Direct inguinal hernia results from weakness of the posterior wall of the inguinal canal (Hesselbach's triangle), not from a patent processus vaginalis. Hence, simple herniotomy (sac ligation alone) is insufficient -- the posterior wall must be reinforced. Among the available options: Bassini's repair strengthens the posterior wall using a tension-based suture technique but carries a higher recurrence rate ($\sim 10-15\%$). Lichtenstein tension-free mesh hernioplasty places a polypropylene mesh over the posterior wall without suturing muscles under tension, achieving a recurrence rate of $<1\%$ and is therefore the current surgery of choice for direct inguinal hernia in adults. TEP (totally extraperitoneal) and TAPP (transabdominal preperitoneal) laparoscopic approaches are equally effective alternatives. \[\boxed{\text{Lichtenstein repair}}\]