Dros yr 20 mlynedd diwethaf mae gwasanaethau fasgwlaidd wedi newid yn sylweddol. Mae'r angen am driniaethau arbenigol a chymhleth wedi arwain at gasglu adnoddau ac arbenigedd mewn llai o leoliadau. Mae nifer o fanteision i hyn – mae rheoli cyflyrau'n dda yn hanfodol i gyflawni'r canlyniadau gorau i gleifion a sicrhau GIG sy'n gynaliadwy. Fodd bynnag, mae gwasanaethau mewn rhai ardaloedd o Gymru wedi wynebu heriau sylweddol, yn bennaf Bwrdd Iechyd Prifysgol Betsi Cadwaladr, lle mae gwaith gwella dwys wedi bod yn mynd rhagddo mewn ymateb i nifer o adolygiadau.
Over the last 20 years vascular services have changed significantly, and the need for specialised and complex procedures has led to a concentration of resources and expertise at fewer locations. This has a number of benefits - well managed conditions are vital to delivering the best patient outcomes and delivering a sustainable NHS. However, there have also been significant service challenges in some parts of Wales, most notably at the Betsi Cadwaladr University Health Board where concerted improvement work has been underway in response to a number of reviews.