The Use of a High-frequency Ultrasonic Knife in Breast Cancer Surgery
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Study type: Interventional

Summary: 
      Background: Lymphatic stasis and seroma formation are common complications of axillary
      lymphadenectomy in breast cancer surgery. The investigators aim is to test the hypothesis
      that the use of an ultrasonic knife for axillary dissection reduces the total amount and
      duration of persistent drainage and length of hospital stay. Method: The investigators have
      conducted a randomized trial on 94 patients (1 male, 93 females, mean age 64.7 years) who
      presented to the investigators unit with operable breast carcinoma. Patients in group A (38
      cases) were operated on using exclusively the ultrasonic knife. Patients in group B (56
      cases) were operated on using the conventional diathermy knife.
    

Detailed description: 
      The ultrasonic knife we have used in our study exploits the electrical impulses produced by a
      high-frequency ultrasound generator, transferred to a hand piece and converted into a
      mechanical movement at a frequency of 55.5 kHz (11,12) (Ultracision®, Ethicon Endo Surgery ).
      We have chosen this instrument because the relatively low temperatures generated in the
      process, ranging from 50 to 100 °C, result in a coagulative necrosis which allows both
      cutting and effective sealing of blood and lymphatic vessels, therefore preventing lymphatic
      leaks more effectively compared with conventional diathermy. The latter produces temperature
      up to 400 °C resulting in char formation and deleterious thermal effects to a distance of up
      to 1cm from the blade and extensive formation of necrotic tissue.

      We have estimated Using the data of a previous unpublished pilot study, the sample size
      required for our trial using the data of a previous unpublished pilot study, indicating that
      to detect a significant difference in length of stay (delta = 4of four days, with a mean
      standard deviationsdigma of = 4.5 days, between the two groups with a level of significance
      of alpha = 5% and a power of1 - beta = 90%), we needed to enroll was estimated in 28 patients
      in each group arm. As a precaution we decided to increase the sample size by 25% to 35
      patients per group arm, in case we needed to use non-parametric tests in subsequent
      statistical analysis. A total of 94 patients with operable breast carcinoma were recruited
      between January 2000 and December 2004: 1 male and 93 females (min 34, q1 58, median 65, mean
      64.7, q3 73, max 95). All patients underwent total mastectomy or quadrantectomy and 1st or
      2nd level axillary lymphadenectomy. Patients were randomly allocated to two treatment groups:
      patients allocated to Group A were operated on using exclusively the ultrasonic knife
      (Ultracision®, Ethicon Endo Surgery) for both the mastectomy or quadrantectomy and axillary
      dissection (38 cases, mean age of 64.6 years, min 34, q1 58, median 66, q3 70, max 95);
      patients allocated to Group B (control group) were operated on using a conventional
      diarthermy knife was (56 cases, mean age of 65.0 years,min 37, q1 59, median 65, q3 74, max
      89). In all cases the type of a redon n°14 suction drain was left in the axillary cavity and
      removed as soon as the amount of fluid dropped to 35 ml/24h or less. The patient was
      discharged home the same day the drain was removed.

      During the postoperative period the following data were collected: the total amount of fluid
      drained, the number of days the drain was leftof drainage, the length of post-operative stay,
      and early and late complications. Early complications were specifically recorded: wound
      seromas and hematomas, wound infections, necrosis of wound margins and period of time (in
      days) the seroma needed to be needle-aspirated following removal of the drain. Late
      complications recorded were lymphedema, strength and sensation deficits and chronic arm pain.
      A cost analysis was also done considering materials employed and length of hospital stay.
      Statistical analysis was done using open source "R" software, version 2.5.1 (18). The
      Shapiro-Wilk test was used to verify the normal distribution of data; heteroscedastic,
      normally distributed data were analysed using the F-test of variance; Student's t test was
      used for homoscedastic data. For non normally distributed data the non-parametric
      Wilcoxon-Mann-Whitney test was used. Survival analysis was analysed using Cox's regression
      model, in the hypothesis of proportional risk.
    

Intervention name(s): ultrasonic knife (Ultracision®, Ethicon Endo Surgery); conventional diarthermy knife
Intervention type(s): Procedure; Procedure
Intervention description(s): mastectomy or quadrantectomy and axillary dissection by an ultrasonic knife (Ultracision®, Ethicon Endo Surgery); mastectomy or quadrantectomy and axillary dissection using conventional diarthermy knife
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: breast cancer; ultrasonic knife; volume drainage