Selective Intraoperative Administration of Local Anesthesia in Breast Reconstruction
Condition: Breast Cancer
Study type: Interventional
Phase: Phase 2

Summary: 
      Subjects are being asked to participate in this study because they will be undergoing
      unilateral (one) or bilateral (two) mastectomy surgery with immediate reconstruction
      involving insertion of a tissue expander.
    

Detailed description: 
      One in eight women will develop breast cancer in her lifetime, and many of these women
      undergo mastectomy followed by breast reconstruction by insertion of a tissue expander below
      the pectoralis major muscle. Women undergoing breast reconstruction have been shown to have a
      significantly higher level of acute postoperative pain and postoperative narcotic requirement
      compared to women who undergo mastectomy alone without reconstruction. In addition to the
      inherently worthwhile end of providing patient comfort in the immediate postoperative period,
      decreased narcotic use carries with it the potential benefit of decreasing the incidence of
      other adverse effects such as nausea, vomiting, allergic reaction, and respiratory
      depression.

      Importantly, the intensity of pain in the immediate postoperative period has been implicated
      as an important factor predisposing patients to the development of chronic postoperative
      pain. Chronic pain following mastectomy is a significant and disabling problem, affecting up
      to 49% of patients in some series. Though breast reconstruction has been shown not to be an
      independent predictor of the development of chronic breast pain, improved control of acute
      pain in the immediate postoperative period carries significant promise in decreasing the
      incidence of this disabling condition for all breast cancer survivors treated with
      mastectomy. In addition, improving management of acute postoperative pain can shorten
      hospital stay, expedite return to daily normal activities and increase patient satisfaction.

      A variety of other adjuncts for pain control have been attempted in studies of variable
      methodological rigor, including injection of botulinum toxin into the pectoralis muscle,
      indwelling pain catheters, paravertebral blocks under ultrasound guidance, or simple
      irrigation of the general area of dissection during breast surgery with a solution containing
      local anesthestic. While each of these adjuncts has demonstrated some success, none has been
      widely adopted. Problems with these methods include cost, risk of adverse events, as well as
      anatomically incomplete or non-selective application.

      During mastectomy all breast tissue is removed, leaving the patient with denervated skin
      flaps. For breast reconstruction, a tissue expander is placed in a subpectoral pocket
      dissected between the pectoralis major and minor muscles. At the end of the procedure the
      pectoralis major muscle is placed under variable degree of tension depending on the amount of
      fluid placed inside the expander. This muscle stretch believed to be at least partially
      responsible for postoperative pain. In addition cut nerve endings in the superficial fascia
      likely contribute as well. The anatomy of nerves supplying the breast and involved muscles
      are well-described in rigorous cadaver studies.

      In this study we hypothesize that performing a block of the intercostal nerves responsible
      for innervating the breast tissue and skin and the pectoral nerves innervating the pectoralis
      major muscle should optimize immediate postoperative pain control in this patient population.
      Of adjuncts described in the literature, paravertebral blocks are the most anatomically
      targeted, but drawbacks include the need for a separate procedure preoperatively while the
      patient is awake by an anesthesiologist with facility performing these blocks as well as the
      risk of pneumothorax. Advantages of our proposed method include lack of pain as the patient
      is asleep, easy and speed of application, a decreased risk of pneumothorax as the injections
      are under direct visualization, as well as a decrease in cost and improved efficiency as the
      only a single provider (i.e. the operative surgeon) is required. Precedent for our technique
      has been described in the context of breast augmentation and breast lift, with a favorable
      safety profile and providing adequate analgesia to perform these procedures without the use
      of a general anesthetic.
    

Intervention name(s): Saline; 0.25 % bupivacaine (2.5 mg/ml) w/ 1:100,000 epinephrine & 4 mg dexamethasone
Intervention type(s): Drug; Drug
Intervention description(s): If randomized to this arm, subjects will receive an intraoperative injection of saline. (2.5 mg/ml); If randomized to this arm, subjects will receive a selective block with a local anesthetic solution containing 0.25 % bupivacaine.
(2.5 mg/ml) with 1:100,000 epinephrine and 4 mg dexamethasone intraoperatively.
Other intervention name(s): Sodium Chloride 0.9%; Bupivacaine
Intervention MeSH terms: Dexamethasone; Epinephrine; Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Breast Reconstruction; Mastectomy