Abstract
Background:
The circulation of the pedicled transverse rectus abdominis myocutaneous (TRAM) flap is often poor in zone IV, which is usually excised. Indocyanine green (ICG) dye analysis is a modality that can help surgeons predict and remove insufficient tissue perfusion areas. This retrospective study (ICT study) compared clinical flap outcomes following pedicled TRAM flap reconstruction with or without ICG fluorescence imaging.
Methods:
Patients who underwent pedicled TRAM flap reconstruction from January 2003 to March 2024 were included. In cases using ICG guidance, the boundary of zone IV was identified and separated according to the ICG enhancement.
Results:
A total of 301 patients were studied, with 254 in the non–ICG group and 47 in the ICG group. The overall flap complication rate was 22.9%. In the non–ICG group, we found 61 in total, of which 40 had mild fat necrosis, 19 had severe fat necrosis, 1 had partial flap loss, and another had complete flap loss. In the ICG group, among 8 patients with complications, 4 had mild fat necrosis and 4 had severe fat necrosis, and no flap losses occurred. There was no significant difference between the groups. Complications were associated with a BMI over 25 and postoperative radiation. In 8 patients (17%), using ICG allowed more of the zone IV area to be preserved, but did not significantly affect flap complications.
Conclusions:
ICG fluorescence imaging is not significantly different from an anatomy-based technique in pedicled TRAM flap reconstruction, but it still helps surgeons to identify insufficient perfusion areas, leading to a lower incidence of flap complications. High BMI and postoperative radiation are related to flap complications.
Takeaways
Question: What is the clinical utility of indocyanine green (ICG) fluorescence imaging in determining the area to be excised in pedicled TRAM flap breast reconstruction?
Findings: No significant difference in postoperative complications was observed between cases with and without ICG use. ICG allowed preservation of more of the zone IV area of the transverse rectus abdominis myocutaneous flap in some patients, which did not significantly affect flap complications.
Meaning: Using intraoperative ICG does not change postoperative complications but can potentially preserve more flap tissue for reconstruction without increasing complications.
INTRODUCTION
Pedicled transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction is widely used in breast cancer surgery worldwide. A case series and description of surgical procedures for various types of TRAM flaps used in breast reconstruction were first reported in 1982 by Hartrampf et al.1 Conventionally, the TRAM flap relies on the blood flow through the deep superior epigastric artery as a pedicle within the rectus abdominis muscle. A study of vascular anatomy by Moon and Taylor2 described the principle that a pedicled TRAM flap receives an indirect blood supply from the deep superior epigastric artery. Limitations of this indirect blood supply can lead to flap complications, fat necrosis or flap necrosis, which can occur at rates of up to 14%–21% and 5%, respectively.3,4
From a surgical perspective, a unilateral pedicled TRAM flap has an elliptical skin shape that can be divided into 4 zones (zones I–IV) according to their vascularization, a classification first described by Hartrampf et al1 and Dinner et al5 and later modified by Holm et al.6 The circulation of the pedicled TRAM flap is usually poor in the contralateral lateral segment (zone IV) and is typically removed. Zones II and III sometimes do not show standard and reliable patterns of perfusion, probably depending on each patient’s anatomy, previous scarring, and smoking habits.2,5,7,8 Patients with breast cancer with a large chest wall defect may require cutting the flap more laterally to preserve a higher volume of tissue. The current practice for patients with a low midline surgical scar is to remove all tissues beyond the scar, which could further decrease tissue volume.9
Decision-making in TRAM flap reconstruction is influenced by tissue perfusion. Various intraoperative methods have been developed to assess flap perfusion, such as Doppler ultrasound (U/S), laser Doppler, fluorescence imaging, and oxygen saturation measurement. A meta-analysis reported by Smit et al10 found that fluorescence imaging and laser Doppler are the most suitable methods to measure tissue perfusion in free flaps, resulting in improved flap survival. The flap viability prediction modality with indocyanine green (ICG) dye analysis can help surgeons predict and remove areas with insufficient tissue perfusion.7
There have been many studies in Thailand and globally on applying fluorescence imaging to pedicled TRAM flaps. Our institute reported outcomes from using ICG fluorescence imaging to determine the border of the pedicled TRAM flap.9 A total of 29 patients underwent a pedicled TRAM reconstruction. The ICG imaging showed distinct perfusion patterns, termed “YaYa’s classification.” The overall fat necrosis rate in the study was 13.33%, which is similar to the fat necrosis rates in previous studies of conventional pedicled TRAM flap operations (14%–21%),3,9,11 with no flap loss. This retrospective study aimed to compare clinical flap outcomes after pedicled TRAM flap reconstruction with or without ICG fluorescence imaging.
PATIENTS AND METHODS
Patients who underwent breast reconstruction with a pedicled TRAM flap from January 2003 to March 2024 were included. Patients were divided into 2 groups based on whether intraoperative ICG was used. Patients’ age, weight, height, body mass index (BMI), smoking history, and comorbidities were collected from medical records. The study included female patients with breast tumors requiring mastectomy and either immediate or delayed reconstruction. For immediate breast reconstruction, the type of mastectomy was recorded: nipple-sparing mastectomy (NSM), skin-sparing mastectomy, and total mastectomy. Previous abdominal operations, duration of operations, and reconstruction outcomes were also recorded. Patients with previous abdominoplasty, inadequate tissue in the lower abdomen, and substantial weight loss were excluded.
Surgical outcomes focused on fat necrosis and flap loss. Mild fat necrosis was defined as any palpable firmness involving less than one-third of the flap that persisted for more than 3 months after surgery without cancer recurrence, and severe fat necrosis was defined as skin and fat necrosis involving more than one-third of the flap that persisted for more than 3 months after surgery without cancer recurrence. Partial flap loss was defined as skin and fat necrosis involving one-third to two-thirds of the flap, and complete flap loss was defined as skin and fat necrosis involving more than two-thirds of the flap.12 Fat necrosis was evaluated through physical examination (PE) and radiological findings using U/S with mammogram (MMG) by the physician at 3–6 months after the operation. All patients underwent PE and U/S with MMG during follow-up. We also include patients with fat necrosis that was diagnosed by computer tomography (CT) scan in case patients were appointed for either surveillance breast cancer or other reasons. We recorded the diagnostic tool as (1) PE if flap complications were diagnosed by examination, (2) U/S if flap complications were diagnosed by U/S with MMG without positive finding on PE, and (3) CT if CT scans diagnosed flap complication without detecting from PE and U/S.
The primary outcomes were flap loss and fat necrosis in both groups. The secondary outcomes were operative time and donor-site complications, such as surgical site infection rate, wound dehiscence, seroma, and reoperation rate.
Operative Technique
A pedicled TRAM flap was harvested using a standard elliptical incision in the lower abdomen. The abdominal flap was dissected in the direction of the lateral to medial side of the abdomen, identifying arterial perforators along the way. The deep inferior epigastric artery perforators were identified and cut after dividing the rectus muscle at the arcuate line. After fully harvesting the pedicled TRAM flap, we marked the flap zones based on anatomy using the Hartrampf anatomy concept. Zone I was located at the pedicle side, zone II was the contralateral medial section, zone III was the ipsilateral lateral section, and zone IV was the contralateral lateral section of the TRAM flap (Fig. 1A). In the case of using fluorescence guiding, ICG was injected through peripheral intravenous access at a dose of 0.25 mg/kg by anesthesiologists. The perfusion of the flap was visualized using a fluorescence camera (FLUOPTICS) and recorded for 5 minutes. We then separated the flap along the border according to the ICG enhancement, not by anatomy. For non-ICG guides, we cut the flap in areas along zones II and IV using the Hartrampf anatomy concept (Figs. 1B, C). In case of delayed reconstruction, patients underwent reconstruction at least 1–2 years after complete surgery.
Fig. 1.
View of the harvested TRAM flap. A, The pedicled TRAM flap was marked according to anatomical zones using the Hartrampf anatomy concept. B, ICG fluorescent imaging of the pedicled TRAM flap showed no perfusion in the contralateral lateral segment (zone IV). C, Zone IV of the flap was removed according to the border guidance provided by ICG fluorescence imaging. (In this case, the borders defined by anatomical landmarks and ICG imaging were the same.)
Statistical Analysis
Statistical analyses were performed using Stata, version 18 (licensed to Clinical Epidemiology and Biostatistics, Ramathibodi Hospital). All demographic data were summarized using descriptive statistics. Patient characteristics were compared using the Student t test or Mann-Whitney test for continuous variables and the χ2 test or Fisher exact test for categorical variables. Continuous variables were reported as mean and SD or median (range), whereas categorical variables were summarized as counts and percentages. Statistical significance was set at a P value of less than 0.05. Factors associated with outcomes were analyzed using logistic regression.
RESULTS
A total of 301 patients who underwent breast reconstruction using unilateral pedicled TRAM flaps were included in this study: 254 patients in the non-ICG group and 47 patients in the ICG group. The baseline characteristics of patients in each group are shown in Table 1.
Table 1.
Patient Characteristics
| Patient Characteristics | Total (N = 301) | Non-ICG (N = 254) | ICG (N = 47) | P |
|---|---|---|---|---|
| Age, mean (SD), y | 44.98 (8.14) | 44.35 (7.92) | 48.38 (8.59) | 0.001 |
| BMI, kg/m2, n (%) | ||||
| <25 (normal) | 211 (70.10) | 186 (73.23) | 25 (53.19) | 0.006 |
| 25–30 (overweight) | 77 (25.58) | 62 (24.41) | 15 (31.91) | 0.279 |
| >30 (obesity) | 13 (4.32) | 6 (2.36) | 7 (14.89) | 0.001 |
| Diabetes mellitus, n (%) | 17 (5.65) | 9 (3.54) | 8 (17.02) | 0.002 |
| Hypertension, n (%) | 35 (11.63) | 25 (9.84) | 10 (21.28) | 0.043 |
| Smoking, n (%) | 3 (1) | 2 (0.79) | 1 (2.13) | 0.400 |
| Previous incision, n (%) | ||||
| Low transverse | 55 (18.27) | 48 (18.90) | 7 (14.89) | 0.681 |
| Low midline | 20 (6.64) | 16 (6.30) | 4 (8.51) | 0.530 |
| Periumbilical | 5 (1.66) | 5 (1.97) | 0 | 0.999 |
| RLQ (McBurney) | 12 (3.99) | 12 (4.72) | 0 | 0.225 |
| Primary tumor, n (%) | ||||
| Unilateral breast cancer | 285 (94.68) | 242 (95.28) | 43 (91.49) | 0.244 |
| Bilateral breast cancer | 2 (0.66) | 1 (0.39) | 1 (2.13) | |
| Phyllode | 10 (3.32) | 7 (2.76) | 3 (6.38) | |
| Benign | 4 (1.33) | 4 (1.57) | 0 | |
| Tumor stage, n (%) | ||||
| 0 (DCIS) | 28 (11.16) | 23 (11.06) | 5 (11.63) | 0.425 |
| I | 59 (23.51) | 49 (23.56) | 10 (23.26) | |
| II | 110 (43.82) | 95 (45.67) | 15 (34.88) | |
| III + IV | 54 (21.51) | 41 (19.71) | 13 (30.23) | |
| ER positive, n (%) | 177 (71.37) | 148 (72.55) | 29 (65.91) | 0.377 |
| PR positive, n (%) | 145 (58.47) | 118 (57.84) | 27 (61.36) | 0.667 |
| HER2, n (%) | ||||
| 0/1+ | 140 (59.32) | 119 (60.10) | 21 (55.26) | 0.675 |
| 2+ | 35 (14.83) | 30 (15.15) | 5 (13.16) | |
| 3+ | 61 (25.85) | 49 (24.75) | 12 (31.58) | |
| Ki67 >20%, n (%) | 130 (52.42) | 101 (49.51) | 29 (65.91) | 0.066 |
| Chemotherapy, n (%) | ||||
| Neoadjuvant | 26 (10.24) | 15 (7.14) | 11 (25) | 0.001 |
| Adjuvant | 182 (71.65) | 160 (76.19) | 22 (50) | 0.001 |
| RT, n (%) | ||||
| Preoperative | 8 (3.11) | 6 (2.82) | 2 (4.55) | 0.317 |
| Postoperative | 79 (31.10) | 66 (31.43) | 13 (29.55) | 0.806 |
| Postoperative CT imaging, n (%) | 80 (26.57) | 64 (23.62) | 16 (34.014) | |
DCIS, ductal carcinoma in situ; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; PR, progesterone receptor; RLQ, right lower quadrant area of abdomen.
The mean age of all patients was 44.98 years and showed a statistically significant difference between the 2 groups (44.35 [SD, 7.92] y and 48.38 [SD, 8.59] y; P = 0.001). There was also a statistically significant difference in the case of diabetes (9 [3.54%] and 8 [17.02%]; P = 0.002), hypertension (25 [9.84%] and 10 [21.28%]; P = 0.043), neoadjuvant chemotherapy status (15 [7.14%] and 11 [25%]; P = 0.001), and BMI. Patients in the ICG group had a higher BMI (P < 0.001). Only 30% of patients had previous abdominal surgery. Most patients were treated with surgery with a diagnosis of breast cancer (94.68%), and most of them had early-stage breast cancer (stage 0–II, 74.89%). In all, 71% and 58% of cancers were hormonal receptor positive: estrogen and progesterone receptor, respectively.
Details of the operation are shown in Table 2. As the primary outcome, the total flap complication rate was 22.9% (69 of 301 patients). In the non-ICG group, we observed a total of 61 patients with complications, of which 40 had mild fat necrosis, 19 had severe fat necrosis, 1 had partial flap necrosis, and 1 had complete flap loss. In the ICG group, we observed 8 patients with complications, of which 4 had mild fat necrosis and 4 had severe fat necrosis. No flap loss was found in this group. No statistical significance was found between the 2 groups. The median duration between post–radiation therapy (RT) and delayed TRAM flap reconstruction was 23.5 months (percentile 25, percentile 75: 18.75, 26.25 months). Flap complications were diagnosed through both PE and radiological investigation. Without positive PE, we found mild fat necrosis from radiological findings, U/S with MMG, and CT scan, about 20 (29%) patients. However, no further surgical management was needed in this group.
Table 2.
Operation and Outcomes
| Total (N = 301) | Non-ICG (N = 254) | ICG (N = 47) | P | |
|---|---|---|---|---|
| Breast operation, n (%) | <0.001 | |||
| Skin-sparing mastectomy | 112 (37.21) | 93 (36.61) | 19 (40.43) | 0.619 |
| NSM | 35 (11.63) | 20 (7.87) | 15 (31.91) | <0.001 |
| Total mastectomy | 132 (43.85) | 124 (48.82) | 8 (17.02) | <0.001 |
| Delay reconstruction | 22 (7.31) | 17 (6.69) | 5 (10.64) | 0.359 |
| Operative time, median (p25, p75), min | 225 (185, 252.5) | 210 (180, 250) | 310 (265, 365) | <0.001 |
| Total flap complication, n (%) | 69 (22.92) | 61 (24.01) | 8 (17.02) | 0.556 |
| Type of flap complication, n (%) | ||||
| Mild fat necrosis | 44 (63.77) | 40 (65.57) | 4 (50) | 0.197 |
| Severe fat necrosis | 23 (33.33) | 19 (31.15) | 4 (50) | 0.767 |
| Partial flap loss | 1 (1.45) | 1 (1.64) | 0 | 0.999 |
| Complete flap loss | 1 (1.45) | 1 (1.64) | 0 | 0.999 |
| By diagnostic tool, n (%) | ||||
| PE | 49 (71.01) | 43 (70.49) | 6 (75) | |
| U/S and MMG | 17 (24.64) | 15 (24.59) | 2 (25) | |
| CT | 3 (4.35) | 3 (4.92) | 0 | |
| Preserve partial zone 4, n (%) | 8 (2.66) | 0 (0) | 8 (17.02) | <0.001 |
| Reoperation, n (%) | 8 (2.66) | 7 (2.76) | 1 (2.13) | 0.999 |
| Donor complication, n (%) | ||||
| Seroma | 11 (3.65) | 10 (3.94) | 1 (2.13) | 0.999 |
| Wound dehiscence | 10 (3.32) | 6 (2.36) | 4 (8.51) | 0.054 |
| Surgical site infection | 27 (8.97) | 20 (7.87) | 7 (14.89) | 0.159 |
| Umbilical hernia | 7 (2.33) | 5 (1.97) | 2 (4.26) | 0.300 |
| Other | 2 (0.66) | 0 | 2 (4.26) | 0.024 |
For secondary outcomes, there were differences in the type of operation. We found a statistically significant difference between the 2 groups. Total mastectomy was found more in the non-ICG group than in the ICG group (124 [48.82%] and 8 [17.2%], respectively). In contrast, the other type of operation was found more in the ICG group (P < 0.001). There were also differences in median operative time (210 and 310 min, respectively; P < 0.001). For donor-site complications—seroma, wound dehiscence, surgical site infection, umbilical necrosis—no statistically significant difference had been found between both groups. Reoperation after breast reconstruction due to flap complications was recorded in 8 patients in total. By using fluorescence guidance rather than relying solely on anatomy, flap tissue was preserved in a more extensive partial zone IV area in 8 patients (17%) (P < 0.001).
We compared outcomes between patients with or without flap complications (Table 3). Higher BMI and postoperative RT were significantly associated with flap complications. The type of operation, previous abdominal incision, and diabetics, which we reviewed in the literature and found to be associated with fat necrosis, were not significantly associated with higher flap complications in this study. The effect of maintaining a partial zone IV on flap complications was not significant (P = 0.477). Using intraoperative ICG fluorescence was also not associated with flap complication rates.
Table 3.
Comparison Between Patients With and Without Flap Complications
| Total (N = 301) | No Flap Complication (N = 232) | Flap Complication (N = 69) | P | |
|---|---|---|---|---|
| Age, mean (SD), y | 44.98 (8.14) | 44.95 (7.80) | 45.08 (9.25) | 0.907 |
| BMI, kg/m2, n (%) | ||||
| <25 (normal) | 211 (70.10) | 173 (74.57) | 38 (55.07) | 0.002 |
| 25–30 (overweight) | 77 (25.58) | 52 (22.41) | 25 (36.23) | 0.027 |
| >30 (obesity) | 13 (4.32) | 7 (3.02) | 6 (8.70) | 0.083 |
| Diabetes mellitus, n (%) | 17 (5.65) | 14 (6.03) | 3 (4.35) | 0.771 |
| Hypertension, n (%) | 35 (11.63) | 25 (10.78) | 10 (14.49) | 0.397 |
| Smoking, n (%) | 3 (1) | 2 (0.86) | 1 (1.45) | 0.543 |
| Previous incision, n (%) | ||||
| Low transverse | 55 (18.27) | 45 (19.40) | 10 (14.49) | 0.478 |
| Low midline | 20 (6.64) | 16 (6.90) | 4 (5.80) | 0.999 |
| Periumbilical | 5 (1.66) | 5 (2.16) | 0 | 0.592 |
| RLQ (McBurney) | 12 (3.99) | 7 (3.02) | 5 (7.25) | 0.154 |
| Primary tumor, n (%) | ||||
| Unilateral breast cancer | 285 (94.68) | 220 (94.83) | 65 (94.20) | 0.082 |
| Bilateral breast cancer | 2 (0.66) | 0 | 2 (2.90) | |
| Phyllode | 10 (3.32) | 9 (3.88) | 1 (1.45) | |
| Benign | 4 (1.33) | 3 (1.29) | 1 (1.45) | |
| Chemotherapy, n (%) | ||||
| Neoadjuvant | 26 (10.24) | 20 (10.26) | 6 (10.17) | 0.985 |
| Adjuvant | 182 (71.65) | 136 (69.74) | 46 (77.97) | 0.219 |
| RT, n (%) | ||||
| Preoperative | 8 (3.11) | 5 (2.55) | 3 (4.92) | 0.399 |
| Postoperative | 79 (31.10) | 52 (26.67) | 27 (45.76) | 0.005 |
| Breast operation, n (%) | ||||
| Skin-sparing mastectomy | 112 (37.21) | 86 (37.07) | 26 (37.68) | 0.661 |
| NSM | 35 (11.63) | 25 (10.78) | 10 (14.49) | |
| Total mastectomy | 132 (43.85) | 102 (43.97) | 30 (43.48) | |
| Delay reconstruction | 22 (7.31) | 19 (8.19) | 3 (4.35) | |
| Operative time, median (p25, p75), min | 225 (185, 282.5) | 225 (180, 285) | 230 (195, 280) | 0.359 |
| Using ICG guidance, n (%) | 47 (15.61) | 39 (16.81) | 8 (11.59) | 0.349 |
| Preserve partial zone 4, n (%) | 8 (2.66) | 7 (3.02) | 1 (1.45) | 0.477 |
RLQ, right lower quadrant area of abdomen.
We studied factors related to flap complications (Table 4). Flap complications were significantly associated with high BMI (>25 kg/m2) (odds ratio [OR] = 2.18, P = 0.010, and OR = 3.90, P = 0.020 for BMI 25–30 kg/m2 and BMI >30 kg/m2, respectively). Postoperative RT was also associated with flap complications (OR = 2.32, P = 0.006). Other factors, such as diabetes, smoking, previous surgical incision, preoperative RT, and ICG usage, were not related to flap complications after pedicled TRAM flap reconstruction.
Table 4.
Factors Related to Flap Complications
| OR | 95% CI | P | |
|---|---|---|---|
| BMI, kg/m2 | |||
| <25 (normal) | Ref | Ref | Ref |
| 25–30 (overweight) | 2.18 | 1.21–3.95 | 0.010 |
| >30 (obesity) | 3.90 | 1.24–12.26 | 0.020 |
| Diabetes mellitus | 0.70 | 0.19–2.53 | 0.596 |
| Smoke | 1.69 | 0.15–18.93 | 0.670 |
| Previous incision | |||
| Low transverse | 0.70 | 0.33–1.48 | 0.357 |
| Low midline | 0.83 | 0.26–2.57 | 0.748 |
| Periumbilical | Omitted | ||
| RLQ (McBurney) | 2.51 | 0.77–8.17 | 0.126 |
| RT | |||
| Preoperative | 1.97 | 0.45–8.51 | 0.361 |
| Postoperative | 2.32 | 1.27–4.23 | 0.006 |
| Using ICG guidance | 0.649 | 0.28–1.46 | 0.298 |
CI, confidence interval; Ref, reference; RLQ, right lower quadrant area of abdomen.
DISCUSSION
Hartrampf classification5,6 was first described to divide the skin of pedicled TRAM flap breast reconstruction into 4 zones according to their vascularization. According to the standard procedure, we split the lower abdominal flap in the middle to form 2 hemiabdomens and divide each site equally, resulting in 4 zones. We remove zone IV of the TRAM flap intraoperatively due to insufficient perfusion from the vascular supply. The vasculature is one of the various variations in the anatomy of the human body. We use residual tissues from zones I–III for reconstruction, and if there is a major defect on the chest wall, surgeons may require more tissues for reconstruction to improve the shape and contour of the reconstructed breast. Zones II and III’s blood supply is unpredictable and, depending only on classification, could result in issues such as flap loss, skin necrosis, or fat necrosis, which occasionally require reparations.
Smit et al10 in a meta-analysis included 64 articles and reported that the use of fluorescence imaging led to significantly increased flap survival. The reasons for these improvements were earlier recognition of a decreased perfusion and, thereby, faster surgical intervention or excision of poorly perfused areas, a change of the entire surgical plan by converting to a different free flap or by including additional perforators, and a shortened time to identify anatomy.10
ICG is a water-soluble dye that emits infrared energy within 2 minutes of injection. ICG has previously been used for cardiac output measurement, hepatic function evaluation, and ophthalmic angiography, with few related adverse reactions.13 The ICG measurement was demonstrated to represent a safe, quick, and accurate technique of flap perfusion analysis.7,13 A study conducted by Chirappapha et al9 from our institute found that although the outcome of the ICG fluorescence imaging technique is not significantly different from an anatomy-based surgical technique in pedicled TRAM flap reconstruction in previous studies, it is still a helpful tool in identifying the flap transaction border, especially in complex cases such as those with low midline scars or when a large area of flap coverage is required. There was no reoperative procedure in any of the 29 patients, and after a follow-up of 6 months, 4 (13.33%) cases of fat necrosis were reported via an ultrasonographic examination.
This retrospective study examined the use of intraoperative ICG versus nonuse of intraoperative ICG during unilateral pedicled TRAM flap repair. Very few patients in our series had comorbidities or smoking history (Table 1). Compared with patients in non-ICG groups, patients in ICG groups tended to have more cases of NSM and skin-sparing mastectomy for the type of operation (Table 2). We officially applied ICG for a flap evaluation around 2013 in our department, so most data in the ICG group were included in the latter half of the study. NSM was not widely used in our institute in the past due to oncological concerns, so it may explain why procedures and operating times were different. This study’s overall flap complication rate of 22.9% is significantly greater than the literature’s reported rates of fat necrosis in traditional pedicled TRAM flap procedures (14%–21%).3,9,11
Our study included fat necrosis in a patient who was negative for PE but was diagnosed by radiological investigation, U/S with MMG, and CT scan, which gave us the ability to detect more mild fat necrosis after breast reconstruction than past literature where radiological findings were not included.3,6,7,12,14 We only found mild fat necrosis in 3 of 80 (3.75%) patients who underwent postoperative CT scans for follow-up. However, in all 20 patients whose flap complications were diagnosed by radiological investigation, U/S with MMG, and CT scan, no further surgical management was required and the complications did not affect the cosmetic aspect of breast reconstruction. We think that advanced radiological investigation, such as a CT scan, can give surgeons a more precise evaluation of breast reconstruction outcome and reveal complications that may not be detectable from PE. Nonetheless, these findings generally do not alter subsequent management or require reoperation, though they may assist in improving cosmetic outcomes. Then, PE and standard radiological surveillance for cancer will be sufficient and appropriate for practical treatment.
We also compared patient outcomes with or without flap complications (Table 3). Mostly, there was no association with flap complications except BMI and postoperative RT. Hence, we used logistic regression analysis to find any factor that affects flap complications. From our literature review, several factors were found to be related to flap complications in previous studies. Risk factors related to flap complications identified in this study included high BMI (BMI >25 kg/m2) and adjuvant postoperative RT (Table 4). The same result, that higher BMI was significant, was also found in previous studies.3,15,16 Previous literature has also reported varying results regarding the impact of RT on flap complications.3,11,15,17,18 There are many mechanisms that explain the effect of RT on flap complications. Radiation can affect the function of endothelial cells, causing changes in vascular biology and damage to vascular function, leading to an inflammatory reaction and the formation of microvascular thrombosis. This mechanism is the process of a series of flap complications caused by radiotherapy. These complications include infection, hematoma, fistula, wound dehiscence, vessel thrombosis, and flap necrosis.18,19 For preoperative RT, there were few patients in our study. Previous abdominal incisions, such as lower transverse, lower midline, right lower quadrant area of abdomen (McBurney), or periumbilical incisions, were not related to flap complications, a result similar to that seen in previous reports.3,20
Smoking was not a significant factor, but our series had fewer patients. Using fluorescence imaging, ICG also showed no significant association with flap complications.
In oncoplastic surgery and breast reconstruction, fat and skin necrosis are 2 common complications, and sometimes they affect the cosmetic outcome of breast reconstruction. ICG usage is still not beneficial compared with conventional TRAM flap reconstruction surgery. However, even though not statistically significant, the present study shows a reduction in the rate of total flap complications, both fat necrosis and flap necrosis, of approximately 7% (from 24.01% in the non-ICG group to 17.02% in the ICG group) and no severe flap complications, partial flap loss, or complete flap loss in the ICG group. The ICG fluorescence guidance during reconstruction provides more opportunities to preserve flap tissue, especially in zone IV. This delivers greater flexibility and possibilities for using a wider range of tissue. We think that if the use of ICG is limited, it should be applied in patients with risk factors associated with flap complications: high BMI and adjuvant radiation.
Although there is a comparison between groups, the limitation of this study is that it is a retrospective study, which may cause confounding biases due to a lack of information on confounding factors not available in the medical records. Another factor is the dose and duration of fluorescence observed from ICG. Because there is still no standardized dose and duration for ICG usage, we may need more evidence and standards of ICG usage. Further prospective, randomized studies are needed to confirm the efficacy and application of ICG in determining pedicled TRAM flaps.
CONCLUSIONS
The ICG fluorescence imaging technique is not significantly different from an anatomy-based surgical technique in pedicled TRAM flap reconstruction regarding postoperative flap complications. However, it still helps surgeons to identify insufficient perfusion areas, preserve more of the skin flap, and improve decision-making, which leads to a lower incidence of flap complications. High BMI and postoperative RT are related to flap complications.
DISCLOSURE
The authors have no financial interest to declare in relation to the content of this article.
PATIENT CONSENT
Written informed consent was obtained from all patients.
ACKNOWLEDGMENT
The authors acknowledge Ms. Pattawia Choikrua for help with the statistical analysis.
ETHICAL APPROVAL
This study was approved by the ethics board of the Committee on Human Rights Related to Research Involving Human Subjects, Faculty of Medicine Ramathibodi Hospital, Mahidol University, based on the Declaration of Helsinki (MURA2024/361).
Footnotes
Published online 26 September 2025.
Disclosure statements are at the end of this article, following the correspondence information.
REFERENCES
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