Salvage of a failing microvascular free muscle flap by direct continuous intravascular infusion of heparin: a case report

A free gracilis muscle transfer with skin graft was performed for reconstruction of a type IIIB lower extremity traumatic wound with acute exposure of the distal tibia fracture site and an extensive soft-tissue wound. The free muscle flap failed from a venous thrombosis that was recognized 12 hours postoperatively, and reexploration revealed extensive venous thrombosis throughout the lower leg. The flap was salvaged by direct catheter administration of heparin into the vena comitans of the gracilis artery, which bathed the newly repaired venous anastomosis with an anticoagulating dose of heparin without systemic elevation of the patient's PTT. Ultimate full flap survival and wound healing ensued.     

老年患者PICC导管相关性上肢深静脉血栓治疗的影响因素

目的：研究老年患者PICC相关上肢深静脉血栓的治疗效果及影响因素。方法：选择我院西院233例行PICC置管后发生上肢深静脉血栓的老年患者,将其分为再通组及未再通组,收集患者的一般资料、基础疾病史、置管相关信息、血栓相关数据、是否拔除导管以及是否抗栓治疗等数据,并对结果进行统计分析。结果：126例上肢深静脉血栓患者中再通组拔除导管和接受抗栓治疗的比例明显高于不通组;拔除导管和接受抗栓治疗的患者其血栓完全再通的比例高于对照组。发现血栓后拔除导管组以及接受抗栓治疗组,其累积不通率要明显低于对照组。结论：PICC导管相关上肢深静脉血栓治疗中,拔除导管和接受抗栓治疗者其效果更优;出现PICC管相关性血栓的时候,对于导管仍有用途,没有感染迹象的老年患者,主张保留置管。     

Stent thrombosis in patients treated with thienopyridines: clinical description of 10 cases

Subacute stent thrombosis (SAST) is a major thrombotic complication of coronary stenting. Its occurrence has been substantially reduced by thienopyridine treatment. However, information on clinical profile of patients with SAST in clopidogrel era is limited. In order to define the incidence and factors predisposing to stent thrombosis, we analyzed the computerized angiographic database of three interventional cardiology centers. Out of a total number of 5903 percutaneous coronary interventions (PCIs) with stent implantation, we found 10 patients with SAST (0.17%). The indication for PCI was usually an early invasive approach (90%) during an acute coronary syndrome. All patients were treated with an apparently optimal antithrombotic regimen (90% received heparin or LMWH and 70% received IIb/IIIa receptor inhibitors and all given aspirin). In each of the patients, we could identify high-risk angiographic findings. SAST presentation was always clinically significant with definite myocardial infarction in 100% of cases. 80% of cases occurred during the first six days post PCI. Two patients had a recurrent event. Finally, despite earlier reports of atorvastatin-mediated inhibition of clopidogrel activation we did not find any patient with SAST taking both drugs. Thus, patients with stent thrombosis during thienopyridine treatment usually exhibit high-risk angiographic features. Prospective studies should be performed to elucidate drug interactions that may reduce clopidogrel efficacy and contribute to stent thrombosis.     

血清GPAA1、SF、OPN与儿童急性淋巴细胞白血病危险度的关系及对血栓发生风险的评估效能研究

摘要 目的：分析血清糖基磷脂酰肌醇锚附着蛋白1（GPAA1）、铁蛋白（SF）、骨桥蛋白（OPN）与儿童急性淋巴细胞白血病危险度的关系及对血栓发生风险的评估效能。方法：选择我院自2017年1月至2022年12月接诊的112例急性淋巴细胞白血病患儿作为观察组，另选112例性别、年龄与观察组相匹配的健康体检儿童作为对照组。检测两组血清GPAA1、SF、OPN表达水平，分析不同危险度的急性淋巴细胞白血病患儿血清GPAA1、SF、OPN表达水平的差异性，观察急性淋巴细胞白血病患儿的血栓发生情况，通过受试者工作特征曲线（ROC）下面积（AUC）评价血清GPAA1、SF、OPN预测急性淋巴细胞白血病患儿发生血栓的效能。结果：观察组血清GPAA1、SF、OPN表达水平均高于对照组（P＜0.05）；在低危、中危和高危的急性淋巴细胞白血病患儿中，血清GPAA1、SF、OPN表达水平有差异（P＜0.05）；经Spearman相关性分析，血清GPAA1、SF、OPN表达水平与儿童急性淋巴细胞白血病危险度呈正相关（P＜0.05）；在112例急性淋巴细胞白血病患儿中，发生血栓12例，占10.71%；经多因素Logistic回归分析，血清GPAA1、SF、OPN均是急性淋巴细胞白血病患儿发生血栓的独立预测因素（P＜0.05）；经ROC曲线分析，血清GPAA1、SF联合OPN预测急性淋巴细胞白血病患儿发生血栓的AUC为0.901。结论：血清GPAA1、SF、OPN与儿童急性淋巴细胞白血病危险度密切相关，联合预测患儿发生血栓的效能较好，对此病的诊治具有重要指导意义。     

Detection of the vulnerable coronary atheromatous plaque. Where are we now?

Atherosclerosis is a progressive process with potentially devastating consequences and has been identified as the leading cause of morbidity and mortality, especially in the industrial countries. The underlying mechanisms include endothelial dysfunction, lipid accumulation and enhanced inflammatory involvement resulting in plaque disruption or plaque erosion and subsequent thrombosis. However, it has been made evident, that the majority of rupture prone plaques that produce acute coronary syndromes are not severely stenotic. Conversely, lipid-rich plaques with thin fibrous cap, heavily infiltrated by inflammatory cells have been shown to predispose to rupture and thrombosis, independently of the degree of stenosis. Therefore, given the importance of plaque composition, a continuously growing interest in the development and improvement of diagnostic modalities will promptly and most importantly, accurately detect and characterize the high-risk atheromatous plaque. Use of these techniques may help risk stratification and allow the selection of the most appropriate therapeutic approach.     

大鼠实验性血栓模型的建立及其评价

根据Ｖｉｒｃｈｏｗ血栓形成原理,采用机械性损伤内膜,同时降低血流速度方法制备大鼠实验性血栓模型。结果显示,利用此方法制备血栓模型成功率为７８．４％,血栓平均长度８．５３±１．４２ｍｍ,血栓形成后,腹主动脉的收缩功能明显下降。     

Gastrin levels and gastric emptying times in rhesus monkeys with a history of acute gastric dilatation

Abstract: Abnormal gastric motility has been suggested as a possible causative factor for acute gastric dilatation observed in nonhuman primates. To evaluate gastric motility in a colony, fasting serum gastrin immunoreactivity and gastric emptying times were assessed in rhesus monkeys that had survived single episodes of acute gastric dilatation. These were paired with age- and weight-matched control monkeys from the same colony. Neither gastric emptying times nor gastrin assays were significantly different between the acute gastric dilatation and control groups.     

Another method to prevent venous thrombosis in microsurgery: an in situ venous catheter

Free-flap failure is in the order of 4 to 10 percent. Heparin is more effective at preventing venous thrombosis than arterial thrombosis. This study was undertaken to investigate the efficacy of delivering heparin at a high dose locally but low dose systemically (heparin infusion via a catheter placed proximal to the venous anastomosis) to prevent venous thrombosis in microsurgery. A model of venous thrombosis was first established by a venous inversion graft in the rat femoral vein (this was performed in seven animals and resulted in 100 percent thrombosis). Saline and heparin were delivered proximal to the inverted vein graft to assess the effect of each in preventing venous thrombosis. Flow/patency distal to the inverted vein graft was assessed by observation under the microscope, the milk test, and rate of flow (flowmeter). Saline infused via a catheter proximal to the venous inversion graft resulted in 100 percent thrombosis in 10 animals. Heparin (100 U/ml at 2 to 3 ml/hour) infused through a catheter for 2 hours proximal to the anastomosis resulted in flow in all 10 animals during the infusion. Blood was also taken before beginning the procedure (control) and after the heparin infusion distal to the anastomosis (local partial thromboplastin time) as well as in the contralateral femoral vein (systemic). The control for all animals that received heparin was <3 minutes. The systemic partial thromboplastin time after heparin infusion was <3 minutes in seven animals, 3.3 minutes in two animals, and >7 minutes in one animal. The local partial thromboplastin time distal to the inverted vein graft was >10 minutes in nine animals and 3.7 minutes in one animal. The study also had a clinical component, in which a catheter was placed in a vein of the free flap, and heparin was infused over 5 days. This technique has been used in 83 consecutive free flaps. In three recent free flaps performed on the limbs, the local partial thromboplastin time (close to the anastomosis) was raised but the systemic time was normal. This technique offers a method in preventing venous thrombosis in microsurgery. It is simple to implement and is not associated with the systemic complications of heparin.     

恶性肿瘤并发急性下肢深静脉血栓形成的病因分析与治疗

目的：探讨恶性肿瘤患者并发急性下肢深静脉血栓（deep vein thrombosis of the lower extremity,DVT）的形成原因、诊断要点与治疗、护理及预防措施,为相关治疗提供参考。方法：回顾性分析了我院22例恶性肿瘤并发下肢深静脉血栓患者的临床病理表现,诊断方式及采取的治疗与护理措施,所有患者采用小-中等剂量尿激酶溶栓、同时予以低分子肝素钠抗凝、低分子右旋糖酐及丹参川芎嗪注射液辅助治疗,部分患者采取切除根治手术,分析比较患者的疗效。结果：采取上述治疗后21例患者取得了满意的效果,其中1例患者经治疗半月后效果不明显,进一步检查确诊为恶性淋巴瘤,还有1例患者经治疗好转出院3个月后再次出现对侧下肢深静脉血栓,进一步检查确诊为胆管癌。结论：DVT患者经联合抗凝、溶栓、祛聚、扩血管等综合治疗效果明显,以DVT为首发表现的患者治疗效果不佳或再发应及早考虑恶性肿瘤,以免漏诊,耽误原发病的治疗。     

COX-2-dependent delayed dilatation of cerebral arterioles in response to bradykinin

Bradykinin (BK) is released in the brain during injury and inflammation. Activation of endothelial BK receptors produces acute dilatation of cerebral arterioles that is mediated by reactive oxygen species (ROS). ROS can also modulate gene expression, including expression of the inducible isoform of cyclooxygenase (COX-2). We hypothesized that exposure of the brain to BK would produce acute dilatation, which would be followed by a delayed dilatation mediated by COX-2. To test this hypothesis in anesthetized rats, BK was placed twice in cranial windows for 7 min, after which the windows were flushed to remove residual BK. The two BK exposures were separated by 30 min. Each BK exposure produced acute dilatation of cerebral arterioles, after which diameter rapidly returned to baseline. Over the subsequent 4.5 h after the second BK exposure, arterioles dilated 48 +/- 8%. Treatment of the cranial window with NS-398, a selective COX-2 inhibitor, or dexamethasone, significantly attenuated the delayed dilatation. Aminoguanidine, a selective inhibitor of inducible nitric oxide synthase, did not alter the delayed dilatation. Cotreatment of cranial windows with BK, superoxide dismutase, and catalase also prevented the delayed dilatation. In separate experiments, exposure of the cortical surface to BK upregulated leptomeningeal expression of COX-2 mRNA. Our results suggest that acute, time-limited exposure of the brain to BK produces delayed dilatation of cerebral arterioles dependent on expression and activity of COX-2.     

The Cutting Balloon--a new technology?

The Cutting Balloon consists of a standard balloon dilatation catheter with four microtome-sharp blades that incise the plaque and minimize arterial wall trauma. It was used in 31 patients; nine had calcified arteries, ten had non-compliant lesions, three had in-stent restenosis and nine had aorto-ostial lesions. Seventeen lesions were predilated, 28 were post-dilated and 18 required stent implantation. The procedure was very effective in aorto-ostial lesions, non-compliant lesions that were not responsive to high-pressure balloon dilatation, and was partially successful in calcified arteries. It has a very specific niche in selected lesions.     

急性右下肢深静脉血栓的临床治疗分析

目的:探讨右下肢深静脉血栓的临床治疗方法。方法:对我院2015年6月-2017年6月收治的63例右下肢深静脉血栓形成患者进行回顾性分析,从小腿周径差、彩超检查及造影3方面对疗效进行评价,并统计导管接触溶栓后患者复查肺部增强CT情况。结果:63例患者中,57例进行导管接触溶栓+下腔静脉滤器,6例进行导管接触溶栓+下腔静脉滤器+肺动脉碎栓、溶栓。治疗后,患者小腿周径差较治疗前明显降低,差异具有统计学意义(P0.05)。患者显效26例,有效28例,好转8例,无效1例,临床治愈率为85.7%。63例下腔静脉滤器,取出60例,3例留置为永久性滤器。新增肺栓塞12例,无致死性肺栓塞发生。结论:导管接触溶栓对右下肢深静脉血栓的治疗效果较好,但导管接溶栓时有较高肺栓塞发生率,应积极放置下腔静脉滤器。     

导管引导介入治疗急性中高危肺动脉栓塞临床研究

目的:评估导管引导介入治疗急性中高危肺动脉栓塞的有效性及安全性。方法:顾性分析2012年1月至2018年6月在柳州市工人医院血管外科诊治的112例急性中高危肺动脉栓塞患者资料。根据治疗方案分单纯抗凝组(共38例)、导管介入+抗凝治疗组(共74例),对比两组肺动脉压及肺动脉栓塞严重指数降低情况、肺栓塞症状改善率、住院时长和出血并发症发生率;以其随访中肺栓塞复发率和慢性血栓性肺动脉高压发生率。根据介入方案不同,介入治疗组包括AngioJet机械吸栓(共13例)、猪尾导管碎栓及溶栓(61例);分别对比两种介入方案术前及术后的动脉血氧分压、指脉氧、心率及肺动脉压、弥勒指数评估治疗效果。结果:两组术前人口学特征、发病时间、DVT并发率、肺动脉压、肺动脉栓塞严重指数等无明显差异(P均0.05)。介入治疗组在降低肺动脉压及肺动脉严重指数、症状的改善率、缩短住院时间上明显优于单纯抗凝组(P分别为0.000、0.001、0.01、0.003);而相关出血并发症发生率无统计学差异(P0.05)。通过分别对比介入治疗两种方案的术前及术后动脉血氧分压、指脉氧、心率及肺动脉压、弥勒指数,两种治疗方案在这五个指标均有明显改善(P值均0.05)。随访6月至7年,肺栓复发率在单纯抗凝组、导管介入+抗凝治疗组分别为10.5%、6.8%,统计学差异显著(P=0.004);慢性血栓性肺动脉高压发生率分别为5.3%、1.4%,统计学差异显著(P=0.000)。结论:导管引导介入治疗对急性中高危肺动脉栓塞治疗是安全有效的,且可明显降低复发及慢性肺动脉高压的发生率。     

Catheter-based impedance measurements in the right atrium for continuously monitoring hematocrit and estimating blood viscosity changes; an in vivo feasibility study in swine

Hematocrit is the most important determinant of whole blood viscosity and it affects thrombosis. As hematocrit can be measured accurately in vitro by using an electrical impedance technique, aim of the present study is to investigate the diagnostic potential of using this technique in vivo to continuously monitor hematocrit.

Characteristics of a special catheter for in vivo measurement of electrical resistivity in blood in the right atrium are described. In five anesthetized swine hematocrit is monitored continuously with this catheter while different levels of hemoconcentration are induced. In addition, blood viscosity is increased by inducing ‘acute phase’ reaction the day before surgery, resulting in variable degree of elevated fibrinogen levels in the five swine. Good reproducibility of the resistivity measurements (S.D.<0.01) and excellent correlation between resistivity data in vivo and hematocrit levels in each swine are found (r²=0.95–0.99). Furthermore, stepwise regression analysis of data from all swine shows a highly significant contribution also of other important parameters of blood viscosity, such as fibrinogen, total protein and temperature (cumulative r²=0.97).

Determining hematocrit continuously in vivo by electrical resistivity measurements with a catheter in the right atrium is feasible and these measurements correlate significantly also with other important parameters of blood viscosity.     

An absorbable catheter system for use in microvascular and peripheral vascular surgery: an experimental study in the canine.

An absorbable catheter for use in regional anticoagulation in microvascular and peripheral vascular surgery was studied in 20 sites in 10 adult beagle dogs to answer three questions: (1) Could the polyglycolic acid and trimethylene carbonate catheter withstand intraarterial pressures of infusion and completely absorb over a predictable time interval? (2) Could the catheter be filled with heparin and maintain patency for reuse after a 24-hour interval? (3) Could the catheter be placed in a side branch of a major artery and, after catheter dissolution, maintain long-term patency of the primary feeding artery? The catheters were completely absorbed from 24 to 34 weeks following implantation. The catheters were able to withstand intraarterial pressures, and no evidence of significant thrombosis of the primary feeding artery was seen in any animal studied. No complications of catheter leak, hematoma formation within the catheter placement sites, or sepsis were noted in any of the 20 catheter sites studied.     

The two-headed swan

Pulmonary artery catheterization is a frequent procedure for hemodynamic monitoring in critically ill patients or high-risk surgical patients. Mechanical and infectious complications are recognized, though catheter dysfunction and malposition are more frequent and often require clinical intervention. We present the case of a Swan-Ganz catheter with the appearance of a mechanical fracture at the distal end, which required clinical and radiographic investigation to determine the nature of the aberrancy. The evaluation of a malfunctioning pulmonary artery catheter (PAC) is a frequent occurrence in the intensive care unit and requires careful clinical consideration and radiographic examination.     

Letter: On the administration of prostaglandins as a pre-operative means of cervical dilatation

Prostaglandin (PG) administration by the intramuscular or extraamniotic route has been reported to be a safe and reliable means of effecting cervical dilatation prior to 1st trimester abortion by suction curettage. At the Mulago Hospital, Kampala, a minimum of 5 cases of 1st trimester abortions were performed weekly using the Karman cannula (KC), a flexible polyethylene catheter which lessens the risk of cervical dilatation. In none of the cases was cervical dilatation required for insertion of a KC of sufficient diameter. Paracervical block with procaine 2% (10 ml) was used for analgesia; in rare cases, 10 mg of diazepan was administered orally or intravenously as a preoperative medication. Complications encountered included: 1) perforation of the uterine fundus; 2) metritis; and 3) retained products of conception. With proper instrumentation, cervical dilatation is no longer required for 1st trimester abortions. PG administered for cervical dilatation is no longer justified because it is time consuming, a source of additional expense, inconvenient, and is associated with uterine cramps and gastrointestinal side effects. In occasional cases, as in undue cervical resistance, the use of PGs may be justified.     

Long-term Carotid Access in the Goat: Observations on Application of a Totally Implantable Catheter System

The investigation of metabolism of individual organs and tissues in vivo requires simultaneous measurements of arterio-venous concentration differences. Long-term metabolic studies require frequent and convenient access to veins and arteries of the relevant organs or tissues, and if blood samples are obtained by repeated veni — or arteriopuncture, difficulties may arise due to vessel thrombosis and an increasing apprehension of the goat during time. Arterial punctures are considered more painful than venipuncture, according to human patients. In the conscious goat, arteriopuncture may induce bleating, dilatation of the pupil, increased heart rate, blood glucose and free fatty acid levels, which may bias the results of a metabolic study (Linzell 1963). Furthermore, it is important to avoid situations which contribute negatively to the welfare of the goat. Establishment of permanent exteriorized carotid loops does not eliminate these problems and has a disadvantage of being vulnerable to injury. Jha et al. (1961) reported that 3 out of 10 goats died from haemorrhages, due to loop injury. The carotid artery may surgically be relocated to a subcutaneous position, which makes it less vulnerable, but also less accessible for percutaneous puncture (Tavenor 1969). Our experience with such subcutaneous relocated artery loops is that scar tissue formation is so strong after being catheterized 3-4 times, that further catheterization requires specialized assistance. The artery is eventually closed by fibrous tissue. An alternative to the repeated percutaneous puncture of subcutaneously relocated artery loops is the establishment of chronic indwelling arterial catheters, where the tip of the catheter is exteriorized to the skin. This method is well described (Huntington et al. 1989), but requires a dressing of the exteriorisation site, and restrain of the goat, in order to protect the tip from being pulled out. Therefore, we describe a modification of a totally implantable catheter system, developed for human intra-arterial long-term delivery of drugs, for permanent catheterization of the common carotid artery of goats. The entire access system of this catheter is under the skin.     

Acute Gastric Dilatation in Anorexia Nervosa

Two patients with anorexia nervosa were treated on a general surgical unit for acute gastric dilatation. In both cases the dilatation rapidly followed an increase in the usual low dietary intake of the patients, and the ingestion of extra food may have initiated the acute episode. Conservative treatment with parenteral fluids, nasogastric intubation, and then a gradual return to a normal diet proved a satisfactory method of management. In one patient the anorexia itself was improved.     

Optimal duration of dual antiplatelet therapy after percutaneous coronary intervention or after acute coronary syndrome

To prevent recurrent ischaemic events, dual antiplatelet therapy (DAPT) is the standard of care after percutaneous coronary intervention and in the treatment of acute coronary syndrome. Recent evidence supports an adjusted DAPT duration in selected patients.The current paper aims to encourage cardiologists to actively search for patients benefiting from either shorter or prolonged duration DAPT and proposes an algorithm to identify patients who are likely to benefit from such an alternative strategy.Individualised DAPT duration should be considered in high-risk anatomic and/or clinical subgroups or in patients at increased haemorrhagic risk with low ischaemic risk. Both thrombotic and haemorrhagic risk should be assessed in all patients. In patients undergoing percutaneous coronary intervention, the interventional cardiologist could advise on the minimal duration of DAPT. However, in contrast to the minimum duration of DAPT for stent thrombosis prevention, longer duration DAPT is aimed at prevention of spontaneous myocardial infarction, and not at stent thrombosis, and thus the key to success is to treat the patient’s overall thrombotic risk.The advice on the duration of DAPT must be documented in the patient’s records and communicated with the treating physician and general practitioner. DAPT duration should be reassessed at least on a yearly basis.