Breast reconstruction with the latissimus dorsi BREAST

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1 BREAST Latissimus Dorsi Breast Reconstruction: How Much Nerve Resection Is Necessary to Prevent Postoperative Muscle Twitching? Klaus F. Schroegendorfer, M.D. Stefan Hacker, M.D. Stefanie Nickl, M.D. Martin Vierhapper, M.D. Jakob Nedomansky, M.D. Werner Haslik, M.D. Vienna, Austria Background: The latissimus dorsi muscle flap represents a valuable option in breast reconstruction but can result in postoperative twitching and retraction, discomfort, arm movement limitations, and breast deformation. These complications can be avoided by denervation of the thoracodorsal nerve; however, the optimal method of nerve management is unknown. This study presents the authors experience with the outcomes of latissimus dorsi flaps for breast reconstruction in the light of thoracodorsal nerve management strategies. Methods: The authors retrospectively collected data from 74 patients who underwent partial or total breast reconstruction with a latissimus dorsi flap alone or with an implant between January of 1999 and October of Follow-up data were collected at 12 and 24 months postoperatively. Results: In 56 patients (75.7 percent), the latissimus dorsi muscle was denervated at the time of surgery, whereas the thoracodorsal nerve remained intact in 18 patients (24.3 percent). No partial or total flap loss was observed. At 12 and 24 months follow-up, all patients with an intact thoracodorsal nerve showed twitching of the muscle, and 50 percent and 67.9 percent, respectively, of the denervated patients showed twitching (p < 0.001). No patient had twitching if more than 4 cm of nerve was excised at 12 or 24 months postoperatively, and the length of nerve resection was predictive of the presence of twitching. Conclusion: Denervation of the latissimus dorsi is a safe and reliable procedure that should be performed at the time of breast reconstruction and should include more than 4 cm to achieve a nontwitching breast with a stable volume and shape. (Plast. Reconstr. Surg. 134: 1125, 2014.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III. Breast reconstruction with the latissimus dorsi muscle still represents a valuable and important option in the treatment of the sequelae of surgical breast cancer treatment. Depending on the required volume for breast reconstruction, the flap can be used either as a myocutaneous flap alone or in combination with an implant. 1 3 Although perforator flaps have gained in popularity and are used preferably in autologous breast reconstruction operations, the latissimus dorsi flap is useful in patients for whom microsurgery is not feasible. 4,5 In this population, the latissimus dorsi flap procedure is a good alternative because of its relative simplicity and brief From the Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University Vienna. Received for publication February 27, 2014; accepted June 3, Copyright 2014 by the American Society of Plastic Surgeons DOI: /PRS duration and because the flap has a consistent vascular pattern and there is no need for a microvascular anastomosis. 2 Moreover, the latissimus dorsi flap is a viable option for a salvage procedure after a failed free flap. 6 In addition, it is a useful tool in partial breast reconstructions after a lumpectomy or partial mastectomy, in the correction of the chest deformity observed in Poland syndrome, or for the replacement of fibrotic or ulcerated tissue caused by radiation treatment or silicone oil injection Despite these advantages, this flap can cause distortion of the breast as a result of latissimus dorsi contraction, which has been noted by many surgeons Twitching of the transposed latissimus dorsi muscle because of persistent innervation has also been reported by several authors Disclosure: The authors have no financial interest to declare in relation to the content of this article

2 Plastic and Reconstructive Surgery December 2014 to cause discomfort and a sense of tightness. 14 Extending the upper arm can lead to superolateral contraction of the entire reconstruction. 14 Although the latissimus dorsi muscle can be denervated, to the best of our knowledge, the effectiveness of either division or resection of the thoracodorsal nerve has never been fully demonstrated. Many articles have been published regarding the anatomical architecture of the neural supply of the latissimus dorsi muscle, 17,18 but studies that deal with achieving sufficient denervation to prevent the above-mentioned complications are still lacking. The aim of this article was to examine our institutional experience with denervation of the latissimus dorsi muscle and detail the resulting clinical outcomes. PATIENTS AND METHODS After approval by the Medical University of Vienna Ethics Board (institutional review board 2068/2013) was gained, we retrospectively collected the following data from 74 patients who underwent surgery for either partial or total breast reconstruction with a latissimus dorsi flap alone or in combination with an implant between January of 1999 and October of The demographic data and type of reconstruction were recorded. Follow-up appointments were fixed at 12 and 24 months postoperatively, and patients were also examined beyond that period according to standard clinical procedures. Digital photographs were taken preoperatively, intraoperatively, and at 12 and 24 months postoperatively. The exclusion criteria were unclear or missing documentation of nerve length resection or missing follow-up. If implants were used, they were placed between the pectoralis muscle and the latissimus dorsi muscle; transection of the tendinous insertion at the humerus was performed in all patients. Denervation of the latissimus dorsi muscle was performed by means of either transection or resection of the thoracodorsal nerve. The manner of intraoperative nerve management was recorded and, in cases of resection, the length of the resected nerve was determined with a sterile ruler (Fig. 1). For assessment of postreconstruction twitching, the patient s upper arm was elevated 90 degrees in internal rotation, and the patient activated her latissimus dorsi muscle against resistance of the physician. 19 Twitching was recorded as present if there was any apparent movement of the breast with visible muscular contraction of the latissimus dorsi muscle. Statistical Analysis Statistical analyses were performed using SPSS 17.0 (SPSS, Inc., Chicago, Ill.) and Graph- Pad Prism 5 software (GraphPad Software, Inc., La Jolla, Calif.). Data are shown as mean ± SD unless stated otherwise. Group comparisons were performed using the Mann-Whitney U test when applicable. Values of p < 0.05 were considered to be statistically significant. A binary logistic regression model with the dependent variable of twitching was computed to calculate the odds ratio of the independent variable length of resection. A chisquare test was used to calculate the difference in distribution of the dependent variables between groups. A receiver operating characteristic curve was plotted to illustrate the sensitivity and specificity of the independent variable to predict twitching at a certain time point Fig. 1. (Left) Intraoperative image demonstrating latissimus dorsi pedicle and thoracodorsal nerve before resection. (Right) Resected thoracodorsal nerve (5 cm).

3 Volume 134, Number 6 Denervation of the Latissimus Dorsi Flap RESULTS In 56 patients (75.7 percent), the latissimus dorsi muscle was denervated at the time of surgery, whereas the thoracodorsal nerve remained intact in 18 patients (24.3 percent). Both groups were comparable with regard to age (50.7 ± 9.6 years and 48.0 ± 13.6 years, respectively). No instance of partial or total flap loss was observed. In cases of denervation, the mean resection length in the first group was 2.97 ± 1.82 cm. In six patients, the nerve was transected but no excision was performed. At 12- and 24-month follow-up, all patients with an intact nerve showed twitching of the muscle. When twitching was present, it was always detectable by both the physician and the patient. In the group where the latissimus dorsi muscle was denervated at the time of surgery, 50 percent of the patients showed twitching at 12 months and 67.9 percent of patients had twitching at 24 months. When the twitching and nontwitching groups were compared at 12 months, a significant difference was found with respect to the length of resection (p < 0.001). This effect was even stronger at 24 months (p < 0.001). The percentage of twitching in the implant plus latissimus dorsi group was 74.2 percent, whereas the percentage of twitching in the latissimus dorsi without implant group was 72.1 percent. Interestingly, no patient had signs of twitching if more than 4 cm of the nerve had been excised at either postoperative time point. Therefore, a nerve resection length of more than 4 cm can be considered as sufficient for the denervation procedure. We calculated a binary logistic regression model to show a possible causal effect of the length of the resected part on the occurrence of twitching. We found an odds ratio of (p = 0.001) at 12 months and per cm resected at 24 months (p = 0.002). This result indicated a progressively reduced risk of twitching for every centimeter resected at the time of surgery. To evaluate the sensitivity and the specificity of the independent variable, centimeter nerve resected, we performed receiver operating characteristic curve analyses and found an area under the curve of (p < 0.001) at 12 months and (p < 0.001) at 24 months. These findings indicated an excellent predictive value (Fig. 2). DISCUSSION Breast reconstruction aims to restore the symmetry of both breasts after partial or total mastectomy to achieve improvements in cosmesis and quality of life. 20 Although breast reconstruction with abdominal or gluteal-based flaps is not prone to twitching, this is often the case when the latissimus dorsi muscle is used. Twitching of the breast after latissimus dorsi reconstruction does not affect every patient, but for those patients with twitching breasts, this issue can influence the overall result. Therefore, preventing the breast distortion that results from latissimus dorsi muscle contraction would contribute greatly to patient satisfaction. 13 Interestingly, there is a lack of data on the optimal method of latissimus dorsi muscle denervation to eliminate the risk of reinnervation. One can presume that transecting the thoracodorsal nerve leads to sufficient denervation of the latissimus dorsi muscle. However, twitching of the latissimus dorsi muscle reappeared in 100 percent of the cases in our study. When parts of the nerve were resected, the risk for recurrence decreased significantly, depending on the length of nerve Fig. 2. Scatterplots to demonstrate the importance of the length of nerve resected for twitching in the latissimus dorsi flap postoperatively at 12 and 24 months (both p < 0.001). 1127

4 Plastic and Reconstructive Surgery December 2014 resection. Our results clearly demonstrate that permanent sufficient denervation of the latissimus dorsi muscle was achieved when more than 4 cm of the thoracodorsal nerve was resected. However, in all other patients, reinnervation increased from 50 percent after 1 year to 67.9 percent 2 years after denervation. This phenomenon could be caused by decelerated reinnervation along the vascular pedicle because of the missing neural tube. The question of when to denervate the latissimus dorsi muscle is an ongoing discussion. In our experience, the procedure should be performed in primary reconstructive cases because of absence of scarring and wide exposure of the neurovascular pedicle. 21 Scarring is usually present in secondary reconstructions with axillary clearance or lymph node biopsies, and indeed, some authors consider latissimus dorsi denervation in these situations as a risk for flap survival. 11,12 Halperin et al. 14 prefer a delayed procedure to minimize the risk of flap loss in case of pedicle injury, as the flap has a secondary blood supply. In our series, denervation was performed during the breast reconstruction procedure in the majority of cases. Denervation-related complications including flap loss or the need for a microsurgical repair were not observed, which indicated that the denervation procedure was safe in our unit, even with nerve resections of over 4 cm. Some authors favor preservation of the thoracodorsal nerve to prevent loss of volume and secondary asymmetry. 11,12 In our experience, volume changes occur regardless of denervation because of the routine detachment of the muscle from its insertion and origin and its resulting inactivity. This observation has been supported by the findings of Kääriäinen et al. and Szychta et al., who observed no difference in volume loss regardless of whether the thoracodorsal nerve was transected or not. 22,23 In addition, Szychta et al. showed in a prospective study that patients with latissimus dorsi muscle denervation achieved lower scores for painfulness and animation and higher scores of overall satisfaction with their reconstructed breasts. 23 Therefore, denervating the latissimus dorsi muscle at the time of breast reconstruction does not appear to impair the final result. Loss of volume as a result of muscle atrophy is not unexpected and can be mitigated against in the initial planning phase. Moreover, the inclusion of a layer of fat over the muscle during harvesting increases the volume of the flap and can minimize the effect of muscle atrophy on the shape of the breast. 24 In cases with extensive volume loss or breast outline distortion, lipofilling is an excellent second-stage method of correcting asymmetry. 25 In our patients, this was performed in only a few cases, which confirmed that volume loss was not a major issue after latissimus dorsi muscle denervation. However, changes in latissimus dorsi muscle volume were not determined objectively, which can be considered a limitation of this study. Nerve resection length could be limited by the anatomical site of the neurovascular pedicle or scarring of the axilla after axillary clearance. Because of the retrospective character of this study, randomization of patients and evaluation of the actual level of discomfort caused by twitching was not possible, which could be considered a study limitation. However, to date, there has not been a single article that has dealt with this issue in a retrospective or prospective fashion. The unfortunate complication of a painful neuroma should always be considered when dissecting a nerve and, as a consequence, some surgeons refuse to dissect the thoracodorsal nerve. However, the thoracodorsal nerve does not have a sensory branch and therefore pain as a consequence of neuroma formation is highly unlikely. Nevertheless, the risk of damaging a sensory intercostal nerve during breast reconstruction with a latissimus dorsi flap must be considered. In our series, no patient suffered either from a neuroma or from any loss of sensation caused by a plexus injury or irritation. CONCLUSIONS Our results demonstrate that denervation of the latissimus dorsi muscle is a safe and reliable procedure. Furthermore, the results of this retrospective study suggest that, if desired, denervation should be performed at the time of breast reconstruction and should include a resection of more than 4 cm to achieve a nontwitching breast with a stable volume and shape. Werner Haslik, M.D. Division of Plastic and Reconstructive Surgery Department of Surgery Medical University of Vienna Waehringer Guertel A-1090 Vienna, Austria werner.haslik@meduniwien.ac.at REFERENCES 1. Olivari N. The latissimus flap. Br J Plast Surg. 1976;29: Hammond DC. Latissimus dorsi flap breast reconstruction. Clin Plast Surg. 2007;34:75 82; abstract vi. 3. Schneider WJ, Hill HL Jr, Brown RG. Latissimus dorsi myocutaneous flap for breast reconstruction. Br J Plast Surg. 1977;30:

5 Volume 134, Number 6 Denervation of the Latissimus Dorsi Flap 4. Bonomi S, Salval A, Settembrini F, et al. Autologous latissimus dorsi flap as an alternative to free abdomen-based flap for breast reconstruction in the morbidly obese. Plast Reconstr Surg. 2012;129:357e 358e. 5. Bonomi S, Settembrini F, Salval A, Gregorelli C, Musumarra G, Rapisarda V. Current indications for and comparative analysis of three different types of latissimus dorsi flaps. Aesthet Surg J. 2012;32: Hammond DC, Simon AM, Khuthaila DK, et al. Latissimus dorsi flap salvage of the partially failed TRAM flap breast reconstruction. Plast Reconstr Surg. 2007;120: Freeman ME, Perdikis G, Sternberg EG, TerKonda SP, Waldorf JC. Latissimus dorsi reconstruction: A good option for patients with failed breast conservation therapy. Ann Plast Surg. 2006;57: Disa JJ, McCarthy CM, Mehrara BJ, Pusic AL, Cordeiro PG. Immediate latissimus dorsi/prosthetic breast reconstruction following salvage mastectomy after failed lumpectomy/irradiation. Plast Reconstr Surg. 2008;121:159e 164e. 9. Seyfer AE, Fox JP, Hamilton CG. Poland syndrome: Evaluation and treatment of the chest wall in 63 patients. Plast Reconstr Surg. 2010;126: Bobin JY, Delay E, Rivoire M. Reconstruction of severe breast deformities following conservative cancer surgery and radiation therapy with a latissimus dorsi myocutaneous flap. Surg Technol Int. 1994;3: Munhoz AM, Montag E, Fels KW, et al. Outcome analysis of breast-conservation surgery and immediate latissimus dorsi flap reconstruction in patients with T1 to T2 breast cancer. Plast Reconstr Surg. 2005;116: Hao L, Clarke CP. Persistent twitching of the latissimus dorsi muscle after a posterolateral thoracotomy. ANZ J Surg. 2002;72: Figus A, Mazzocchi M, Dessy LA, et al. Treatment of muscular contraction deformities with botulinum toxin type A after latissimus dorsi flap and sub-pectoral implant breast reconstruction. J Plast Reconstr Aesthet Surg. 2009;62: Halperin TJ, Fox SE, Caterson SA, et al. Delayed division of the thoracodorsal nerve: A useful adjunct in breast reconstruction. Ann Plast Surg. 2007;59: McCraw JB, Papp C, Edwards A, McMellin A. The autogenous latissimus breast reconstruction. Clin Plast Surg. 1994;21: Papp C, McCraw JB. Autogenous latissimus breast reconstruction. Clin Plast Surg. 1998;25: Theeuwes HP, Gosselink MP, Bruynzeel H, Kleinrensink GJ, Walbeehm ET. An anatomical study of the length of the neural pedicle after the bifurcation of the thoracodorsal nerve: Implications for innervated free partial latissimus dorsi flaps. Plast Reconstr Surg. 2011;127: Wong MT, Lim AY, Coninck CD, Kumar PV. Functional units within the latissimus dorsi muscle based on Sihler technique. Ann Plast Surg. 2007;59: Kelly BT, Kadrmas WR, Kirkendall DT, Speer KP. Optimal normalization tests for shoulder muscle activation: An electromyographic study. J Orthop Res. 1996;14: Guyomard V, Leinster S, Wilkinson M. Systematic review of studies of patients satisfaction with breast reconstruction after mastectomy. Breast 2007;16: Paolini G, Longo B, Laporta R, Sorotos M, Amoroso M, Santanelli F. Permanent latissimus dorsi muscle denervation in breast reconstruction. Ann Plast Surg. 2013;71: Kääriäinen M, Giordano S, Kauhanen S, et al. The significance of latissimus dorsi flap innervation in delayed breast reconstruction: A prospective randomized study-magnetic resonance imaging and histologic findings. Plast Reconstr Surg. 2011;128:637e 645e. 23. Szychta P, Butterworth M, Dixon M, Kulkarni D, Stewart K, Raine C. Breast reconstruction with the denervated latissimus dorsi musculocutaneous flap. Breast 2013;22: Bailey SH, Saint-Cyr M, Oni G, et al. The low transverse extended latissimus dorsi flap based on fat compartments of the back for breast reconstruction: Anatomical study and clinical results. Plast Reconstr Surg. 2011;128: 382e 394e. 25. Schultz I, Lindegren A, Wickman M. Improved shape and consistency after lipofilling of the breast: Patients evaluation of the outcome. J Plast Surg Hand Surg. 2012;46: