Split Chest Breast Neurotization

Study Overview
=================
Brief Summary
-----------------
Several members of the scientific community have suggested that breast neurotization can help return nipple sensation to patients undergoing implant-based breast reconstruction. There has been no randomized controlled study assessing the validity of these claims. The goal of this study is to evaluate if performing breast neurotization can help restore or improve return of nipple sensation to patients undergoing implant-based breast reconstruction. This will be a single-blinded, randomized controlled trial where patients undergoing bilateral reconstruction will serve as their own controls by receiving an intervention on one breast but not the other breast.

Official Title
-----------------
A Single-Blind, Split-Chest, Single-Center Study of the Effects of Breast Neurotization in Implant Based Breast Reconstruction

Conditions
-----------------
Breast Implant; Complications

Intervention / Treatment
-----------------
* Procedure: Sensory Nerve Coaptation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Women undergoing bilateral nipple-sparing mastectomy (prophylactic or therapeutic) at a single institution Women receiving implant-based reconstruction (either direct to implant or tissue expander-based implant reconstruction of any size) Age 18 or older Exclusion Criteria: Women with history of prior breast surgery given concern for potentially damaged nerves by prior intervention that could impact the procedure and results. Procedures include but are not limited to: prior breast reduction, prior breast augmentation, prior lumpectomy Pre-operative radiation or anticipated post-operative radiation Body Mass Index (BMI) > 30 kg/m2 or patients with macromastia (larger breasts) as these patients frequently require larger implants that will not accommodate the longest nerve graft available (70 mm) Current tobacco or nicotine use History of diabetes mellites with a HgbA1c > 7% due to lower rates of wound healing History of auto-immune disease History of allergy, sensitivity, or intolerance to porcine-derived materials Intraoperatively, patients may have to be excluded if during the mastectomy the lateral nerve targets were severely damaged or removed as part of the mastectomy. While these patients will be excluded from the formal analysis, the investigators will continue to follow them as a subgroup for analysis and comparison. Men as they infrequently receive bilateral mastectomies due to breast cancer. Male breast cancer is <1% of all breast malignancies. Pregnancy as determined by urine pregnancy test on day of surgery

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Neurotized Breast<br>For patients undergoing bilateral implant-based breast reconstruction following nipple-sparing mastectomy, one breast will be neurotized by connecting the lateral intercostal nerve to the nipple with interposing standard nerve grafting techniques. The neurotized breast will serve as the experimental breast. The other breast will not receive any breast neurotizing procedure. | Procedure: Sensory Nerve Coaptation<br>* Nerve reconstruction will employ an off-the-shelf nerve graft coapted to the donor anterior intercostal nerve branch laterally and medially at the underside of the nipple. The anterior intercostal nerve branch and nerve graft coaptation will be performed in a standard fashion with a 1 mm gap between the ends of the graft and the donor nerve. Medially, the nerve graft will be inset into the underside of the preserved nipple-areola complex using 8-0 or 9-0 epineural stitches from the nerve allograft. All nerve coaptations will be performed under loupe magnification as is standardly performed.<br>|
| No Intervention: Non-Neurotized Breast<br>For patients undergoing bilateral implant-based breast reconstruction following nipple-sparing mastectomy, one breast will not receive any breast neurotizing procedure. The non-neurotized breast will serve as the control breast. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Semmes-Weinstein Monofilament Testing (SWMT) Score in the Nipple (Area 9) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Nipple (Area 9) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SWMT Score in the Mastectomy Superior (Area 1) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Mastectomy Superior (Area 1) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Mastectomy Lateral (Area 2) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Mastectomy Lateral (Area 2) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Mastectomy Inferior (Area 3) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Mastectomy Inferior (Area 3) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Mastectomy Medial (Area 4) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Mastectomy Medial (Area 4) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Flap Superior (Area 5) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Flap Superior (Area 5) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Flap Lateral (Area 6) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Flap Lateral (Area 6) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Flap Inferior (Area 7) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Flap Inferior (Area 7) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery | 
| SWMT Score in the Flap Medial (Area 8) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 12 Post-Surgery | 
| SWMT Score in the Flap Medial (Area 8) | SWMT will be used for assessment of breast sensation by applying the monofilament to a given anatomic region. Based on the monofilament size, a score of 0-6 is assigned. Scores are classified as follows: 6 = normal; 5 = diminished light touch; 4 = diminished protective sensation; 3 = loss of protective sensation; 2 = Loss of protective/sensation; 1 = Deep pressure sensation only; and 0 = Loss of sensation. | Month 24 Post-Surgery |