Introduction
Background
Modalities for assessment of tissue perfusion
Method/Setting | use | Advantages | Limitations | Sources |
---|---|---|---|---|
Intraoperative
| ||||
ICG intraoperative laser angiography* | →Visualize perforator perfusion zone in real time | →Visualizes perforator perfusion zones | →Requires administration of contrast media | Phillips et al., 2012 [12] |
→Confirm patency of arterial and venous anastomoses | →No exposure to ionizing radiation | →Does not identify precise vessel location or course through muscle and fascia when lipodystrophy exists | Francisco et al., 2010 [52] | |
→Confirm perfusion of tissue prior to incision, after elevation of flaps, and prior to final closure | →Strong safety profile and short half-life of ICG | Komorowska-Timek & Gurtner, 2010 [1] | ||
→Permits re-evaluation during same surgery | Murray et al., 2010 [16] | |||
Tamburrino et al., 2010 [17] | ||||
Newman et al., 2009 [11] | ||||
Jones et al., 2009 [14] | ||||
Azuma et al., 2008 [18] | ||||
Prantl et al., 2008 [19] | ||||
De Lorenzi et al., 2005 [20] | ||||
Mothes et al., 2004 [8] | ||||
Holm, Tegeler, et al., 2002 [21] | ||||
Holm, Mayr, et al., 2002 [22] | ||||
Still et al. 1999 [23] | ||||
Doppler – handheld | →Identification of perforator vessel location | →Easy to use | →Provides information on discrete area below probe | Yu & Youssef, 2006 [29] |
→Widely available | →Requires direct skin contact | |||
→Inexpensive | →Does not identify perforator perfusion zone | |||
→Provides confirmatory information | →Provides limited data and accuracy for flap design, | |||
→especially in heavier patients | ||||
→Difficult to quantify | ||||
→Does not stratify perforators | ||||
Fluorescein | →Visualization of perforator perfusion zone | →Visualization of perforator perfusion zone | →Single use only | Phillips et al., 2012 [12] |
→Widely available | →No venous information | Losken et al., 2008 [51] | ||
→Long delay time | ||||
→Toxicity concerns | ||||
→Use of ultraviolet Woods lamp | ||||
→High sensitivity, low specificity | ||||
Preoperative
| ||||
Clinical judgment | →Estimation of tissue perfusion and flap viability | →Familiarity, ease of use | →Poor reliability when used alone | Phillips et al., 2012 [12] |
→Dependent on surgeon experience | Mothes et al., 2004 [8] | |||
→Inferior to imaging modalities for estimation of flap survival | Olivier et al., 2003 [9] | |||
Holm, Tegeler et al., 2002 [21] | ||||
Doppler Ultrasound (duplex, color, power) | →Identification of perforator vessel location | →No exposure to ionizing radiation or contrast media | →Inferior to CT angiography for identification of vessel location | Rozen et al., 2008 [24] |
→Estimate of vessel flow rate | →Provides estimation of perforator location, caliber, and flow | →Considered operator-dependent | Khalid et al., 2006 [25] | |
→Does not identify perforator perfusion zone | Giunta et al., 2000 [26] | |||
→High rate of false-positive findings reported | Hallock, 2003 [27] | |||
Blondeel et al., 1998 [28] | ||||
Laser Doppler flowmetry | →Identification of vessel location and tissue perfusion | →No exposure to ionizing radiation or contrast media | →May underestimate flap survival | Schlosser et al., 2010 [30] |
→Identifies ischemia in flaps | →Poor ability to detect perforator vessels | Holzle et al., 2006 [31] | ||
→Sensitive to small movements | Heller et al., 2001 [32] | |||
Heden et al.1986 [33] | ||||
CT angiography | →Visualization of location and course of vessels through muscles and fascia | →Accurate detection of anatomic location and course of vessels | →Does not assess vascular flow | Ghattaura et al.,2010 [34] |
→Greater accuracy than Doppler ultrasound | →Does not show perforator perfusion zones | Smit et al., 2009 [35] | ||
→Potential for reduced surgical time | →May have poor resolution for vessel caliber; | Rozen et al., 2008 [24] | ||
→Exposure to ionizing radiation | Cina et al., 2010 [36] | |||
→Potential toxicity of contrast media | Scott et al., 2010 [37] | |||
Phillips et al., 2008 [38] | ||||
Rosson et al., 2007 [39] | ||||
Masia et al., 2006 [40] | ||||
MR angiography | →Visualization of location and course of vessels through muscles and fascia | →Greater accuracy than Doppler ultrasound | →Does not assess vascular flow | Schaverien et al., 2011 [42] |
→Detection of small caliber vessels | →Does not show perforator perfusion zones | Newman et al., 2010 [43] | ||
→Potential for reduced surgical time | →Less spatial resolution compared to CT angiography | Greenspun et al., 2010 [45] | ||
→No exposure to ionizing | →Potential toxicity of contrast | Chernyak et al., 2009 [41] | ||
→radiation | →media | Neil-Dwyer et al., 2009 [44] | ||
Rozen et al., 2009 [46] | ||||
Postoperative
| ||||
Transcutaneous oxygen monitoring** | →Assessment of tissue oxygen saturation | →Useful for postoperative monitoring | →Limited to discrete 1 cm2 area under probe | Steele, 2011 [47] |
→Accurately detects vascular compromise | →Numeric output only | Lin et al., 2011 [48] | ||
→Improves flap salvage rate in postoperative setting | →Used primarily for postoperative monitoring | Keller, 2009 [49] | ||
→Time consuming, cumbersome for intraoperative mapping | Keller, 2007 [50] |
Evidence of utility for intraoperative Use of the SPY system
Use of SPY intraoperative perfusion assessment system in reconstructive surgeries
Authors | Study design | Applications studied | Key points |
---|---|---|---|
Free flaps
| |||
Pestana et al., 2009 [5] | Case series | Multiple indications: head and neck, breast, lower extremity | 1 partial flap loss |
N = 27 patients, 29 free tissue transfers | |||
Breast recon-struction
| |||
Phillips et al., 2012 [12] | Prospective study comparing ICG to fluorescein and clinical judgment | Tissue expander-implant breast reconstruction | ICG and fluorescein had sensitivity of 90% and specificity of 50% and 30%, respectively; negative predictive value for ICG and fluorescein was 88% and 82%, respectively. |
N = 32 patients, 51 breasts | |||
Newman et al., 2011 [6] | Case series | Breast reconstruction: single-pedicle TRAM | ICG perfusion assessment identified perfusion zones; no issues with wound healing or tissue or fat necrosis. |
N = 20 | |||
Komorowska-Timek and Gurtner, 2010 [1] | Case series | Breast reconstruction: tissue expander, latissimus dorsi flaps, DIEP/SIEA | Tissue expander (n = 16), latissimus dorsi (n = 2), DIEP/SIEA (n = 6); complication rate: 4% with ICG vs. 15.1% in 206 previous reconstructions (n = 148; p < 0.01) |
N = 20 patients, 24 breasts | |||
Tamburrino et al., 2010 [17] | Retrospective analysis | Breast reconstruction: tissue expander or unilateral TRAM | 95% correlation between ICG imaging and clinical outcome, 100% sensitivity and 91% specificity. |
Tissue expander (n = 11 patients, 19 breasts) | |||
Unilateral TRAM (n = 1) | |||
Francisco et al., 2010 [52] | Case series N = 5 | Breast reconstruction: DIEP | No flap loss, fat necrosis, or take-backs |
Jones et al., 2009 [14] | Case series | Breast reconstruction: free and pedicle TRAM, DIEP, latissimus dorsi, and expander insertions. | Of 5 patients with poor flap perfusion on ICG imaging, 4 developed necrosis and 1 blistering in a pattern predicted by ICG; necrosis rate of 6.3% vs. published rates of 15-25%. |
N = 43 patients, 64 breasts | |||
Newman & Samson, 2009 [11] | Case series | Breast reconstruction: DIEP or free TRAM | ICG detected marginal or poor perfusion in 4 cases; 3 were revised intraoperatively and the 1 that was not revised required return to OR for venous congestion. Flap survival was 100%. |
N = 8 patients, 10 breasts | |||
NAC evaluation
| |||
Murray et al., 2010 [16] | Case series | Breast reduction surgery | ICG used to demonstrate NAC perfusion and venous outflow during surgery. |
N = 12 patients, 22 breasts |
Recommendations for the intraoperative Use of SPY
Application | Points of use for ICG intraoperative laser angiography |
---|---|
Free flaps | 1. Identify perforator perfusion zone in donor site prior to incision; select optimal perforator and design flap |
2. Confirm flap perfusion during dissection, testing and comparing different perforators | |
3. Confirm flap perfusion after transfer | |
4. Confirm patency of arterial and venous anastomoses | |
5. Detect areas of venous congestion by re-imaging 5–20 min after administration of ICG; can be performed following flap dissection, transfer, and/or inset | |
Pedicle flap | 1. Identify perforator perfusion zone in donor site prior to incision; design flap |
2. Evaluate arterial and venous perfusion after elevation of flap and prior to transfer | |
3. After transfer and after inset, confirm arterial inflow and venous return | |
Skin flap | 1. Evaluate perfusion prior to incision; design flap |
2. After dissection, confirm flap perfusion | |
3. After transfer and inset, confirm perfusion of flap | |
Mastectomy flap | 1. Following mastectomy, confirm integrity of vascular perfusion in mastectomy flaps; select delayed vs. immediate reconstruction; select implant vs. expander reconstruction |
2. Confirm perfusion after insertion of reconstructive modality; determine expander volume or implant size; determine skin paddle size | |
3. If revisions made, confirm perfusion in flaps |
Application | Timing of evaluation* |
---|---|
Microvascular reconstructive surgery
| |
Pre-incision identification of perforators | 15-30 sec |
Following dissection, confirmation of adequate flow and limits of perfusion | 1-2 min |
Following transfer, evaluation of arterial and venous anastomoses | Arterial phase: instantaneous. |
Venous phase: 30–60 sec | |
Re-image at 2 min; if venous congestion is suspected, evaluate again at ≥4 min | |
Following inset, confirmation of adequate flow and limits of perfusion | 1-2 min (Wait at least 10 min following previous ICG administration) |
Pedicle flap reconstruction
| |
Pre-incision identification of perforator perfusion zone | ≤1 min |
Following elevation of flap, confirmation of adequate flow and limits of perfusion (selection of skin and soft tissue for preservation) | 1-2 min |
Following transposition and inset, confirmation of adequate flow and limits of perfusion | 1-2 min |
Skin flap reconstruction**
| |
Following elevation of skin flap, define limits of perfusion for flap design and detect sub-clinical ischemia | 1-2 min |
Following transposition and inset to confirm adequate perfusion | 1-2 min (Wait at least 10 min following previous ICG administration) |
Mastectomy followed by TE/I reconstruction
| |
Pre-mastectomy, map the vessels and the perfusion surrounding the nipple-areolar complex | 15-30 sec |
Following mastectomy, assess perfusion along the skin/tissue edges of the flap† Wait 30–45 minutes following completion of mastectomy procedure to ensure recovery of perfusion. If no fluorescence is detected after this time period, additional wait time of up to 30 minutes may be appropriate. | 3-4 min |
With implant or tissue expander in place, evaluate mastectomy skin flap prior to filling expander | Wait 5 min after insertion of implant or tissue expander before imaging |
After filling tissue expander, evaluate skin flaps, nipple-areolar complex, and surrounding tissue perfusion | Wait 5 min after filling tissue expander before imaging |
Mastectomy and other skin flaps | Mastectomy flaps |
Cervicofacial flaps | |
Facelift | |
Cheek flap | |
Cervical advancement flap | |
Forehead flap | |
Skin flap over pectoralis major | |
Degloving injuries, upper and lower extremity | |
Abdominal flaps (eg, hernia repair) | |
Component separation | |
Burn injuries | |
Local flaps and adjacent tissue transfers: | |
Bi-lobe flaps | |
Propeller flaps | |
Rhomboid flaps | |
Pedicle flaps | TRAM flap |
VRAM and extended VRAM flaps | |
Deltopectoral flap | |
Trapezius flap | |
Myocutaneous pectoralis flap | |
Latissimus dorsi flap | |
Submental flap | |
Supraclavicular artery flap | |
Lateral intercostal artery flap | |
Free flaps | TRAM flap |
DIEP flap | |
SIEA flap | |
ALT flap | |
Scapular/parascapular flaps | |
Submental flap | |
Fibular flap | |
DCIA flap | |
TUG/TMG flap | |
GAP flap | |
PAP flap | |
Breast reconstruction | Implant reconstructions |
Tissue expander reconstructions |
Free flaps
Pedicle flaps
Mastectomy flaps
Implant reconstruction
Skin-sparing and nipple-sparing procedures
Other skin flaps
Benefits in challenging morphologies
Amount and timing of ICG administration and coordination with image capture
Special considerations
Characteristics associated with ischemia | Previous radiation treatment |
Previous or aggressive surgery* | |
Current smoking | |
Obesity | |
Diabetes | |
Vasculopathy | |
Chronic corticosteroid use | |
Thin mastectomy flaps | |
Agents that interfere with imaging techniques | Methylene blue |
Lymphazurin blue | |
Agents that affect blood flow | Vasoconstrictors (eg, epinephrine)** |