Introduction

Breast cancer is a widespread problem for women in industrialized nations; the lifetime risk is one in eight for Americans ("Breast Cancer Facts and Figures" 2002). The current treatment often involves disfiguring mastectomies, which are usually psychologically distressing to women (Mock 1994). Fortunately, reconstructive plastic surgeons can improve the quality of life outcome by providing substitute breasts for mastectomy patients. While reconstructive breast surgery clearly aids the mastectomy patient psychologically, there are questions regarding the patient's physical state after breast reconstruction, specifically following the free transverse rectus abdominis myocutaneous (TRAM) flap operation.

TRAM flap surgery involves removal of part of the transverse rectus abdominis muscle and the surrounding skin and fat. The island of skin, fat, and muscle is removed with the dissection of the attached blood vessels and then molded into a breast form on the patient's chest. The blood vessels are usually attached to the thoracodorsal or internal mammary arteries through microsurgery. The TRAM flap surgery is sometimes referred to as the "tummy-tuck" reconstruction because it can result in a flatter stomach. Sometimes, a synthetic mesh overlay is used as reinforcement if the abdomen is pulled too tight (Walker 2000).

It is not uncommon to find patients who experience problems with their upper extremities, including shoulder joint stiffness and muscle shortening, after this surgery (Thomas 1993). Muscle groups and joints near the involved site may be weak and inflexible as a result of the surgery. The upper extremity problems may last anywhere from a couple of weeks to some years. Patients may experience mild to severe problems with range of motion or frequent pain sensation. Physical therapy as soon after surgery as possible is the accepted solution to prevent and correct such problems. Yet the ideal time to begin therapy after TRAM flap surgery is not standardized. Presently, surgeons are generally hesitant to prescribe physical therapy if the patient is still producing significant amounts of drainage from their wound catheters as exercise may stimulate lymphatic flow and increase drainage. High volumes of drainage output is one of the factors, like low blood count, fatigue, joint, or bone pain, that can hinder a patient's rehabilitation schedule. Therefore, patients who produce greater drainage outputs must wait longer to begin therapy than those who produce less drainage.

Although surgical drains were first used in mastectomy patients as early as 1947 (Murphey 1947), medical knowledge concerning drainage output is relatively limited. Few studies have been performed on different aspects of postoperative drainage. For example, one study by Petrek et al. demonstrated that the number of surgical drains (single vs. multiple) has no correlation with the amount of drainage output after lymphadenectomy (1992). Another study by Terrell and Singer (1992) found no significant correlation between the location of the drain(s) (axillary vs. combined axillary and pectoral drains) and the amount of drainage after modified radical mastectomy.

In order to help physicians predict when patients should begin physical therapy, this study examined different variables that could correlate with drainage output. Specially, the patient's age, body mass index (BMI), and side of reconstruction (left vs. right) after TRAM flap surgery were tested for a correlation with drainage output.

The hypothesis was that the younger and more active patients would produce more drainage than the older and more sedentary patients. The reasoning behind this idea is that with increased activity there is increased cardiac output, which results in more blood flowing to the tissues and more fluid in the interstitial space, lymphatic drainage. It was also expected that people with larger BMIs would have more drainage than those with lower BMIs. This supposition derived from the basic premise that larger people are capable of producing more drainage than smaller people. Finally, it was hypothesized that side of reconstruction should bear no correlation with drainage output. This assumption was based on the anatomical likeness of both the right and left axillae.

Patients and Methods

Eighty-five patients ranging in age from 25 to 63 years (mean age: 47.6) who underwent free TRAM flap surgeries consecutively at M.D. Anderson hospital between the dates of January 3, 2000 and January 24, 2001 were used in this retrospective study. The patients differed in the types of reconstruction they underwent: left unilateral free TRAM flaps, right unilateral free TRAM flaps, or bilateral free TRAM flaps. Except for three cases, all of the patients chose immediate reconstructions following their mastectomies, as immediate reconstruction provides various advantages and does not seem to increase the risk of recurrence (Kroll et al. 1991). Of the three who underwent delayed reconstruction, one was a woman with a left unilateral free TRAM flap, and the other two were women who had bilateral free TRAM flaps as an immediate right-side reconstruction but a delayed left-side reconstruction. Except for five cases, all of the patients had microsurgery performed on their thoracodorsal vessels. Four of the five exceptions had left unilateral free TRAM flaps and microsurgery on their internal mammary arteries instead. The fifth exception was a bilateral free TRAM patient whose microsurgery involved using the thoracodorsals on her right side and the internal mammaries on her left side.

Individual BMIs were calculated in kg/m² by dividing the patient's weight (kg) by the square of her height (m). BMIs ranged from 19.1 kg/m² to 39.25 kg/m² (mean: 26.4 kg/m²). BMIs are generally categorized in four groups: those ranging in value between 18.5 and 24.9 are considered normal; those between 25 and 29.9 are considered overweight; those between 30 and 40 are considered obese; and those over 40 are considered morbidly obese (Willett et al. 1999). For this study, however, the patients were divided into three categories: those with BMIs less than 25, those between 25 and 30, and those with BMIs above 30.. To examine the variable of age, patients were grouped by decade. To properly isolate the effects of age, all other factors were kept the same so that each patient group underwent the same extent of axillary dissection, the same side of reconstruction, and used the same type of recipient vessels. The patients' inpatient drainage outputs (cc) were determined upon examining the nursing notes, in which nurses and hospital staff maintain daily records of the drainage outputs during the standard five days of hospitalization. As this study involved breast drains only, the first drain was placed in the patient's axilla and if a second drain was needed, it was placed under the mastectomy flap. Thus, total drainage is the aggregate sum of fluid in all breast drains in the patient regardless of their placements.

An ANOVA test was used to determine the relationship between age and total drainage output and the relationship between side of reconstruction and total drainage output. The relationship between BMI and total drainage output was determined using Bartlett's test for equal variances.

Figure 1. No correlation between age and total drainage output.





Figure 2. Left side produces more drainage (p = 0.0111).






Figure 3. Slight positive correlation between BMI and total drainage output for low and high BMIs.