Delayed Management of Popliteal Artery Injury Following Knee Dislocation—A Case Report

Knee dislocations frequently involve vascular injuries that demand early diagnosis and timely intervention. Time of ischemia is pivotal in determining the outcome for the limb, delays in treatment beyond 8 hours significantly increase the risk of limb loss. Unfortunately, this critical window is often missed in resource-limited settings. Here we report a 25-year-old female sustained a left knee injury after falling into a trench. She was diagnosed with an open knee dislocation accompanied by a popliteal artery injury. However, revascularization was delayed for 18 hours due to limited resources, including the unavailability of a thrombectomy catheter. Postoperatively, the patient received anticoagulation therapy with serial limb assessments and after 3 weeks the laceration healed and the limb was still viable. Knee dislocations frequently result in vascular injury (popliteal artery most common), making prompt diagnosis and intervention essential for limb preservation. In settings with limited resources, like ours, delayed presentation and transfer to specialized centers contribute to prolonged ischemic times. Nonetheless, viable limbs should be revascularized in stable patients, even with prolonged ischemia. This case highlights the importance of limb revascularization despite delay. Efforts should be made to improve prompt diagnosis, timely referral, and availability of necessary equipment for vascular repair to optimize outcomes in similar cases.

Anesthetic management for the patients with cardiac transplant

With the advancement of medical technique and application of the new immunosuppressant agents, cardiac transplantation has become an effective treatment for end-stage heart disease caused by different reasons. The orthotopic procedure has been performed in many countries nowadays. Whether it is successful or not mainly depends on harvesting the denoted heart, operative technique and perioperative management.

Therapeutic imaging window of cerebral infarction revealed by multisequence magnetic resonance imaging An animal and clinical study

In this study, we established a Wistar rat model of right middle cerebral artery occlusion and observed pathological imaging changes （T2-weighted imaging [T2WI], T2FLAIR, and diffusion-weighted imaging [DWI]） following cerebral infarction. The pathological changes were divided into three phases： early cerebral infarction, middle cerebral infarction, and late cerebral infarction. In the early cerebral infarction phase （less than 2 hours post-infarction）, there was evidence of intracellular edema, which improved after reperfusion. This improvement was defined as the ischemic penumbra. In this phase, a high DWI signal and a low apparent diffusion coefficient were observed in the right basal ganglia region. By contrast, there were no abnormal T2WI and T2FLAIR signals. For the middle cerebral infarction phase （2-4 hours post-infarction）, a mixed edema was observed. After reperfusion, there was a mild improvement in cell edema, while the angioedema became more serious. A high DWI signal and a low apparent diffusion coefficient signal were observed, and some rats showed high T2WI and T2FLAIR signals. For the late cerebral infarction phase （4-6 hours post-infarction）, significant angioedema was visible in the infarction site. After reperfusion, there was a significant increase in angioedema, while there was evidence of hemorrhage and necrosis. A mixed signal was observed on DWI, while a high apparent diffusion coefficient signal, a high T2WI signal, and a high T2FLAIR signal were also observed. All 86 cerebral infarction patients were subjected to T2WI, T2FLAIR, and DWI. MRI results of clinic data similar to the early infarction phase of animal experiments were found in 51 patients, for which 10 patients （10/51） had an onset time greater than 6 hours. A total of 35 patients had MRI results similar to the middle and late infarction phase of animal experiments, of which eight patients （8/35） had an onset time less than 6 hours. These data suggest that defining the ＂therapeutic time window＂ as the time 6 hours after infarction may not be suitable for all patients. Integrated application of MRI sequences including T2WI, T2FLAIR, DW-MRI, and apparent diffusion coefficient mapping should be used to examine the ischemic penumbra, which may provide valuable information for identifying the ＂therapeutic time window＂.