Postoperative Radiological Follow-up Research Articles

Postoperative recovery after suspension suture placement at the site of esophagojejunal anastomosis after total gastrectomy: Comparison of two surgical techniques.

Despite improvements, survival rates for gastric cancer remain low, even in developed countries, confirming the role of primary and secondary prevention. This study aims to demonstrate the role of additional suspension sutures on the esophagojejunal anastomosis (EJA) to strengthen the anastomosis, i.e., relieve the mechanical suture. A retrospective cohort study was conducted from 2011 to 2022 at the Clinic for Surgery, University Clinical Center Tuzla, Bosnia and Herzegovina. The experimental group consisted of patients placed with a suspension suture at the esophagojejunal anastomosis (EJA) site after total gastrectomy. The control group was patients without a suspension suture. The clinical and laboratory parameters available from the medical history were analyzed, X-ray passage, surgical complications, non-surgical complications, the length of hospitalization, the postoperative course, time of onset of postoperative complications, postoperative radiological follow-up and endoscopic postoperative follow-up were then analyzed. A total of 212 patients were included in the study: 87 in the experimental group with suspension sutures on the EJA and 125 in the control group without suspension sutures on the EJA. The two cohorts did not differ in other clinicopathologic parameters except perineural invasion, which was more prevalent in the control group. Patients in both groups were anemic and elevated values of C reactive protein (CRP) and decreased levels of proteins, albumin and globulin, with no significant difference between the two groups. The most common general complication was pleural effusion (28%), followed by pneumonia (∼22%). The most common complication in the experimental group was an intraabdominal abscess, while in the control group, it was a surgical wound infection. Our study did not show a statistically significant difference between the two analyzed EJA techniques created with a circular stapler, when it comes to postoperative course and outcome in patients with gastric cancer.

Current Trends in Knee Arthroplasty: Are Italian Surgeons Doing What Is Expected?

Objectives: The purpose of this study is to evaluate Italian surgeons’ behavior during knee arthroplasty. Materials and Methods: All orthopedic surgeons who specialized in knee replacement surgeries and were members of the Italian Society of Knee, Arthroscopy, Sport, Cartilage and Orthopedic Technologies (SIGASCOT) between January 2019 and August 2019 were asked to complete a survey on the management of knee arthroplasty. Data were collected, analyzed, and presented as frequencies and percentages. Results: One-hundred and seventy-seven surgeons completed the survey and were included in the study. Ninety-five (53.7%) surgeons were under 40 years of age. Eighty-five surgeons (48%) worked in public hospitals and 112 (63.3%) were considered “high volume surgeons”, with more than 100 knee implants per year. Postero-stabilized total knee arthroplasty was the most commonly used, implanted with a fully cemented technique by 162 (91.5%) surgeons. Unicompartmental knee arthroplasty (UKA) was a rarer procedure compared to TKA, with 77% of surgeons performing less than 30% of UKAs. Most common TKA pre-operative radiological planning included complete antero-posterior (AP) weight-bearing lower limb radiographs, lateral view and patellofemoral view (used by 91%, 98.9% and 70.6% of surgeons, respectively). Pre-operative UKA radiological images included Rosenberg or Schuss views, patellofemoral view and magnetic resonance imaging (66.1%, 71.8% and 46.3% of surgeons, respectively). One hundred and thirty-two surgeons (74.6%) included an AP weight-bearing lower limb X-ray one year after surgery in the post-operative radiological follow-up. Furthermore, 119 surgeons (67.2%) did not perform a post-operative patellofemoral view because it was not considered useful for radiological follow-up. There was no uniformity in the timing and features of post-operative follow-up, with 13 different combinations. Conclusions: Italian surgeons perform TKA more commonly than UKA. Pre-operative TKA planning is quite uniform rather than UKA planning. Despite literature evidence, there is no agreement on follow-up. It may be useful to create a uniform checklist, including correct timing and exams needed. This analysis is also part of a society surgical educational project for training doctor.

Simple biliary cysts of the liver can be lined by mucinous epithelium.

Simple biliary cysts of the liver are described to be lined by biliary epithelium and may be managed nonsurgically or by deroofing only. By contrast, its important differential diagnosis-mucinous cystic neoplasm (MCN)-is at least focally lined by mucinous epithelium, has malignant potential, and therefore should be resected. Following anecdotal observations in routine diagnostic practice, the following case series was assembled to confirm whether simple biliary cysts of the liver can be lined by mucinous epithelium. Detailed clinicoradiological review, including postoperative follow-up, was also completed to assess whether the presence of mucinous epithelium had any associations, including a risk of hepatobiliary neoplasia. Histological review of 21 simple biliary cysts received as surgical specimens over a 3- year period confirmed an absence of ovarian-like stroma in all cases. The lining epithelium of seven cysts showed focal supranuclear/apical mucin, as confirmed histochemically. Cysts with mucinous epithelium were generally larger and more often showed histological evidence of previous haemorrhage than cysts without this epithelium. There were no other statistically-significant differences in clinicoradiological features between cysts with and without mucinous epithelium, including at postoperative radiological follow-up. Focal mucinous epithelium can be present in at least one-third of surgically-managed, simple biliary cysts of the liver. Such epithelium may be metaplastic and should not be misinterpreted to indicate a diagnosis of MCN but, apart from this, appears to have no clinical significance. Ovarian-like stroma may therefore be the only histological feature that reliably distinguishes MCN from simple biliary cyst.

An early experience of lumbopelvic fixation techniques at Alexandria University

BackgroundThe aim of lumbopelvic fixation is to obtain a solid fusion across the lumbosacral junction. There are many indications for lumbopelvic fixation, namely, spinal deformity in cases requiring long segment fusion, pelvic obliquity, pseudarthrosis at the lumbosacral junction, infection or osteolytic tumors, and pathologic fractures. The classical iliac screws should be contained within the iliac bone but have some disadvantages: excessive soft tissue dissection needed for accurate insertion, screw prominence with patient discomfort, and usually, a side connector is needed to connect the iliac screws to the rest of the construct. Lumbopelvic fixation by insertion of S2 alar-iliac (S2AI) screws was recently described to overcome these disadvantages. In this study, the authors present the initial results for the evaluation of lumbopelvic fixation through the insertion of S2AI screws in 19 consecutive patients operated in the neurosurgery department at Alexandria University.ObjectiveThe aim of the study was to evaluate the efficacy and complications of lumbopelvic fixation through the use of S2 alar-iliac screws.MethodsThe authors conducted a retrospective cohort study of data collected from the database of patients who underwent lumbopelvic fixation through the insertion of S2AI screws from 2016 to 2019 at a single institution.ResultsThere were 19 patients indicated for lumbopelvic fixation, operated by modern instrumentation systems using lumbar pedicle screws and S2 alar-iliac screws. There were 14 females and 5 males. The mean age at the time of the operation was 38.6 ± 19.4 years with a range from 11 to 65 years. There was a total of 37 S2AI screws, screw diameter was 7mm in all cases regardless of age, and the length of the screws ranged from 50 mm in a young female patient (11 years) to 90 mm in an old male patient (60 years). Two screws were inserted per patient except in one case with congenital scoliosis due to the bad bone quality and the multiple iatrogenic wrong paths. Postoperative VAS score for back pain was greatly improved in all patients after the first 6 months of follow-up from 8 ± 1.5 to 3.5 ± 1.2 (paired t-test = 11.182, P<0.001). All patients had a good spinal range of motion to maintain normal daily activities without any significant restrictions after the first 3 months of follow-up. Immediate postoperative radiological follow-up had revealed 2 cases of posterior pelvic breaches and one case with anterior pelvic breach but without clinical manifestations with no need for revision. Two cases of unilateral screw breakout were observed after the first 6 months of follow-up. Removal of screws after the first 6 months was done in one patient with spondylodiscitis due to the unresolved infection and screw pullout.ConclusionThe insertion of S2AI screws is an effective technique for lumbopelvic fixation with a relatively low rate of complications. Pelvic breaches are the commonest complications encountered during the insertion of S2AI screws, although no significant clinical morbidities were reported.

Colloid cysts of the third ventricle in children.

The rarity of colloid cysts in children makes it difficult to characterize this entity and offer meaningful advice on treatment. Infrequent case reports exist, but to date there has been no age-specific assessment. The purpose of this study was to define any differences between children and adults who are evaluated and treated for colloid cysts of the third ventricle. Patients with colloid cysts were reviewed and stratified by age. Individuals ≤ 18 years of age were defined as pediatric patients and those > 18 years of age as adults. Clinical and radiographic data, treatment, and postoperative outcomes were compared between both groups. Bivariate analysis was conducted using the Fisher exact test for categorical variables and Mann-Whitney U-test for continuous variables. Of 132 endoscopic resections (121 primary, 10 secondary, and 1 tertiary) of a colloid cyst, 9 (6.8%) were performed in pediatric patients (mean age 14.1 years, range 9-18 years) and 123 (93.2%) were performed in adult patients (mean age 43.8 years, range 19-73 years). Cases were found incidentally more commonly in pediatric than adult patients (66.7% vs 37.4%, p > 0.05), and pediatric patients had lower rates of hydrocephalus than adult patients (11.1% vs 63.4%, p < 0.05). Acute decompensation at presentation was found in 8 adults (6.5%) but no children. Complete cyst removal (88.9% vs 90.2%, p > 0.05) and length of stay (1.6 days vs 2.9 days, p > 0.05) were not significantly different between the groups. Postoperative complications (6.5% in adults, 0% in children) and recurrence (2.4% in adults, 0% in children) were rare in both groups, and there were no treatment-related deaths. The mean postoperative radiological follow-up was longer in pediatric patients (45 months, range 4-89 months) than adults (44.1 months, range 1-171 months). While differences exist between children and adults regarding colloid cyst presentation, these are in keeping with the predicted evolution of a slow-growing lesion. Consistent with this observation, children had lower rates of hydrocephalus and a smaller mean maximal cyst diameter. Contrary to the published literature, however, sudden deterioration was not observed in pediatric patients but occurred in adult patients. In this limited pediatric sample size, the authors have not recorded any postoperative complications or recurrences to date. These encouraging results with endoscopic removal may positively impact future decisions related to children given their protracted life expectancy and projected rates of progression.

Minimally invasive removal of lumbar intradural extramedullary lesions using the interlaminar approach.

OBJECT Posterior midline laminectomy or hemilaminectomy has been successfully applied as the standard microsurgical technique for the treatment of spinal intradural pathologies. However, the associated risks of postoperative spinal instability increase the need for subsequent fusion surgery to prevent potential long-term spinal deformity. Continuous efforts have been made to minimize injuries to the surrounding tissue resulting from surgical manipulations. The authors report here their experiences with a novel minimally invasive surgical approach, namely the interlaminar approach, for the treatment of lumbar intraspinal tumors. METHODS A retrospective review was conducted of patients at the Second Affiliated Hospital of Zhejiang University School of Medicine who underwent minimally invasive resection of lumbar intradural-extramedullary tumors. By using an operative microscope, in addition to an endoscope when necessary, the authors were able to treat all patients with a unilateral, paramedian, bone-sparing interlaminar technique. Data including preoperative neurological status, tumor location, size, pathological diagnosis, extension of resections, intraoperative blood loss, length of hospital stay, and clinical outcomes were obtained through clinical and radiological examinations. RESULTS Eighteen patients diagnosed with lumbar intradural-extramedullary tumors were treated from October 2013 to March 2015 by this interlaminar technique. A microscope was used in 15 cases, and the remaining 3 cases were treated using a microscope as well as an endoscope. There were 14 schwannomas, 2 ependymomas, 1 epidermoid cyst, and 1 enterogenous cyst. Postoperative radiological follow-up revealed complete removal of all the lesions and no signs of bone defects in the lamina. At clinical follow-up, 14 of the 18 patients had less pain, and patients' motor/sensory functions improved or remained normal in all cases except 1. CONClUSIONS When meeting certain selection criteria, intradural-extramedullary lumbar tumors, especially schwannomas, can be completely and safely resected through a less-invasive interlaminar approach using a microscope, or a microscope in addition to an endoscope when necessary. This approach was advantageous because it caused even less bone destruction, resulting in better postoperative spinal stability, no need for facetectomy and fusion, and quicker functional recovery for the patients. Individualized surgical planning according to preoperative radiological findings is key to a successful microsurgical resection of these lesions through the interlaminar space.

Dento-maxillo-facial phenotype and implants-based oral rehabilitation in Ectodermal Dysplasia with WNT10A gene mutation: Report of a case and literature review

PurposeTo report the dento-craniofacial phenotype of a family affected by a WNT10A HED and to describe the implant-based oral rehabilitation of a patient presenting a severe oligodontia linked to this mutation. A molecular hypothesis concerning the involvement of Wnt-β-catenin pathway in implant osteointegration will be proposed. Material and methodsPatients affected by a WNT10A mutation were included from a large group of HED patients. WNT10A gene was sequenced in second intention for patients negative for EDA-EDAR-EDARADD mutations. Dento-craniofacial phenotype was described based on clinical and radiological data. ResultsSevere oligodontia was observed in the patient affected by a compound heterozygous mutation of WNT10A gene. CT exams showed marked maxillary bone hypoplasia in the posterior areas with a sub-normal mandible treatment consisted in the placement of 4 mandibular implants and in 2 implant-supported bridges. In the maxilla, an autogenous bone graft was indicated. The post-operative radiological follow-up showed partial bone resorption of the grafts, treated with ramus bone shaving and a membrane, followed by the placement of 4 maxillary implants. ConclusionPatients affected by WNT10A HED require multi-disciplinary dental diagnosis and treatment. A close post-operative radiological follow-up appears necessary given the biological functions of Wnt-β-catenin in bone repair.

Gamma Knife surgery anterior capsulotomy for severe and refractory obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a challenging psychiatric condition associated with anxiety and ritualistic behaviors. Although medical management and psychiatric therapy are effective for many patients, severe and extreme cases may prove refractory to these approaches. The authors evaluated their experience with Gamma Knife (GK) capsulotomy in treating patients with severe OCD. A retrospective review of an institutional review board-approved prospective clinical GK database was conducted for patients treated for severe OCD. All patients were evaluated preoperatively by at least one psychiatrist, and their condition was deemed refractory to pharmacological and psychiatric therapy. Five patients were identified. Gamma Knife surgery with the GK Perfexion unit was used to target the anterior limb of the internal capsule bilaterally. A single 4-mm isocenter was used; maximum radiation doses of 140-160 Gy were delivered. All 5 patients were preoperatively and postoperatively assessed for clinical response by using both subjective and objective metrics, including the Yale-Brown Obsessive Compulsive Scale (YBOCS); 4 of the 5 patients had postoperative radiological follow-up. The median clinical follow-up was 24 months (range 6-33 months). At the time of radiosurgery, all patients had YBOCS scores in the severe or extreme range (median 32, range 31-34). At the last follow-up, 4 (80%) of the 5 patients showed marked clinical improvement; in the remaining patient (20%), mild improvement was seen. The median YBOCS score was 13 (range 12-31) at the last follow-up. Neuroimaging studies at 6 months after GK treatment demonstrated a small area of enhancement corresponding to the site of the isocenter and some mild T2 signal changes in the internal capsule. No adverse clinical effects were noted from the radiosurgery. For patients with severe OCD refractory to medications and psychiatric therapy, GK capsulotomy afforded clinical improvement. Further study of this approach seems warranted.

Is Routine Postoperative Radiologic Follow-up Justified in Adolescent Idiopathic Scoliosis?

Study DesignRetrospective review. ObjectivesTo determine whether routine periodic radiographic examination is worthwhile in adolescent idiopathic scoliosis (AIS) patients undergoing instrumented fusion with third-generation implants. Summary of Background DataIn common practice, patients who have undergone surgery for idiopathic scoliosis are followed up for a minimum of 2 years by clinical assessment and routine radiographic study at 3, 6, 12, and 24 months. The radiation related to these examinations is not negligible. To our knowledge, the use of routine radiographic follow-up after posterior spinal fusion for adolescent idiopathic scoliosis has not been evaluated. MethodsWe retrospectively analyzed full-spine X-rays and clinical records from the first 2 postoperative years of 43 patients. We sought any clinical feature (eg, pain, deformity progression, material protrusion) justifying X-ray, and any relevant radiologic finding (eg, loss of correction, instrumentation loosening, junctional kyphosis). ResultsExcluding the immediate postoperative films, 14.8% of X-rays were clinically justified, 8.3% were associated with a relevant finding, and 4.3% led to a therapy change. All patients with clinical deformity progression had a relevant X-ray finding. Pain was associated with a relevant finding in 23.5% of cases (positive predictive value, 0.1); 7.4% of films with no clinical justification showed a relevant finding (negative predictive value, 0.86). Lower Risser sign increased the risk of having a relevant radiographic finding (p < .05). ConclusionsWith the current use of third-generation implants, routine biplanar postoperative X-rays at 3, 6, 12, and 24 months do not seem to be justified in AIS and should be avoided in mature, asymptomatic patients.

METHODS OF DIAGNOSIS AND TREATMENT OF ANKLE FRACTURES - THE OPINION OF MEMBERS AND SUPPORTERS OF THE POLISH FOOT AND ANKLE SOCIETY

The present paper is based on a survey distributed among the participants of the 3rd Congress of the Polish Foot and Ankle Society in Jastarnia on April 22-24, 2010. A clinical description and imaging data of a hypothetical patient with a typical ankle fracture were used to identify current methods of diagnosis and treatment of such injuries in Poland. The participants were orthopaedists. Eighty-five questionnaires were distributed and 54 (63%) were completed and returned. Most respondents correctly recognized the fracture mechanism and identified the type of fracture. They preferred operative treatment, but were not able to apply the AO classification. The answers regarding post-operative radiological follow-up did not provide for long-term follow-up and the suggested methods of imaging to detect disruption of the tibiofibular syndesmosis were insufficient. The recommendations concerning the timing and staging of post-operative weight bearing as well as antithrombotic prophylaxis complied with current standards.

Complete washout of a colloid cyst on MRI after partial removal by endoscopic approach

Dear Sir, We would like to bring to your attention a case of progressive disappearance of a colloid cyst after endoscopic resection of a minor portion of the lesion, as documented by magnetic resonance imaging (MRI). This right-handed 50-year-old male presented with general fatigue associated with disturbance of concentration and intermittent headache. Clinical neurological examination was normal. A computed tomography (CT) and an MRI of the brain revealed a cystic lesion in the area of the foramen of Monro in the roof of the third ventricle. On CT, the lesion was hyperdense. On MRI, the lesion was hyperintense on T1-weighted images and hypointense on T2-weighted images. The cyst obstructed the foramen of Monro (Fig. 1) leading to hydrocephalus of both lateral ventricles. Image-guided endoscopic removal of the lesion was performed through a right frontal approach under general anaesthesia (Fig. 2). Only a minor portion of the lesion was removed by the endoscopic approach considering the risk of traction on the fornix through the chosen trajectory. No complication occurred during surgery. Histological examination showed the typical aspect of a colloid cyst. A postoperative MRI, performed 48 h after the surgery, revealed only a slight decrease of the dimensions of the cyst (Fig. 3). There was a clear decrease in the size of the lateral ventricles, suggesting a better permeability of the foramen of Monro. Postoperatively, the symptoms of the patient disappeared and he was discharged 5 days later. Postoperative MRIs performed at 3 months and every year until 4 years after surgery surprisingly revealed a progressive disappearance of the colloid cyst with complete permeability of the foramen of Monro (Fig. 4). Third ventricular colloid cysts are rare benign lesions which are typically hyperintense on T1 and hypointense on T2-weighted MRI [1–9]. The correlation of the T1weighted MR imaging hyperintensity of the cyst and a high concentration of cholesterol in colloid cyst has been documented by Maeder et al. [7]. This was also confirmed in our patient at histological examination. Although recurrence of colloid cysts after total removal is exceptional, the postoperative radiological follow-up of a partially removed lesion has not been reported in the literature [5, 6, 10–12]. Our case shows that even partial removal of a colloid cyst can result in total washout of the lesion without recurrence during a 4-year follow-up. T. Robert (*) :M. Levivier :C. Pollo Department of Neurosurgery, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland e-mail: Thomas.robert43@gmail.com

Advantages of Perforator Flaps in Reconstruction of Complex Defects of the Head and Neck

Microsurgical transfer of vascularized tissue during the past three decades has allowed highly complicated postoncologic defects in the head and neck region to be reconstructed. Recently, perforator flaps have been used to reduce postoperative pain, shorten hospital stay, and lessen donor-site complications. These flaps are offsprings of previously known musculocutaneous and fasciocutaneous flaps and are harvested with preservation of the underlying muscular and fascial structures. The vascularized skin and soft-tissue envelope is supplied by perforating branches from the parent vessel. Less is known about the performance of these flaps in the head and neck region. During a 4-year period, 22 patients at our institution underwent reconstruction of the head and neck region with deep inferior epigastric perforator (DIEP) or thoracodorsal artery perforator (TDAP) flaps. All but one of the flaps survived. Advantages noted include: (1) longer vascular pedicles, (2) less postoperative pain, (3) less donor-site deformity, (4) improved aesthetic outcome, (5)potential for a neurosensory flap, (6) potential for an osteocutaneous flap, and (7) ease of postoperative radiologic follow-up. The DIEP flap can be harvested concurrent with oncologic resection, with the patient in the supine position. The TDAP flap is dissected with the patient in the decubitus position, creating an additional step to change operative position, and separates extirpative and reconstructive stages.

Systematic Postoperative Radiologic Follow-up in Patients With Non–Small Cell Lung Cancer for Detecting Second Primary Lung Cancer in Stage IA—Invited Critique

Hypothesis: Systematic postoperative evaluation of patients with non-small cell lung cancer will identify treatable second primary lung cancer and local recurrences. Design: Retrospective review from January 1, 1996, to December 31, 2000. The follow-up protocol included an annual computed tomographic examination of the chest with interval chest radiography every 4 months for 2 years and every 6 months for 3 additional years. Setting: A National Cancer Institute-designated comprehensive cancer center. Patients: One hundred twenty-four patients with resected non-small cell lung cancer. Main Outcome Measures: Number and size of second primary and locally recurrent tumors, secondary surgical procedures, and survival of patients who underwent resection. Results: The median diameter of resected second primary tumors detected by computed tomography was 14 mm (range, 8-28 mm) and by chest radiography was 26.5 mm (range, 23.0-35.0 mm) (P<001). Of 14 patients with second primary lung cancer treated surgically, 9 were without evidence of disease at a median of 20 months (range, 4-56 months), 2 were alive with disease at 13 and 37 months, 2 died of unrelated causes but without evidence of disease at 7 and 35 months, and 1 died intraoperatively of a cardiac arrhythmia. Conclusions: Systematic follow-up of non-smail cell lung cancer, including annual computed tomography, detects second primary lung cancer in stage IA. Limited pulmonary resections are often feasible in these patients. Locally recurrent lung cancer is infrequently resectable.

Systematic postoperative radiologic follow-up in patients with non-small cell lung cancer for detecting second primary lung cancer in stage IA.

Systematic postoperative evaluation of patients with non-small cell lung cancer will identify treatable second primary lung cancer and local recurrences. Retrospective review from January 1, 1996, to December 31, 2000. The follow-up protocol included an annual computed tomographic examination of the chest with interval chest radiography every 4 months for 2 years and every 6 months for 3 additional years. A National Cancer Institute-designated comprehensive cancer center. One hundred twenty-four patients with resected non-small cell lung cancer. Number and size of second primary and locally recurrent tumors, secondary surgical procedures, and survival of patients who underwent resection. The median diameter of resected second primary tumors detected by computed tomography was 14 mm (range, 8-28 mm) and by chest radiography was 26.5 mm (range, 23.0-35.0 mm) (P<.001). Of 14 patients with second primary lung cancer treated surgically, 9 were without evidence of disease at a median of 20 months (range, 4-56 months), 2 were alive with disease at 13 and 37 months, 2 died of unrelated causes but without evidence of disease at 7 and 35 months, and 1 died intraoperatively of a cardiac arrhythmia. Systematic follow-up of non-small cell lung cancer, including annual computed tomography, detects second primary lung cancer in stage IA. Limited pulmonary resections are often feasible in these patients. Locally recurrent lung cancer is infrequently resectable.

Ｈａｒｄｙ術後に生じた蝶形骨洞嚢胞例

A case of sphenoid sinus mucocele which occurred after transsphenoidal hypophysectomy for pituitary adenoma is reported. The patient was 44-year-old female complaining of visual complication and general fatigue.The mucocele wall was resected as much as possible via a transnasal approach with endoscopy, and a drainage was routed into the nasal cavity.Mucocele recurrence was not detected within a 14-month follow-up period.This case suggests that the postoperative radiologic follow-up should be performed after removal of pituitary tumors to detect sphenoid sinus mucocele as well as the tumor recurrence.

チタンクリップのCT, MRIおよび力学的特性

Titanium alloy currently used in medicine contains 6% of aluminium and 4% of vanadium. It has long been used as titanium plates or pedicle screws. While it is considered to be safe as a material, its durability, especially when used as aneurysm clips, is not clear.Sugita type titanium aneurysm clips are made in shapes similar to cobalt alloy (Elgiloy) clips except for spring diameter, which was enlarged by 10%. Their neuroradiological and mechanical characteristics are compared with Sugita cobalt clips. CT was taken at 120 KV, 300 mA by hanging a clip on a thread in a plastic bottle filled with saline. Cobalt clips caused strong high density artifacts around the clip with a low density linear shadow along its long axis. The shapes of titanium clips could be seen since they were surrounded by only faint artifacts. T1 weighted (TR: 500ms, TE: 20ms) and T2 weighted (TR: 4100ms, TE: 80ms) MRI images were taken by hanging a clip on a thread in a plastic bottle filled with baby-oil (Johnson & Johnson). The cobalt clip caused on both T1 and T2 weighted images a candle-flame-shaped high-signal-intensity artifact by longitudinal image and triangular high-signal-intensity artifact separated into three blocks on the axial image. Artifacts by titanium clips were about 1/3 that of cobalt clips but the difference was not as big as CT images.The closing force of titanium clips was measured at 2mm from the tip of the blades, which were opened by 1.5mm. After manually repeating full opening and closing of the clips by clip appliers 500 times, the reduction of closing force remained less than 3%. The closing force of a #2 titanium clip measured at 1mm step from the tip toward the spring base showed an increase in a hyperbolic curve, from 120 to 240g, which was similar to that a #2 cobalt clip. The closing force of a # 2 titanium clip measured at 1.5 mm from the tip when the blades were opened by 0.5mm step from 0.5 to 3.5 mm increased in a straight line from 120 to 160g, which was similar to that of a #2 cobalt clip.These results show that Sugita titanium clips are durable within tested conditions and they have similar characteristics of closing force to cobalt clips. They seem to be quite useful especially for postoperative radiological follow-up. However, accidental scissoring of titanium clips that are commercially available in Japan has been reported. This may be due to weakness of titanium alloy in both tensile and compression strength, which is only one half that of cobalt alloys. Thus, titanium clips do not seem to be able to totally replace cobalt clips but, with care, they can be used in easily clippable and uncomplicated aneurysms.