Acute airway obstruction following placement of a subclavian Hickman catheter

The purpose of this case report is to describe the events, intervention, and aetiology which led to acute airway obstruction in an adult patient after the placement of a Hickman catheter. Airway obstruction secondary to superior vena cava obstruction occurred after placement of a subclavian vein Hickman catheter. This was felt to occur, in part, to a narrowed superior vena cava as evident by subclavian venography. It resulted in emergency oral tracheal intubation to relieve airway obstruction. Shortly after removal of the Hickman catheter, the signs of superior vena cava obstruction syndrome resolved and the patient was extubated without incidence. It is concluded that, although rare, the serious complication of acute airway obstruction can occur after placement of a Hickman catheter.     

Slicer and tissue retrieval system for excisional endoscopic surgery

Extraction of large specimens risks detachment of malignant cells within the peritoneal cavity and contamination of the parieties with resultant seedling implantation at the access wounds. Therefore, extraction is best conducted through a rip-proof sleeve-retrieval system which creates a third space in which the specimen can be sliced under visual control. Slicing of tissue is preferable to morcellation or disintegration since it preserves the structural integrity of the tissue and thereby does not jeopardize histopathological examination and staging of excised tumors. Of the two types of tissue-slicing mechanisms investigated, the compression-moving blade system (CMB) was found to be superior to wire-cutting devices. A prototype CMB slicer has been developed which has been tested experimentally and is currently undergoing clinical evaluation.     

Pediatric intestinal transplantation

Advancements in donor management, organ preservation and operative techniques, as well as immunosuppressive therapies, have provided children with intestinal failure and its complications a chance not only for enteral autonomy but also long-term survival through intestinal transplantation (ITx). First described in the 1960’s, experience has grown in managing these complex patients both pre- and post-transplant. The goals of this review are to provide a brief history of intestinal transplantation and intestinal rehabilitation in pediatric patients, followed by focused discussions of the indications for ITx, induction and maintenance immunosuppression therapies, common post-operative complications, and outcomes/quality of life post-transplant.     

Finite Element Model Determination of Correction Factors Used for Measurement of Aortic Diameter via Conductance

Traditional methods for estimating the slope and offset volume V _P for determining real-time chamber volume by the conductance catheter technique are not suited to measurements made in the aorta due to the relatively low resistivity of the aortic wall. We developed three distinct three-dimensional finite element models of the conductance catheter and surrounding tissues in order to predict and V _P and to examine the nature of the electric field near the aortic wall. A heterogeneous isotropic model of the catheter, aorta and surrounding tissues accurately predicted the values of and V _P . A homogeneous anisotropic model was developed to examine the effects of anisotropy of blood and the layers of the aortic wall on measured values of resistance, and V _P . This model demonstrated that anisotropy of blood and aortic wall tissue can increase the values of both and V _P . Finally, a three-dimensional homogeneous isotropic rectangular model allowed examination of the effects of catheter position. This model showed small effects of catheter position on measured resistance (9.7% increase) and larger effects on (21.2% decrease) and V _P (41.9% increase). We conclude the following: the FEA models may lead to accurate estimate values of and V _P in vivo. The unique anisotropic conductive properties of the layers of the aortic wall contribute to the high observed values of and V _P in the aorta. Finally, catheter position has a proportionately greater effect on and V _P than on measured resistance. The results of this study should assist in the determination of aortic mechanical properties using conductance catheter measurements of vessel dimension. © 1999 Biomedical Engineering Society. PAC99: 8719Nn, 8719Rr, 8719Uv, 0270Dh, 8717Aa     

房室结折返性心动过速射频消融后的电生理改变与复发率的关系

目的：探讨房室结折返性心动过速（ＡＶＮＲＴ）射频消融术后的电生理改变及不同手术终点与复发率的关系。　方法：本组５６ 例ＡＶＮＲＴ患者慢径消融前、后作各项电生理参数测定,并随访观察远期疗效。　结果：３８ 例慢径消失者（Ａ组）无一例复发,残存慢径１２ 例（Ｂ组）有一例复发（８．３３％ ）,残存慢径有１～２ 个心房回波者６例（Ｃ组）有２例复发（３３．３％ ）。５３ 例无复发者消融前后的房室束最大值（Ａ－Ｈｍ ａｘ ）分别为（２８０±２７）和（１９６±５６）ｍ ｓ（Ｐ＜０．０１）,快径不应期分别为（３３０±４４）和（２８７±３１）ｍ ｓ（Ｐ＜ ０．０１）。而３ 例复发者消融前、后的Ａ－Ｈｍ ａｘ分别为（２８７±３１）和（２６２±３８）ｍ ｓ（Ｐ＞ ０．０５）,快径不应期分别为（３２４±３８）和（３１３±２８）ｍ ｓ（Ｐ＞ ０．０５）。　结论：ＡＶＮＲＴ的复发与慢径残存和Ａ－Ｈｍ ａｘ 及快径不应期无明显改变有关。     

射频能量时间递增法治疗房室结折返性心动过速

目的：评估射频能量时间递增法治疗４０ 例房室结内折返性心动过速的疗效及安全性。　方法：标测到理想的慢径路靶点后,从小功率（１０～１５ Ｗ）、短时间（５～１０ ｓ）放电开始,如出现交界区早搏或交界区心律,逐渐增加放电功率（２０～２５ Ｗ）和持续时间（３０～６０ ｓ）,并密切观察房室传导阻滞的迹象和先兆。　结果：临床治愈率９７．５％ ,无一例产生严重并发症。　结论：射频能量时间递增法是一种安全、高效的治疗方法。     

血清唾液酸含量诊断胃疾病探讨

测定慢性浅表性胃炎１５例,萎缩性胃炎５例,胃溃疡１５例,胃癌９例患者血唾液酸（ＳＡ）的含量。结果表明在４组胃疾病中,胃癌、胃溃疡ＳＡ比慢性浅表性胃炎高。经统计学处理（方差分析）差别有高度显著性（Ｆ＝９１７,Ｐ＜００１）。结论：定期测定ＳＡ含量,对胃部疾患的随访和病情变化有着重要意义。     

导管法测定大鼠肺循环血流量的研究

目的：研究一种新的导管法测定肺循环血流量。方法：分离右侧颈外静脉,将塑料导管自右侧颈外静脉插入,经上腔静脉、右心房和右心室插入肺动脉。用上海产ＳＪ—４２型四导生理记录仪记录生理参数。结果：肺循环血流量可按公式ＱＰ＝ＭＰＡＰ·△ＱＭＰＡＰ－ＭＰＡＰ计算,式中△Ｑ是每分钟自肺循环流入容量测定计的血量,算得的ＱＰ＝２９．６２±３．７３ｍｌ／ｍｉｎ,在大鼠的肺循环血流量正常范围之内。结论：该方法精确而且操作简便     

Paraplegia after thoracotomy--not caused by the epidural catheter

BACKGROUND: Paraplegia and peripheral nerve injuries may arise after general anaesthesia from many causes but are easily ascribed to central block if the latter has been used. CASE REPORT: A 56-yr-old woman, with Bechterev disease but otherwise healthy, was operated with left-sided thoracotomy to remove a tumour in the left lower lobe. She had an epidural catheter inserted in the mid-thoracic area before general anaesthesia was started. Bupivacaine 0.5% 5 ml was injected once and the infusion of bupivacaine 0.1% with 2 micrograms/ml fentanyl and 2 micrograms/ml adrenaline (5 ml/h) started at the end of surgery. The patient woke up with total paralysis in the lower limb and sensory analgesia at the level of T8, which remained unchanged at several observations. Laminectomy, performed 17 h after the primary operation, showed a large piece of a haemostatic sponge (Surgicel) compressing the spinal cord, which was then decompressed but the motor and sensory deficit remained virtually unchanged both then and a year later. CONCLUSIONS: This case shows--once again--that although central blocks may cause serious neurological complications and paraplegia, other causes are possible and have to be considered. However, all patients with an epidural catheter must be monitored for early signs and symptoms of an intraspinal process and the appropriate treatment has to be instituted instantly.     

Radiofrequency ablation in children

Radiofrequency (RF) catheter ablation has ushered in a new era in the management of patients with symptomatic tachyarrhythmias. By providing the ability to cure the underlying arrhythmic substrate, RF catheter ablation obviates the need for life-long antiarrhythmic drugs. In the reported series, the success has been high and the complications have been infrequent and relatively minor. Not unexpectedly, RF catheter ablation has become the treatment of choice for patients with symptomatic paroxysmal tachyarrhythmias. The role of radiofrequency catheter ablation in infants and small children remains controversial, and awaits a larger experience and longer follow-up data.