Back to cited text no. 21
    
22.
Wheeler AA, Matz ST, Bachman SL, Thaler K, Miedema BW. Retrorectus polyester mesh repair for midline ventral hernias. Hernia 2009;13:597-603.  Back to cited text no. 22
    
23.
Stoppa R, Petit J, Abourachid H, Henry X, Duclaye C, Monchaux G, et al. Original procedure of groin hernia repair: Interposition without fixation of dacron tulle prosthesis by subperitoneal median approach. Chirurgie 1973;99:119-23.  Back to cited text no. 23
    
24.
Paul EM, Wang J, Petro CC, Juza RM, Novitsky YW, Rosen MJ, et al. Posterior component separation with transversus abdominis release successfully addresses recurrent ventral hernias following anterior component separation. Hernia 2015;19:285-91.  Back to cited text no. 24
    
25.
Petro CC, Orenstein SB, Criss CN, Sanchez EQ, Rosen MJ, Woodside KJ, et al. Transversus abdominis muscle release for repair of complex incisional hernias in kidney transplant recipients. Am J Surg 2015;210:334-9.  Back to cited text no. 25
    
26.
Silecchia G, Campanile FC, Sanchez L, Ceccarell G, Antinor A, Ansalon L, et al. Laparoscopic ventral/incisional hernia repair: Updated guidelines from the EAES and EHS endorsed consensus development conference. Surg Endosc 2015;29:2463-84.  Back to cited text no. 26
    
27.
Earle D, Roth JS, Saber A, Haggerty S, Bradley JF 3rd, Fanell R, et al. SAGES guidelines for laparoscopic ventral hernia repair. Surg Endosc 2016;30:3163-83.  Back to cited text no. 27
    
28.
Cuccurullo D, Piccol M, Agresta F, Magnone S, Corcione F, Stancanell V, et al. Laparoscopic ventral incisional hernia repair: Evidence-based guidelines of the first Italian consensus conference. Hernia 2013;17:557-66.  Back to cited text no. 28
    
29.
Criss CN, Petro CC, Krpata DM, Seafler CM, La N, Fiutem J, et al. Functional abdominal wall reconstruction improves core physiology and quality-of-life. Surgery 2014;156:176-82.  Back to cited text no. 29
    
30.
Belyansky I, Zahir HR, Park A. Laparoscopic transversus abdominis release, a novel minimally invasive approach to complex abdominal wall reconstruction. Surg Innov 2016;23:134-41.  Back to cited text no. 30
    
31.
Blatnik JA, Krpata DM, Novitsky YW. Transversus abdominis release as an alternative component separation technique for ventral hernia repair. JAMA Surg 2016;151:383-4.  Back to cited text no. 31
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
   Abstract
  Introduction
   Materials and Me...
  Results
  Discussion
  Conclusion
   References
   Article Figures
   Article Tables

 Article Access Statistics
    Viewed2859    
    Printed243    
    Emailed0    
    PDF Downloaded304    
    Comments [Add]    

Recommend this journal