Table 1. Summary of the included studies.
| Author (year) | Animal (model) | Number | LE induction | LE quantification/Lymph flow evaluation | Follow up (wks) | Surgical technique | Other treatment | Summary/outcome |
|---|---|---|---|---|---|---|---|---|
| Tilak and Howard [23] (1965) | Mongrel dogs (hind limb) | 4 | PLN. § | Lymphangiogram. Histological examination |
20 | ALNG | N/A | LNs were hard to examine. Unknown success rates. |
| Shesol et al., [24] (1979) | Lewis albino rats (hind limb) | 60 | PLN | Radioactive scan measuring lymph flow in popliteal region before and after intervention. | 1 | Lymphadenectomy Lymphadenectomy+ ipsilateral inguinal LN island flap. Lymphadenectomy+ LN free flap. Lymphadenectomy+ ALNG. Ipsilateral inguinal LN island flap without lymphadenectomy. |
N/A | 0/6 15/29 5/10 0/9 0/6 |
| Pabst et al., [55] (1988) | Gottingen minipigs | 6 | ILN or mesenteric lymohadenectomy. § | Histological examination | 24 | Fragmented ALNG to greater omentum. Fragmented ALNG to subcutaneous inguinal region. |
Killed Pasteurella multocida and Bordetella brochoseptica | No regeneration. Regeneration detected in all sections. |
| Chen et al., [52] (1990) | Dogs (hind limb) | 10 | Irradiation followed by skin stripping and PLN | Linear measurements, radionucleide scan, lymphangiography, histological examination. | 24 | VLNT of superficial inguinal LN + lymphatic anastomosis. VLNT of superficial inguinal LN without lymphatic anastomosis. |
N/A | Measurements: improvement after surgery, no difference between groups. Isotope study: improvement after surgery, no difference between groups. Histology: preserved size and architecture of transferred LNs in both groups (9/10). |
| Tammela et al., [50] (2007) | Mouse (upper limb) | 20 | Axillary lymphadenectomy. | Fluorescent dextran micro-lymphangiography. | 8 | LN allograft LN allograft + VEGF-C |
VEGF-C | Dextran detected in 22% (2/9) of mice. Dextran detected in 82% (9/11) of mice. |
| Tobbia et al., [58] (2009) | Dorset sheep (hind limb) | 50 | PLN. § | Transport rate of iodine 125 HSA to blood (%injected/hr) | 12 | VLNT ALNG Sham control |
N/A | 15.7 ± 1.0 percent /hour 12.6 ± 0.8 percent /hour 16.1± 0.7 percent / hour VLNT are superior to ALNG. |
| Hadamitzky et al., [42] (2009) | Lewis rat | 44 | Bilateral ILN. § |
Proportion of regenerated LNs (%) by histological examination. | 4 | Whole ALNG Fragmented ALNG Fragmented ALNG+ sheep RBCs Fragmented ALNG+ PRP Control |
PRP, Sheep RBCs. |
81.8% 63.6% 50% 100% 0% |
| Blum et al., [54] (2010) | Gottingen minipigs | 26 | ILN. § |
Tc-99 m-NC-SPECT/CT | 32 | Bilateral lymphadenectomy+ fragmented ALNG on one side. Bilateral lymphadenectomy+ fragmented ALNG on both sides |
Sheep RBCs | Impaired lymph flow and dermal back flow on the control side. Good lymph flow and less dermal backflow. |
| Lahteenvuo et al., [56] (2011) | Pigs | 19 | Damage to lymphatic vasculature around inguinal LNs. § |
Lymphangiography Histological examination. |
2 | ALNG+ VEGF-C ALNG+VEGF-D ALNG+ LacZ (control) |
VEGF-C VEGF-D |
↑ lymphatic growth ↑ lymphatic growth |
| Sommer et al., [41] (2012) | Lewis rats | 41 | ILN and PLN+ irradiation. § |
Proportion of regenerated LNs (%) by histological examination. | 4 | Fragmented ALNG Fragmented ALNG+ VEGF-C |
VEGF-C | 59% 74% |
| Uygur et al., [40] (2013) | Sprague-Dawley rats | 10 | N/A | laser-assisted ICG angiography. Histological examination. |
N/A | VLNT (a novel model of vascularized cervical LN flap) | N/A | Good perfusion of LN flap. Well-established vascular network. |
| Cheng et al., [39] (2014) | Sprague-Dawley rats | 18 | N/A | ICG fluorescence | N/A | VLNT Cutaneous flap devoid of LNs |
N/A | Dye detected. Dye not detected. |
| Schindewolff et al., [38] (2014) | Lewis rats (hind limb) | 109 | ILN and PLN. § |
Proportion of regenerated LNs (%) by histological examination. | 4 | Fragmented ALNG Fragmented ALNG+ saline Fragmented ALNG+ VEGF-C (abdominal wall) Fragmented ALNG+ VEGF-C (thigh) |
VEGF-C | 70% 70% 80% ≤85% |
| Kwiecien et al., [37] (2015) | Lewis rats | 10 | N/A | Histological examination | 1 | VLNT (a novel model of axillary LN flap to groin) | N/A | No signs of ischemia or necrosis. |
| Tervala et al., [49] (2015) | Immunodeficient nude mice (recepient) DsRed reporter mice (donor) |
50 25 |
Axillary lymphadenectomy. § | Proportion of surviving LNs by histological examination. | 12 | ALNG+ VEGF-C ALNG+ VEGF-D ALNG+ VEGF-C156S ALNG+ VEGF-A ALNG+ LacZ (control) |
VEGF-C, VEGF-D, VEGF-C156S, and VEGF-A | 8/10 8/10 6/9 1/6 0/10 |
| Suami et al., [51] (2016) | Mongrel dogs | 2 | Unilateral axillary and neck lymphadenectomy+ irradiation | Limb circumference Indocyanine lymphangiography |
56 | VLNT | N/A | Slight decrease. New lymphatic collaterals. VLNT may stimulate formation of new lymph vessels. |
| Visconti et al., [35] (2016) | Wistar rats | 15 | N/A | Methylene blue Histological examination |
4 | VLNT (a novel model of cervical lymph node-adipo-cutaneous flap to groin) | N/A | Restored lymph flow 100% of flaps viable. |
| Visconti et al., [36] (2016) | Wistar rats | 8 | ILN. § | Methylene blue Histological examination |
6 1/2 | VLNT ( a novel model of cervical venous LN flap) | N/A | Patent anastomosis. ↓↓stromal compartment, preserved sinus. |
| Shioya et al., [48] (2016) | Mice (hind limb) | 8 | Subiliac and PLN+ irradiation | Paw volume Indocyanine fluorescent |
8 | ALNG Control |
N/A | ↓paw volume, functional LN with collateral pathway. ↑paw volume, dermal backflow pattern. |
| Huang et al., [47] (2016) | FLT-4 DTR mouse (hind limb) | NR | subdermal hindlimb diphtheria toxin injections+ PLN. | Hind limb thickness | 15 | ALNG Sham surgery (control) |
N/A | 4.8%↑ 31.1%↑ |
| Ito et al., [34] (2016) | Sprague-Dawley rats | 18 | N/A | ICG fluorescence | N/A | LN containing groin flap LN devoid DIEP flap |
N/A | ICG detected in pedicle vein in 58.3% 0.0% |
| Nguyen et al., [33] (2016) | Sprague-Dawley rats (hind limb) | 18 | ILN and PLN+ irradiation | Volumetric analysis using micro-CT imaging | 12 | Single VLNT Three VLNT No VLNT (control) |
N/A | -8.9% ± 5.2% -9.1% ± 3.1% 7.6% ± 3.3% |
| Hayashida et al., [46] (2017) | C57BL/6J mice (hind limb) | 20 | PLN+ irradiation | Paw volume | 2 | VLNT VLNT+ADSC Skin flap Skin flap+ ADSC |
ADSC | 0.284 to 0.453 0.241 to 0.265 0.294 to 0.480 0.312 to 0.438 |
| Aydogdu et al., [32] (2017) | Sprague-Dawley rats | 30 | PLN | Limb measurement | 12 | VLNT Control |
N/A | ↓↓ |
| Najjar et al., [31] (2018) | Sprague- Dawley rats | 7 | ILN | ICG fluorescence Uptake by LN. |
37 | VLNT | N/A | ICG uptake by LN in 5/7 |
| Kwiecien et al., [30] (2018) | Sprague-Dawley rats | 14 | N/A | Time to ICG fluorescence detection in axillary vein (in seconds) | N/A | Control (no VLNT) 2 VLNT 4 VLNT |
N/A | 229s 79s 56s |
| Maeda et al., [45] (2018) | C57BL/6N mice | 36 | PLN | ICG fluorescence to detect whether lymph directed to inguinal LNs. | 4 | ALNG Control (no ALNG) |
N/A | 2/18 8/18 |
| Yang et al., [29] (2018) | Sprague- Dawley rats | 12 | N/A | ICG uptake, laser doppler, histological examination to evaluate effect of ischemia on LNs | N/A | Clamping of vascular pedicle of groin LN flap for 0,1,2,3,4,5,6,7 hours. | N/A | The critical ischemia time for vascularized LNs is 5 hours in the tested animal model. |
| Hadamitzky et al., [53] (2018) | Gottinger Minipig |
8 | Right groin lymphadenectomy | SPECT-CT, histological examination to assess LN regeneration rate (%) | 24 | LN resection and immediate replantation (ALNG) LN resection and implantation after cryopreservation for 1 mo |
N/A | 75% 67% |
| Penuela et al., [57] (2019) | New Zealand White rabbit (hind limb) | 8 | PLN | Hind limb volume. | 4 | VLNT | N/A | Basal: (51.94 ± 11.23) Transfer day: (73.40 ± 26.47) Final: (50.13 ± 12) |
| Ishikawa et al., [44] (2019) | Mouse | 25 | PLN. § | ICG lymphography | 4 | VLNT (a novel model of inguinal LN bearing flap containing superficial caudal epigastric vessels) | N/A | Reconnection of LN with afferent lymphatics in 16/25 |
| Ishikawa et al., [43] (2019) | C57BL/6 N mice | 50 | PLN. § | Afferent lymphatic reconnection by histological examination. | 4 | pedicled vascularized LNT pedicled nonvascularized LNT ALNG |
N/A | 13/20 11/15 7/15 |
| Perrault et al., [28] (2020) | Prox1-EGFP reporter rats | 48 | N/A | histological examination to evaluate effect of ischemia and reperfusion on LNs | 5 days | LN containing groin flaps subjected to ischemia for either 1, 2, 4, or 8 hours and harvested after 0 hours, 24 hours, and 5 days. | N/A | Critical time for ischemia: 4 hrs. Critical time for reperfusion injury:2hrs |
| Tinhofer et al., [27] (2020) | Lewis rats | 27 | N/A | laser doppler, histological examination. | N/A | Groin LN flap+ clamping of femoral artery and vein for 1,3,4 or 5 hours. | N/A | Critical venous occlusion time: 4 hrs. |
| Frueh et al., [26] (2020) | Lewis rats | 44 | N/A | Western blot and histological examination. | N/A | Vascular LN flaps+ ischemia for 45 or 120 mins+ reperfusion for 24 hrs VLNT (control) |
N/A | Ischemia for 120 mins lead to marked ↓ in cellularity compared to control. |
LE: Lymphedema, ALNG: Avascular lymph node graft, LN: Lymph node, PLN: Popliteal lymphadenectomy, §: Model of acute lymphatic damage without lymphedema, ILN: Inguinal lymphadenectomy, VEGF: Vascular endothelial growth factor, VLNT: Vascular lymph node transfer, CT: Computed tomography, ICG: Indocyanine green, ADSC: Adipose-derived stem cells, PRP: Platelet-rich plasma, LNT: Lymph node transfer