TABLE 3.
A table showing the characteristics and results of studies included in the review
| Study code | Study | Study location | Study design (study population [n]) | Study modality | Definition of artery hypoplasia | Distinct variants (n) | Quality assessment score (n/25) |
|---|---|---|---|---|---|---|---|
| S1 | Al‐Hussain et al. (2001) | Jordan | CSS (50) | CD | <1 mm | 4 | 11 |
| S2 | Benson et al. (1986) | Canada | CR (1) | CD | N/A | 1 | N/A |
| S3 | Cilliers et al. (2018) | South Africa | CSS (59) | CD | <1 mm | 10 | 15 |
| S4 | De Silva et al. (2011) | Sri Lanka | CSS (225) | CD | <1 mm | 15 | 18 |
| S5 | Ding et al. (2019) | China | CR (1) | CD | N/A | 1 | N/A |
| S6 | Drummond et al. (2006) | USA | CR (1) | TOF MRA | N/A | 1 | N/A |
| S7 | Drummond et al. (2012) | USA | CR (1) | TOF MRA | N/A | 1 | N/A |
| S8 | Eftekhar et al. (2006) | Iran | CSS (102) a | CD | <1 mm | 10 | 15 |
| S9 | Giglio et al. (2010) | Italy | CR (1) | MRA | N/A | 1 | N/A |
| S10 | Gurdal et al. (2004) | Turkey | CR (2) | CD | N/A | 2 | N/A |
| S11 | Hafez et al. (2007) | Egypt | CSS (130) | 3D TOF MRA and CD | <1 mm | 7 | 11 |
| S12 | Hashemi et al. (2013) | Iran | CSS (200) | CD | <1 mm | 9 | 12 |
| S13 | He et al. (2016) | China | PCS (102) | CTA | <1 mm | 1 | 15 |
| S14 | Howe (1903) | USA | CR (1) | CD | N/A | 1 | N/A |
| S15 | Howie (1959) | USA | CCS (256) | CD | N/A | 10 | 4 |
| S16 | Ibrahim et al. (2017) | Sudan | CCS (146) | 3D TOF MRA | N/A | 5 | 10 |
| S17 | Iqbal (2013) | India | CSS (50) | CD | <1 mm (AComA and PComA <0.5 mm) | 5 | 13 |
| S18 | Jensen et al. (2017) | USA | CR (1) | DSA | N/A | 1 | N/A |
| S19 | Karatas et al. (2016) | Turkey | CSS (100) | CD | N/A | 2 | 14 |
| S20 | Klimek‐Piotrowska et al. (2013) | Poland | CSS (250) | CTA | N/A | 3 | 14 |
| S21 | Klimek‐Piotrowska et al. (2015) | Poland | CSS (100) | CD | <1 mm | 30 | 17 |
| S22 | Li et al. (2020) | China | CSS (819) | 3D TOF MRA and DSA | <1 mm | 7 | 16 |
| S23 | Loh and Sharma (2010) | Singapore | CR (1) | TOF MRA | N/A | 1 | N/A |
| S24 | Malamateniou et al. (2009) | UK | CSS (103) | 3D TOF MRA | N/A | 3 | 18 |
| S25 | Manninen et al. (2009) | Finland | CSS (92) | Cerebral cast angiography | N/A | 1 | 19 |
| S26 | Matsuda et al. (2017) | Japan | CR (1) | MRA | N/A | 1 | N/A |
| S27 | McCullough (1962) | USA | CS (77) | CD | N/A | 4 | N/A |
| S28 | Ozturk et al. (2008) | Turkey | CR (1) | CD | N/A | 1 | N/A |
| S29 | Papantchev et al. (2007) | Bulgaria | CSS (112) | CD | <1 mm | 3 | 12 |
| S30 | Papantchev et al. (2013) | Bulgaria | CSS (500) | CD and CTA | <1 mm | 6 | 16 |
| S31 | Riggs and Rupp (1963) | USA | CSS (994) | CD | N/A | 20 | 7 |
| S32 | Sabau et al. (2012) | Romania | CR (1) | 3D TOF MRA | N/A | 1 | N/A |
| S33 | Saikia et al. (2014) | India | CSS (70) | TOF MRA | <1 mm | 2 | 14 |
| S34 | Saphir (1935) | USA | CR (3) | CD | N/A | 3 | N/A |
| S35 | Sonobe et al. (2019) | Japan | CR (1) | MRA | N/A | 1 | N/A |
| S36 | Sonobe et al. (2020) | Japan | CR (1) | MRA | N/A | 1 | N/A |
| S37 | Stefani et al. (2013) | Brazil | CSS (30) | MRA | N/A | 4 | 14 |
| S38 | Tripathi et al. (2003) | India | CR (1) | DSA | N/A | 1 | N/A |
| S39 | Uchino et al. (2015) | Japan | CR (2) | 3D TOF MRA | N/A | 2 | N/A |
| S40 | Urbanski et al. (2008) | Germany | PCS (99) | CTA | N/A | 4 | 12 |
| S41 | Vasović et al. (2010) | Serbia | CS (4) | CD | N/A | 2 | N/A |
| S42 | Vasović et al. (2013) | Serbia | CSS (333) | CD | <1 mm | 11 | 11 |
Abbreviations: CCS, case‐control study; CD, cadaveric dissection; CR, case report; CS, case series; CSS, cross‐sectional study; CTA, computed tomography angiography; DSA, digital subtraction angiography; ICoA, intermediate communicating artery; MRA, magnetic resonance angiography; N/A, not available; P1c, P1 segment of carotid origin; PCS, prospective cohort study; TOF, time‐of‐flight.
a
Results of only 92 out of 102 participants were recorded.