The QUILT study: quilting sutures in patients undergoing breast cancer surgery: a stepped wedge cluster randomized trial study

This is the first multicentre prospective study in which quilting without postoperative wound drain will be compared with conventional wound closure with postoperative wound drain following mastectomy and/or axillary lymph node dissection (ALND) with textbook outcome as primary outcome.

To investigate the effect of quilting on quality of health care, a primary outcome parameter is proposed that reflects all relevant parameters and is also suitable for a sample size calculation based on available data from previous studies.

Although often used in previous studies as a primary end-point, seroma can be difficult to define and interobserver variability is likely to occur. Ultrasound could be used to diagnose seroma, however, potential over diagnosis of clinically insignificant small fluid collections would obscure the results. In previous publications the term “clinically relevant seroma” was used to identify those collections necessitating outpatient drainage, often by repeated needle aspiration. This concept is however prone to interobserver subjectivity and physicians’ preference. For these reasons a combined endpoint was defined as an uneventful postoperative course, a so-called textbook outcome following mastectomy and or axillary dissection. Textbook outcome is a multidimensional measure, reflecting an uneventful course following mastectomy and/or ALND. The definition of textbook outcome was established in consultation with surgeons from different hospitals. In this study textbook outcome implies a postoperative course proceeded without wound complications, unscheduled visits to the outpatient clinic, re-admissions, re-operation nor increased use of analgesics compared to pre-operative, measured 6 months post-operative.

The sample size in the protocol is based on data from a previous performed study in two participating hospitals: CWZ and RH [7]. The incidence of textbook outcome was determined from data in both hospitals, where one hospital (CWZ) applied quilting sutures without postoperative drainage as standard practice and the other hospital (RH) used conventional wound closure with postoperative drainage as standard practice.

Surgeons from several hospitals have expressed their interest in learning the technique of quilting, however concerns remain about the impact on overall patient care and health care consumption. Participating in this stepped wedge study enables the combination of implementation of a uniform technique and monitoring the effects of implementation on patient and hospital level. A multicentre individual randomised controlled trial is deemed less suitable for our objectives. Advantage of a stepped wedge design is the immediate implementation of a technique in case of an established positive effect. Furthermore, the learning curve is expected to be steeper compared to alternating the new and old technique. In addition, in the setup of an individual randomised trial patients might deny trial participation and opt for their preferred treatment, either quilting or not. Moreover, the individual randomised trial comes with a higher burden for hospital staff to gain individual informed consent, perform individual randomisation and obtain case report forms. Beside, trial monitoring by investigators is expected to be more time consuming for a randomized trial compared with a stepped wedge study, and thus more expensive. On account of the aforementioned considerations we opted for a stepped wedge study.

While wound closure using quilting sutures is relatively simple, this technique has the potential to change daily clinical practice. We hypothesize that quilting reduces the complication burden of treatment in patients undergoing mastectomy and/or axillary lymph node dissection. We expect the impact on healthcare costs to be beneficial. Prior retrospective data suggest the quilting suture technique takes an additional ten minutes surgery time (estimated cost €160), but shortens hospital stay from inpatient admission to treatment in day care (estimated gain €400), omitting a wound drainage system (€40) and preventing visits to the outpatient clinic for seroma aspiration (€75 per visit with aspiration) [6, 20]. In the Netherlands, where each year 30% of 17.000 women diagnosed with breast cancer undergo mastectomy without immediate reconstruction, this could add up to an annual saving of approximately €1.8 million. Numbers of axillary lymph node dissection, multiple seroma aspirations, impact of surgical site infections, wound dressings, re-admissions or other societal costs such as travelling and work leave among others are not yet taken into account. Therefore, an auspicious beneficial impact is expected in healthcare consumption and thus healthcare costs. However, the magnitude of this budgetary impact remains to be proven in a larger population, preferably over different hospitals.

Previously, concerns have been raised about possible unwarranted side effects of flap suturing following mastectomy and/or ALND. One can imagine that skin flap fixation could impact shoulder range of motion or that multiple sutures can be painful. In case of a thin subcuticular layer, there could be visible skin dimpling at the site of the sutures. In a small prospective dual centre study comparing CWZ and RH, no significant difference between quilted and non-quilted patients was found regarding postoperative shoulder function and postoperative pain and use of analgesics [7]. The QUILT study will report on shoulder function and cosmetic satisfaction from a patients and surgeons perspective in a sufficiently large population. The evaluation will be conceived as extended patient reported outcome measures in the form of standardized and validated questionnaires taken at several points in time. The large patient group and the fact that different institutions and surgical teams participate should enable robust and generalizable conclusions.

Other study protocols regarding postoperative care in breast cancer have been published, such as the SAM trial [39] or the QUISERMAS trial [18]. The SAM trial, a double blind randomized controlled trial, compares flap fixation by quilting sutures with postoperative drainage to conventional wound closure with drainage and to flap fixation by fibrin glue with wound drainage [5]. Flap fixation by sutures following mastectomy leads to a reduction of CSS compared to patients who underwent conventional wound closure or flap fixation by tissue glue. Furthermore unplanned visits were less in the quilted cohort. There were no differences in postoperative shoulder function and cosmetics.

In the QUISERMAS trial, a multicentre, randomized controlled trial, quilting sutures without drainage is compared to conventional wound closure with drainage. In the QUISERMAS trial shoulder function is not assessed by the patient. The range of shoulder movement is reported by the surgeon and cosmetics are assessed by an independent committee. Results of the QUISERMAS trial are awaited.

In conclusion, this study aims to evaluate the effect of implementation of the quilting suture technique in breast cancer surgery. A relatively simple and promising technique that seems effective in reduction of seroma and other wound complications, which are frequently reported following mastectomy and/or ALND. We hypothesize that quilting is a simple technique to decrease the complication burden of treatment and health care consumption. The results of this stepped wedge study will be an important contribution to further explore the quilting technique in order to become an established technique in breast surgery.