Mechanical and radiation isocenter coincidence: an experience in linear accelerator alignment.

As part of the commissioning procedure of a linear accelerator at our cancer center, the defining laser lines were aligned with the optical and radiation isocenter of the linac. When a mechanical checkout jig was set up at the same point, a discrepancy of 4 mm resulted when the gantry was moved from 0 degrees to 180 degrees. Extensive measurements, some with custom-designed devices, confirmed the observations and provided an explanation. Even though the mechanical isocenter is within the specified tolerance of 1-mm radius, the clinically observable discrepancy of 4-mm results from the noncoincidence of the mechanical and radiation isocenters. The clinical significance of the final setup is discussed and future commissioning procedures are recommended.     

Surgical Management of PICA Aneurysm and Incidental Facial Nerve Schwannoma: Case Report.

We report a patient with a posterior inferior cerebellar artery (PICA) aneurysm and an incidental facial nerve schwannoma at the cerebellopontine angle (CPA). A 46-year-old woman presented with the sudden onset of a severe headache, nausea, and vomiting. She had no other abnormal neurological symptoms and signs. Computed tomography (CT) showed hemorrhage in the fourth ventricle. Cerebral angiography demonstrated an aneurysm arising from the tonsillomedullary segment of the left PICA. A facial nerve schwannoma was incidentally found as the aneurysm was being clipped. The aneurysm was clipped via a left transcondylar approach. Subsequently, the schwannoma (2 x 3 x 2 mm) was resected from the facial nerve fascicles, and the facial nerve was preserved. Postoperatively, the patient developed mild to moderate dysfunction of the facial nerve (House-Brackmann grade III [H-B III]) but her hearing was intact. Both a facial nerve schwannoma involving the CPA and an aneurysm involving the PICA can be managed through the transcondylar approach. An asymptomatic facial nerve schwannoma can be resected safely with minimal facial nerve dysfunction.     

Crystal deposits in the human intervertebral disc: implications for disc degeneration.

BACKGROUND CONTEXT: Although crystal deposition in cartilage and synovial fluid has received much attention, crystal formation and the role that crystal deposits play are virtually unexplored in the intervertebral disc. In articular cartilage matrix, crystal deposits are associated with altered extracellular matrix (ECM) and cell phenotypic features, but crystal deposition in the human intervertebral disc has received much less attention. PURPOSE: To determine the incidence of crystal deposits in the annulus and to evaluate associated disc cell and ECM features. STUDY DESIGN/SETTING: Human intervertebral disc annulus tissue was obtained in a prospective study of the presence of crystals in the disc ECM. Human Subjects Institutional Review Board approved experimental studies. PATIENT SAMPLE: Two hundred eight sequential disc specimens were submitted from surgical disc procedures performed on individuals with herniated discs, degenerative disc disease, or recurrent disc herniation. During this same time period, three disc specimens were received from nonsurgical donors and added to the study population. OUTCOME MEASURES: Histologic features with special attention to crystal deposition. METHODS: Specimens were processed undecalcified and examined for the histologic presence of crystal deposits and ECM features around the crystals. RESULTS: The proportion of specimens containing crystals was determined to be 14.7%; crystals displayed varying sizes, morphology, and polarized light birefringence features. Pyrophosphate crystals were most common, but oxalate-like crystals were also present. ECM in crystal regions showed previously recognized alterations. CONCLUSIONS: This study shows that the incidence of crystal deposits in discs is approximately 15% and is thus a relatively common occurrence. These data are important because masses of crystals not only disrupt disc ECM but may also accelerate preexisting degenerative changes via an elevation in matrix metalloproteinases (as previously recognized in cartilage). Because failure of the structural integrity of the disc can result in annular tears and subsequent disc herniation, the mechanisms of crystal formation and the relationship between crystals and disc degeneration merit further investigations.     

458例尿路结石成分分析

目的 探讨西安地区尿路结石的成分状况，为临床防治提供帮助。方法对458例尿路结石标本进行化学成分测定，并结合临床资料进行比较。结果尿路结石男性发病多于女性，男、女比为2．1：1，20一50岁为高发年龄，上尿路结石明显多于下尿路结石，上、下尿路结石之比为10．5：1。结石成分以混合结石占多数，为325例（71％），其中以草酸钙，磷酸钙与尿酸的混合结石为主。对比混合性结石及单纯性结石发现，各种成分所占比例基本一致。结论结石成分分析对于了解结石成因、预防结石形成和复发具有重要的意义。     

Significance of malperfusion syndromes prior to contemporary surgical repair for acute type A dissection: outcomes and need for additional revascularizations.

OBJECTIVE: The aim of this study was to assess the significance of malperfusion syndromes in patients with acute type A aortic dissection following a contemporary surgical management algorithm and the effects on morbidity, hospital mortality, and long-term survival. We believe that obliteration of the primary tear site with restoration of flow in the true aortic lumen results in decreased need for revascularization of malperfused organ systems. METHODS: Our operative approach aims at replacing the entire ascending aorta, resuspension of the aortic valve with repair or replacement of the sinus segment, and routine open replacement of the arch under hypothermic circulatory arrest with retrograde cerebral perfusion with obliteration of false lumen at the distal arch/proximal descending thoracic aorta, thus reestablishing normal flow in the descending thoracic true lumen. From January 1993 to December 2004, 221 consecutive patients underwent repair of acute type A aortic dissection at our institution. Data were collected retrospectively and prospectively. Various types of malperfusion syndromes were present in 26.7% of patients. The organ systems with malperfusion were as follows: cardiac, 7.2%; cerebral, 7.2%; ileofemoral, 12.7%; renal, 4.1%; mesenteric, 1.4%; innominate, 5.4%; and spine, 2.2%. RESULTS: Coronary malperfusion required coronary revascularization in 62.5% of cases. Distal revascularization was needed in 42.9% of patients with ileofemoral malperfusion. Patients with malperfusion were more likely to suffer perioperative myocardial infarction (p<0.001), postoperative coma (p=0.012), delirium (p=0.011), sepsis (p=0.006), acute renal failure (p=0.017), dialysis (p=0.018), and acute limb ischemia (p<0.001). The in-hospital mortality was 30.5% in patients presenting with any malperfusion syndrome while only 6.2% in patients without malperfusion syndrome (p<0.001). Both cardiac (p=0.020) and cerebral malperfusions (p<0.001) were risk factors for in-hospital mortality. The actuarial long-term survival in patients with malperfusion syndrome was estimated by Kaplan-Meier methods to be 67.8%+/-6.1% at 1 year, 54.0%+/-7.0% at 5 years, and 43.1%+/-8.0% at 10 years and for patient without malperfusion 82.7%+/-3.0% at 1 year, 66.3%+/-3.9% at 5 years, and 46.1%+/-6.7% at 10 years (log rank 2.55, p=0.110). Cerebral malperfusion was a significant risk factor for decreased long-term survival (p=0.0002). CONCLUSIONS: The occurrence of malperfusion in patients with acute type A dissection is associated with significant increased risk of in-hospital mortality and complications. Additional revascularization is generally needed in patients with coronary malperfusion and ileofemoral malperfusion. Patients presenting with cardiac and cerebral malperfusions have a high hospital mortality and preoperative cerebral malperfusion is associated with dismal long-term survival.     

The tuberous breast revisited.

BACKGROUND: The tuberous breast presents a problem for which many surgical solutions have been described. Current teaching describes how the tuberous breast deformity is the result of skin shortage as well as herniation of breast tissue through the nipple-areola complex. However, through careful clinical observation we now believe that the only abnormality present is herniation of breast tissue through the nipple-areola complex. METHODS: Using this principle, we have refined a one-stage surgical procedure that can be used to correct any type of tuberous breast deformity. Since 2001 we have performed our technique on a series of 13 tuberous breasts of widely varying appearances in eight patients (age 17-24 years) with a follow up varying between 3 and 56 months. Our new understanding of the tuberous breast deformity has also made it possible to develop an objective, reproducible method for defining the tuberous breast based on the degree of areola herniation. RESULTS: All patients reported high levels of satisfaction with the procedure. Assessment of the results by an independent panel of attending surgeons showed all results to be good/excellent. Moreover, the results have improved with time and no revisions have been needed. Our method of defining the tuberous breast (based on the ratio of areola herniation:areola diameter) enabled us to identify a cut-off to decide (objectively) when a breast was tuberous. This allowed us to anticipate when an areola reduction/tightening procedure would be necessary to avoid a 'double-bubble' deformity. CONCLUSION: We propose a one-stage surgical procedure which is applicable to all degrees of tuberous breast deformity. The results appear to confirm our theory that the only abnormality present in the tuberous breast is herniation of breast tissue through the nipple-areola complex. In patients with small breasts and a tuberous deformity, correction of the herniation changes the tuberous breast into a simple hypoplastic breast. The volume deficit can then be corrected by augmentation (if desired by the patient). In patients with sufficient breast volume, correction of the herniation alone will correct the deformity.     

Treatment of congenital cystic adenomatoid malformation-does resection in the early postnatal period increase surgical risk?

OBJECTIVE: The recent development of fetal ultrasonography has allowed for an increasing number of prenatal diagnoses for congenital cystic adenomatoid malformation (CCAM). However, the appropriate surgical timing of these patients has not been studied as of yet. The aim of this study is to suggest a safe strategy for the treatment of CCAM by identifying the relationship between the timing of surgery and postoperative outcome. METHODS: Between 1987 and 2003, 40 patients (28 males, 12 females) underwent surgical resection for CCAM. The mean age was 38.6+/-9.1 (2 days-13 years) months. CCAM was diagnosed by prenatal ultrasonography in eight patients. Early operations were performed in four out of the eight. Operation was deferred until 2-12 months of age for the remaining four patients. RESULTS: Type I CCAM was found in 20 patients, type II in 20 and no patient exhibited type III. Five patients had associated pectus excavatum anomaly. There were no cases of operative mortality. Seventeen minor postoperative complications developed in 16 patients (40.0%): prolonged chest tube drain in 10, wound infection in 4, and 1 case of pneumonia, empyema and pleural space, respectively. The average hospital stay was 11.8 (6-29) days. During the mean follow-up period of 67.5 months, one patient died of accidental aspiration 7 months after operation during the postoperative recovery course of Ravich operation for pectus excavatum. The remaining patients reported doing well with normal physical activity. All five patients who underwent surgery at the age of under 1 month did not exhibit increased postoperative morbidity. CONCLUSIONS: We concluded that surgery for CCAM could be safely performed in all age groups with satisfactory long-term outcomes. It is suggested that early elective surgical correction can be recommended for a patient whose diagnosis was made in utero.     

对耳轮过度前突畸形的整复

对耳轮过度前突为对耳轮的角度过锐，致使耳轮的位置相应后移，表现为与招风耳完全相反的畸形。畸形虽不十分明显，但影响美观。自１９９２年４月开始应用患侧耳廓软骨和耳后皮瓣对５例患者８只外耳进行治疗得到满意效果。认为文中所述方法是矫正对耳轮过度前突畸形的良好方法。     

颅内生殖细胞瘤综合治疗

报告５０例颅内生殖细胞瘤，手术治疗１９例，放射治疗４３例。综合治疗后临床症状改善４１例，无效２例。随访３２例，其中恢复正常工作或学习者１４例，生活能自理１２例，生活部分需人帮助４例，死亡２例。５年生存率为５０％。推荐放疗为首选治疗手段，并对合并颅内压增高及多发性、复发性肿瘤的治疗作了讨论。