The present disclosure pertains to membranous tissue grafts comprising one or more pre-made attachment points. The one or more pre-made attachment points may include pre-made markings and/or pre-made suture holes. The membranous tissue grafts can be in the form of a tube. The membranous tissue grafts can also be rectangular in shape and can be used in a nerve repair by wrapping the severed or damaged nerve. In some embodiments, the membranous tissue grafts are suitable for repairing severed nerves that have a short gap or no gap with a gap of less than 5 mm between the severed stumps. Accordingly, methods are provided for repairing a damaged or severed nerve by implanting the membranous tissue grafts on to the damaged or severed nerve.