Acute lower extremity arterial thrombosis after intraocular foreign body removal under general anesthesia: A case report and review of literature

BACKGROUND Surgery,which is a major risk factor for venous thrombosis,has rarely been considered a risk factor for arterial thrombosis.Recent studies have suggested that venous and arterial thromboses share common risk factors and have a bidirectional relationship.Accordingly,there is a growing interest in the risk of arterial thrombosis after surgery.We report a case of acute bilateral lower extremity arterial thromboses that developed after a prolonged surgery.CASE SUMMARY A 59-year-old man was hospitalized for intraocular foreign body removal surgery.He was a heavy-drinking smoker and had untreated hypertension and varicose veins in both legs.The operation was unexpectedly prolonged,lasting 4 h and 45 min.Immediately after emergence from general anesthesia,the patient complained of extreme pain in both legs.After the surgical drape was removed,cyanosis was evident in both feet of the patient.The pulse was not palpable,and continuous-wave Doppler signals were inaudible in the bilateral dorsalis pedis and posterior tibial arteries.Computed tomography angiography confirmed acute bilateral thrombotic occlusion of the popliteal arteries,proximal anterior tibial arteries,and tibioperoneal trunks.Arterial pulse returned in both lower limbs after 6 h of heparin initiation.The patient was discharged on postoperative day 26 without any sequelae.CONCLUSION Acute lower extremity arterial thrombosis can occur after surgery.Anesthesiologists should pay particular attention to patients with risk factors for thrombosis.

Graphene-based saturable absorber and mode-locked laser behaviors under gamma-ray radiation

We investigate optical and electrical behaviors of a graphene saturable absorber (SA) and mode-locking performance of a graphene-SA-based mode-locked Er fiber laser in gamma-ray radiation. When irradiated up to 4.8 kGy at ~ 100 Gy/hr dose rate, the overall nonlinear transmittance in transverse electric mode was increased, while maintaining modulation depth to >10%. The corresponding polarization.dependent loss was reduced at a 1.2-dB/kGy rate. In the electrical properties, the charge carrier mobility was reduced, and the Dirac voltage shift was increased to positive under gamma-ray radiation. The radiation-induced optical and electrical changes turned out to be almost recovered after a few days. In addition, we confirmed that the graphene-SA-based laser showed stable CW mode-locking operation while the inserted graphene SA was irradiated for 2-kGy at a 45-Gy/hr dose rate, which corresponds to >40 years of operation in low Earth orbit satellites.To the best of our knowledge, this is the first evaluation of graphene SAs and graphene-SA-based mode-locked lasers in gamma-ray radiation, and the measured results confirm the high potential of graphene SAs and graphene-SA-based lasers in various outer-space environments as well as other radiation environments, including particle accelerators and radiationbased medical instruments.