C-arm Fluoroscopic Guidance Research Articles

The Role of Microperc in the Treatment of Symptomatic Lower Pole Renal Calculi

The treatment of symptomatic lower pole (LP) calculi poses a challenge because of lower clearance rates. We present our experience with microperc in the treatment of LP renal calculi. We retrospectively evaluated the symptomatic patients with LP renal calculi who underwent microperc between August 2011 and June 2012 from two referral hospitals. Patients were included only in cases of failure after shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS) and according to patient preference. The percutaneous renal access was performed using the 4.8F "all-seeing needle" with C-arm fluoroscopy or ultrasonographic guidance with the patient in the prone position. Stone disintegration was established using a 200 μm holmium:yttrium-aluminum-garnet laser fiber. A total of 21 patients (mean age 37.3 ± 20.1 years) with LP stone underwent microperc. The mean body mass index was 28.6 ± 6.0 kg/m(2), and the mean stone size was 17.8 ± 5.9 (9-29) mm. The duration of surgery and fluoroscopic screening was 62.8 ± 25.2 minutes and 150.5 ± 92.8 seconds, respectively. The patients were discharged after a mean 37.5 ± 14.4 hours of hospitalization time. The mean hemoglobin drop was 0.8 ± 0.6 (0.1-2.3) g/dL. Conversion to miniperc was necessitated in one patient with loss of vision. Stone-free status was achieved in 18 (85.7%) patients. Clinically insignificant residual fragments were observed in only one (4.8%). The procedure failed in two (9.5%) patients. A total of two minor complications (renal colic necessitating stent insertion and urinary tract infection) were observed postoperatively, none severe. Microperc is a feasible and efficient treatment modality for symptomatic LP calculi. Our results provide that microperc might take a part in case of SWL and RIRS failures or as an alternative to percutaneous nephrolithotomy or RIRS in the management of symptomatic LP calculi.

Preliminary study of the feasibility and accuracy of percutaneous peri-acetabular screw insertion in a porcine model

The aim of this pilot study was to assess a new method of training for peri-acetabular screw placement under indirect vision using standard C-arm fluoroscopy using a porcine model.Two novice orthopaedic residents placed 72 screws (36 each) about the acetabula of six porcine pelves under C-arm fluoroscopic guidance. Unsatisfactory screw position was noted in 22 of 72, with five instances of screw ingress into the hip joint. All of these cases occurred in the first half of each resident's series. Screw direction and final position improved over subsequent trials.This pilot study demonstrates that surgical simulation techniques are applicable in percutaneous screw fixation. Such an approach could be useful for both residents in training and more experienced surgeons who wish to perform this procedure in cases where it is appropriate.

Comparison of clinical effectiveness of cervical transforaminal steroid injection according to different radiological guidances (C-arm fluoroscopy vs. computed tomography fluoroscopy)

Background context Transforaminal steroid injection using C-arm fluoroscopy has been regarded as a useful method of treatment for cervical herniated disc. But C-arm fluoroscopy cannot identify soft tissue; so there is controversy about its safety and efficacy. Computed tomography (CT) fluoroscopy permits precise anatomical resolution and has the potential to offer a safer technique compared with C-arm fluoroscopy. Purpose This study was to identify the clinical effectiveness of CT fluoroscopy guidance in cervical transforaminal steroid injection compared with C-arm fluoroscopy guidance. Study design/setting Prospective randomized controlled study/spine hospital. Patients sample Patients with neck pain and radiating upper limb pain resulting from cervical disc herniation participated in the study. They were allocated into either the CT (CT group, N=51) or C-arm (C group, N=65) fluoroscopy guidance group. Outcome measure Numeric Rating Scale (NRS) pain score and Neck Disability Index (NDI) values were measured at pretreatment and 8 weeks after treatment. Successful pain relief and functional improvement were defined as a 50% or more reduction in NRS and at least 40% reduction in NDI compared with pretreatment one. Numeric Rating Scale and NDI efficiency were also calculated by the difference between pre and 8 weeks after treatment to validate the degree of change in pain reduction and functional improvement. Results After 8 weeks, both groups showed pain reduction and functional improvement. The CT group showed significantly the better outcomes in reduction of NRS for arm pain score and improvement of NDI. Whereas the CT group had no cases of side effects, the C group had 10 cases. Conclusions The CT group, without any side effects, showed the better effectiveness than the C-arm group in the improvement of radiating pain and functional status in patients with cervical disc herniation. Therefore, CT fluoroscopy can be a substitute for C-arm fluoroscopy in transforaminal steroid injection when treating patients with cervical disc herniation.

Efficacy of minimally invasive internal fixation to treat unstable of pelvic ring

Objective To analyze the clinical effectiveness of minimally invasive internal fixa-tion with cannulated screws to treat unstable fracture of pelvic ring. Methods From June 2007 to June 2010, 40 cases of patients with unstable fracture of pelvic ring, and without massive hemorrhage and nerve injury, were be given higher gross weight skeletal traction in 3～5 days after injury to correct the vertical shift, then be located by pelvic anteroposterior, inlet,outlet, obturator foramen loxosis and ilium loxosis X-ray radiograghs under C-arm fluoroscopic guidance accurately, and fixed the sacroiliac joint,pubic ramus,pubic symphysis and ilium with cannulated screws minimally invasively in 1 week.Results All the 40 cases were followed-up 8～24 months.The time of fracture healing was 3～4.5 months.The excellent and good rates were 92.5% according the Majeed criterion of therapeutical effect. Conclusions Minimally invasive internal fixation with cannulated screws to treat unstable fracture of pelvic ring has lesser injury and hemorrhage, better effectiveness of fixation, lower incidence of complication and is inexpensive. Key words: pelvic ring; internal fixation; stability; fracture

The safety and efficacy of PCNL with supracostal approach in the treatment of renal stones

Supracostal superior calyceal access has been shown to be the most suitable approach for staghorn calculi, calculi in the upper ureter, and complex inferior calyceal calculi. It is a good choice for direct access for most of the intrarenal collecting system and upper ureter. The aim of this retrospective study was to evaluate a single center data regarding the safety and efficacy of this approach for percutaneous renal stone surgery. A total of 597 renal units (597 cases) were treated with percutaneous nephrolithotomy from the March of 2000 to March of 2005. Supracostal approach was selected in 123 cases and infracostal approach in remaining 474 cases. The indications of supracostal approach in our cases were staghorn and complex inferior calyceal stones, and stones in the upper calyx or the upper ureter. All punctures were made by the urologist under C-arm fluoroscopic guidance in the prone position. The interspace between 11th and 12th rib was used in 116 patients (94%) and 10th-11th interspace in 7 cases (6%). The operative time, success rate, hospital stay, and complications were evaluated. The complete and relative success rates were 89.4 and 10.6%, respectively. The total complication rate was 13%. The success rate in the 10th-11th rib access and 11th-12th interrib access was 77 and 90%, respectively. Complete success rate was 100% in stone sizes less than 2 cm in diameter of upper ureteral and renal pelvic areas, and 77.4% of staghorn calculi. The total complication rate was 13% (16 cases), in which the most common of it was perioperative bleeding (5.7%; 7 cases). The supracostal approach was found to be effective as well as safe, with acceptable complications. It gives high stone clearance rates with acceptable morbidity rates and should be attempted in selected cases. The rate of pulmonary complications is higher with the supracostal approach. If the supracostal approach is indicated, it should be used with caution.

Removal of foreign body on cheek using endoscope and C-arm fluoroscopy

Traditional surgery to remove foreign bodies in the face carries a risk of postoperative morbidity with an injury to various an atomical structures, par- ticularly the facial nerve and parotid duct and gland. Endoscopy can be a great aid in the removal of foreign bodies in the max illofacial region. Surgical intervention using endoscope and/,or intraoperative images can be minimized, allowing the safe and precise removal of foreign bodies, and saving operating time. We report a case of the use of an endoscope and C-arm fluoroscopy guidance system to remove a very small foreign body.

Anatomic study of the axillary nerve in a Chinese cadaveric population: correlation of the course of the nerve with proximal humeral fixation with intramedullary nail or external skeletal fixation

The axillary nerve can be injured during external skeletal fixation with Schanz screws or proximal locking screws of intramedullary nails. Being aware of the axillary nerve's anatomic relationship to the proximal humerus is vital for avoiding complications. We investigated the relationship of the axillary nerve to surrounding bony landmarks by studying 88 axillary nerves in 44 embalmed cadaveric adult Chinese males. These measurements were then compared with the results from a similar study among Caucasians using the same reference points. We identified three significantly different parameters between our Chinese and the previously studied Caucasian subjects (P ≤ 0.05): the distances from the superior aspect of the humeral head to the axillary nerve (D1) (5.2 ± 0.7 vs. 6.09 ± 0.65 cm, respectively); surgical neck to axillary nerve (D2) (2.0 ± 0.7 vs. 1.72 ± 0.84 cm); and humeral length (D3) (29.0 ± 2.2 vs. 35.25 ± 5.7 cm). The D1 distance ranged from 4.0 to 6.7 cm; the D2 distance ranged from 1.0 to 4.1 cm; and the entire humeral length (D3) ranged from 23.3 to 33.3 cm. Iatrogenic injury to the axillary nerve could be reduced by placing pins and screws in proper directions using portable C-arm fluoroscopic guidance, drill-guided protective systems, and a mini-open-incision with muscle spreading and drill protective systems directly placed on the bone. Because of physical variability among individual patients and populations, surgeons should consider the possible courses of the axillary nerve when treating proximal humeral fractures.

Percutaneous cervical nucleoplasty and percutaneous cervical discectomy treatments of the contained cervical disc herniation

There were no studies in literature to compare the clinical outcomes of percutaneous nucleoplasty (PCN) and percutaneous cervical discectomy (PCD) in contained cervical disc herniation. A retrospective of patients with symptomatic contained cervical disc herniated were operated on with PCN and PCD from June 2003 to July 2005. Two-hundred and four patients initially fulfilled the study criteria, and 28 patients were lost in follow-up. The patients were categorized into different groups depending on the procedure by PCN (81 cases) or PCD (95 cases). The clinical outcomes, pain reduction, and segment stability were recorded during this study. Puncture of the needle into the disc space was accurately performed under C-arm fluoroscopy guidance in all cases and no intraoperative deaths were reported in our study. At the end, 176 cases had follow-up and 28 cases were lost, and the follow-up rate was 88.0% (81/92) in the PCN group and 84.8% (95/112) in the PCD group. The follow-up time ranged from 16 to 48 months (average 29 months), and on an average of 28.86 ± 4.52 months on PCN and 8.42 ± 3.21 months on PCD (t = -0.24, P = 0.81, >0.05). The operation time averages of PCN and PCD are 4.67 ± 1.16 and 11.95 ± 1.80, respectively (P < 0.01). The pain index improved from 7.12 ± 1.13 to 2.74 ± 0.89 (t = 27.03, P = 0.0000, <0.001) in PCN patients and from 7.18 ± 1.09 to 2.71 ± 0.91 (t = 29.57, P = 0.0000, <0.001) in PCD patients. Clinical results of PCN were excellent in 31 cases, good 32 cases, fair 13 cases, and poor 5 cases; for PCD, the results were 33, 42, 12, and 7 cases, respectively, and 1 in discitis. Good and excellent was 78.4% (77.8% in PCN and 79.5% in PCD, P > 0.05). There was one case of PCN that had the partial Perc-D SpineWand broken in the disc space, cannot be moved by the percutaneous cervical discectomy, and remained there itself. One of the cases had discitis in this study after PCD. Patient presented with neck pain and associated radicular pain and numbness in the left upper-limb after 8 days of PCD. There were no instable cases after procedures of PCN and PCD. There were no significant difference in stability of preoperatively and postoperatively between PCN and PCD (P > 0.05). PCN and PCD treatments of contained cervical disc herniation show good outcomes and there was no difference in the stability of cervical spine. PCN and PCD are safe, minimally invasive, and no differences were observed between the methods in clinical outcome.

BALLOON-ASSISTED CLIPPING OF A LARGE PARACLINOIDAL ANEURYSM

Surgical clipping and parent vessel reconstruction of wide-neck paraclinoid aneurysms can be very challenging. We report a case of a ruptured paraclinoid aneurysm which failed standard clipping techniques. We were able to reconstruct this aneurysm while providing proximal and distal control using an adjuvant endovascular balloon. We report the case of a 45-year-old woman presenting with a ruptured large paraclinoidal aneurysm, which involved a significant portion of the internal carotid artery wall. Repeated attempts at fenestrated clip placement resulted in slipping of the clip and occlusion of the parent artery. Ultimately, the aneurysm ruptured at the neck, and, despite trapping and direct aneurysmal suction decompression, significant bleeding was encountered. The bleeding point was packed, and, subsequently, endovascular access was obtained. A balloon was navigated and then inflated across the neck of the aneurysm using C-arm fluoroscopic guidance. The aneurysm was successfully clipped, and intraoperative angiography demonstrated no parent vessel stenosis. This case demonstrates a salvage procedure in the event of intraoperative rupture and inadequate interruption of local blood flow. Balloon inflation resulted in adequate hemostasis and provided intraluminal support for optimal clip placement while preserving the parent artery.

Extraforaminal Lumbar Interbody Fusion for the Treatment of Isthmic Spondylolisthesis

A preliminary study about extraforaminal lumbar interbody fusion (ELIF) technique for the treatment of isthmic spondylolisthesis. To introduce a new surgical fusion technique for isthmic spondylolisthesis with minimally invasive procedure. Posterolateral fusion, posterior lumbar interbody fusion, and anterior lumbar interbody fusion with posterior fixation are the options of the surgical treatment for isthmic spondylolisthesis. Still, complications can be related to these approaches. The authors tried to approach directly to lesion-the exiting nerve root, to decompress and to stabilize with minimally invasive procedure. Through extraforaminal approach, we can expose the exiting nerve root only to perform interbody fusion without intra-abdominal dissection or exposing central dura and traversing nerve root. Five patients with isthmic spondylolisthesis underwent ELIF with percutaneous pedicle screw fixation (PPF) between August 2005 and April 2007. In all subjects, the 3-cm-long posterior skin incisions were made bilaterally about 6 to 8 cm lateral from the midline. The multifidus muscle was separated with blunt dissection from the longissimus muscles. We identified the isthmus and neural foramen, removed fibrocartilage and the lateral border of ligamentum flavum covering the exiting nerve root, separated the soft tissue attached to the root and the transverse process, and retracted the root to perform discectomy. We prepared the endplates, cages with allograft, inserted them under C-arm fluoroscopic guidance, and performed the procedures on the contralateral side. After the arthrodesis, posterior instrumentation was augmented with PPF. Five patients underwent ELIF+PPF; despite a small number of cases, the outcomes were satisfactory. ELIF technique makes exposing only the exiting nerve root easy to perform interbody fusion without violating either the abdominal cavity or the posterior musculoligamentous and the bony stabilizers of the spine. This may be considered as one of the minimally invasive surgical options for isthmic spondylolisthesis.

Lumbosacral degenerative stenosis in the dog

Thirty-eight dogs with Hansen type II lumbosacral disc protrusion were treated with epidural infiltration of methylprednisolone acetate between the seventh lumbar vertebra and the sacrum. Epidural infiltration was carried out under C-arm fluoroscopic guidance at standardised intervals for the first three treatments and later on demand. Retrospective evaluation by owner questionnaire found that 79% of the animals were considered to have improved, and 53% were totally cured. Epidural infiltration with methylprednisolone acetate has a clinical outcome comparable to decompressive surgery and can be safely used as a less invasive alternative.

Interscalene brachial plexus block: depth and angle from the skin insertion point to the brachial plexus and to C6-7intervertebral foramen

Background: The angle and depth from the insertion point to the brachial plexus (BP) and C6-7 intervertebral foramen (IF) was examined to prevent critical complications of an interscalene brachial plexus block (ISBPB), such as an epidural or subdural injection of local anesthetics and spinal cord injury. Methods: Thirty patients (female = 12, male = 18), aged 20−64 years, undergoing shoulder or upper limb surgery were examined. ISBPB was performed at the interscalene groove intersecting the extended transverse line from the cricoid cartilage. A needle was then advanced towards the C6 transverse process (TP) and C6-7 IF under the C-arm fluoroscopic guidance. The depth and angle of the needle path intersecting the sagittal plane from the skin insertion point to BP, transverse process (TP) and IF were measured. Results: The mean depth of the needle from the insertion point to BP, TP and IF were 2.6 ± 0.3 cm, 3.2 ± 0.4 cm, 3.7 ± 0.3 cm in the female patients, and 2.7 ± 0.3 cm, 3.6 ± 0.5 cm, 4.1 ± 0.3 cm in the male patients. The mean angle of the needle path at the same point was 56.0 ± 7.2o (range, 42.0−65.0o), 54.2 ± 5.8o, 53.7 ± 4.4o in the female patients, and 59.3 ±8.3o (45.0−75.0o), 54.0 ± 6.3o, 54.9 ± 4.2o in male patients. There were significant differences in the depth from the skin to the TP and IF between males and females. Conclusions: These findings are expected to provide a guideline for more accurate needle placement and successful block during ISBPB.

Comparison of Radiation Exposure in Lumbar Pedicle Screw Placement With Fluoroscopy Vs Computer-Assisted Image Guidance With Intraoperative Three-Dimensional Imaging

Background/objective: Little is known about the long-term effects of chronic exposure to ionizingradiation. Studies have shown that spine surgeons may be exposed to significantly more radiation than thatobserved in surgery on the appendicular skeleton. Computer-assisted image guidance systems have beenshown in preliminary studies to enable accurate instrumentation of the spine. Computer-assisted image guidance systems may havesignificant application to the surgical management of spinal trauma and deformity. The objective of this study was to compare C-arm fluoroscopy and computer-assisted imageguidance in terms of radiation exposure to the operative surgeon when placing pedicle screw-rod constructsin cadaver specimens.Methods: Twelve single-level (2 contiguous vertebral bodies) lumbar pedicle screw-rod constructs (48screws) in 4 fresh cadavers were placed using standard C-arm fluoroscopy and computer-assisted imageguidance (Stealth Station with lso-C3D ).Pedicle screw-rod constructs were placed at L1-L2, L3-L4, and L5-S1 in 4 fresh cadaver specimens. Imaging was alternated between C-arm fluoroscopy and computer-assistedimage guidance with Stealth Station lso-C3D. Radiation exposure was measured using ringand badge dosimeters to monitor the thyroid, torso, and index finger. Postprocedure CT scans were obtained to judge accuracy of screw placement.Results: Mean radiation exposure to the torso was 4.33 ± 2.66 mRemfor procedures performed with standard fluoroscopy and 0.33 ± 0.82 mRem for procedures performed with computer-assisted image guidance. This difference was statistically significant (P = 0.012). Radiation exposure to the index finger and thyroid was negligible for all procedures. The accuracy of screw placement was similar for both techniques.Conclusions: Computer-assisted image guidance systems allow for the safe and accurate placement ofpedicle screw-rod constructs with a significant reduction in exposure to ionizing radiation to the torso of theoperating surgeon.

Multislice CT Fluoroscopy-assisted Cervical Transforaminal Injection of Steroids

A prospective study of 19 consecutive patients who underwent multislice computed tomography (CT)-guided cervical transforaminal steroid injection. To evaluate the feasibility and the outcome of cervical transforaminal steroid injection guided by multislice CT fluoroscopy. Cervical transforaminal steroid injection has been accepted as an effective therapeutic modality for radiculopathy that results from a cervical herniated disc or stenosis. However, there has been debate on the safety of the transforaminal approach technique, with C-arm fluoroscopy guidance, compared with the posterior interlaminar approach. We present an advanced approach technique for cervical transforaminal steroid injection guided by multislice CT fluoroscopy and the clinical outcomes. Nineteen consecutive patients presenting with radiating pain to the shoulder or arm had CT or magnetic resonance image scan findings compatible with cervical herniated disc or foraminal stenosis and were recruited to participate in this study. They underwent cervical transforaminal steroid injection using multislice CT fluoroscopy guidance up to 3 times with a minimal interval of 2 weeks. The participants were evaluated for the safety and efficacy of this technique for a follow-up period of 16 weeks. No serious complications were found during and after the procedures. Eleven patients received a second steroid injection but none required a third injection over the 16-week follow-up period. The mean visual analog scale score improved significantly at 2, 4, 8, and 16 weeks (P < 0.001). The multislice CT fluoroscopy-guided approach is feasible and a safe and effective approach for cervical transforaminal steroid injection. With the advantages of safety for the patient and precise placement of the needle for injection, this technique might be an additional option and may eventually replace the conventional C-arm fluoroscopy-guided cervical transforaminal steroid injection technique.

Treatment of Vertebral Tumor with Posterior Wall Defect Using Image-guided Radiofrequency Ablation Combined with Vertebroplasty: Preliminary Results in 12 Patients

To evaluate the safety and clinical benefit of vertebral tumor treatment by combined radiofrequency ablation (RFA) and vertebroplasty, for pain reduction in patients who are unable to benefit from noninvasive treatment methods. Twelve patients with painful vertebral tumors with posterior wall defect, in whom medical treatment together with radiation therapy and/or chemotherapy had failed, were treated with RFA combined with vertebroplasty. Procedures were performed using multislice CT-fluoroscopy and lateral C-arm fluoroscopic guidance. All patients had posterior wall defects of the vertebra being treated. Ten had lytic posterior wall destruction and two had posterior wall fracture. The visual analog scale (VAS) pain score was measured before, one week after, and three months after treatment. VAS patient satisfaction score was measured before and one week after treatment. The VAS score range was 0-20. The analgesic use was evaluated before and four weeks after treatment and complications were monitored. Combined RFA and vertebroplasty treatment was technically successful in all patients. Pain significantly decreased after treatment: the mean VAS pain score before treatment was 17.33 +/- 2.46 (range, 13-20) versus 9.25 +/- 4.81 (range, 2-18) one week after treatment (P < .001) and was 7.00 +/- 5.26 (range, 1-14) three months after treatment (P = .020). The mean VAS satisfaction score of all patients was 15.83 +/- 4.26 (range, 4-20). Analgesic use decreased after treatment. No serious treatment related complications occurred. RFA in combination with vertebroplasty for treating vertebral tumors with posterior wall defect appeared safe, and reduced pain substantially in patients who did not benefit from other noninvasive treatment methods.

Safety of supracostal punctures for percutaneous renal surgery

Supracostal superior calyceal access has been shown to be the most suitable approach for staghorn calculi, calculi in the upper ureter and complex inferior calyceal calculi, as well as for antegrade endopyelotomy. However, many urologists hesitate in using this approach because of the potential for chest complications. The aim of this study was to analyze one institution's data regarding the safety and efficacy of this approach for percutaneous renal surgery. A total of 890 renal units (762 patients) were treated with percutaneous renal surgery (849 percutaneous nephrolithotomy, 41 antegrade endopyelotomy) from July 1998 to July 2004. Supracostal access was obtained in 332 (37.3%) patients. The indications for a supracostal approach were ureteropelvic junction obstruction, staghorn and complex inferior calyceal calculi, and stones in the upper calyx or the upper ureter. All punctures were made by the urologist under C-arm fluoroscopic guidance in the prone position. The interspace between 11th and 12th rib was used in all except four patients in whom the puncture was made above the 11th rib. Eleven patients (3.31%) had a pleural breach presenting with fluid in the chest. Insertion of a chest tube was required in seven patients, while other four were managed conservatively. No patient had injury to the lung or other viscera. Hospital stay was not significantly prolonged as a result of the pleural breach in any patient. Except for staghorn calculi where multiple tracts were a necessity for maximal clearance, a single supracostal superior or middle posterior calyceal access served the purpose in 86% (177/205) of patients who underwent percutaneous surgery for renal or upper ureteric calculi. The supracostal superior calyceal approach was found to be effective as well as safe, with an acceptably low risk of chest complications.

TU-EE-A3-03: Automated Segmentation of Radiographic Fiducials for C-Arm Tracking

Purpose: Intraoperative quantitative C-arm fluoroscopy guidance depends on discerning the relative pose of images (pose recovery). A possible method is to use radiographic fiducials visible in fluoro images [1,2]. We propose a robust and fast method for segmenting fiducials designed for brachytherapy applications. Methods and materials: The fiducial contains points, lines and ellipses made from BBs and wires[1]. The algorithm integrates the a-priori knowledge of fiducial's mechanical construction in a cleverly devised workflow. The BB segmentation is achieved using morphological top-hat transform. This information serves as a heuristic input to line segmentation realized by a curve tracing algorithm which operates on edge image, followed by augmenting information from intensity image. Once the lines are segmented, this information feeds to the ellipse extraction step. For ellipse segmentation, intensity image is morphologically processed to eliminate background noise, followed by elimination of BB-s and lines from the information obtained in prior steps. The resulting image consists of only ellipse segments. A fast variation of Hough transform is used to rectify the full ellipse from the segments. Results: The fiducial algorithm identified all the features (BBs, lines and ellipses) visible to human eye in all ten clinical images. Next the accuracy of fiducial segmentation was assessed numerically by feeding the results to the pose recovery algorithm of [1]. The fiducial was moved on an accurate mechanical platform (as ground truth) while the C-arm was stationary. We reconstructed the relative poses with an accuracy of 1.2 mm in translation and 0.3 degrees in rotational based on the segmented fiducials. Conclusions: The algorithm makes effective use of a-priori knowledge and combines the techniques of morphological segmentation, curve tracing, and Hough transform, resulting in a novel curve segmentation strategy.

Fluoroscopy-Assisted Retroperitoneal Laparoscopic Renal Surgery in Children

To investigate the use of C-arm fluoroscopy for locating small dysplastic renal lesions during retroperitoneal laparoscopic nephrectomy in children. From March 2003 to March 2005, two boys and four girls with a mean age of 5 years underwent retroperitoneal laparoscopic nephrectomy under C-arm fluoroscopic guidance. The indications for laparoscopic renal surgery were ectopic ureter with dysplastic kidney (N = 3), hypertensive nephropathy (N = 1), and dysplastic kidney secondary to reflux nephropathy (N = 2). All operations were completed with no necessity for conversion to open surgery. Small dysplastic kidneys were easily located using C-arm fluoroscopy, and retroperitoneal laparoscopic nephrectomy was then performed. One patient required open contralateral reimplantation after laparoscopic nephrectomy because of high-grade vesicoureteral reflux. The mean operative time was 139 minutes (range 71-210 minutes). Blood loss was minimal, and no transfusion was required. There were no intraoperative or postoperative complications other than a peritoneal injury in one patient, which caused no subsequent major problem. The mean postoperative hospital stay was 3.8 days, and all children returned to normal activity within 3 to 6 days. This is the first report to our knowledge of retroperitoneal laparoscopic renal surgery under C-arm fluoroscopic guidance. This approach allowed quick and easy location of small ectopic kidneys prior to retroperitoneal laparoscopic nephrectomy and was found to be very useful for the treatment of small dysplastic renal lesions in children.

Spontaneous Rupture of the Left Common Iliac Vein: Management with Surgical Repair and Endovascular Stent

We report here on a case of spontaneous rupture of the left common iliac vein that was diagnosed preoperatively with computed tomography (CT), and the patient was successfully treated with surgery and stent placement. A 60-year-old woman was referred to our emergency room because of sudden left lower abdominal pain and swelling of the left lower extremity. CT revealed a huge retroperitoneal hematoma and extrinsic compression of the left common iliac vein with acute thrombosis of the deep veins of the left lower extremity. Venous patch angioplasty was performed at the site of spontaneous rupture. After performing thrombectomy with using a Forgaty catheter, a stent was placed at the occluded segment of the left common iliac vein under C-arm fluoroscopic guidance. The follow-up CT scans taken at 10 days and 8 months after the initial examination demonstrated a venous stent with preserved luminal patency and the striking resolution of the deep vein thrombosis of the left lower extremity.

Quadriparesis following cervical epidural steroid injections: case report and review of the literature

Background context Cervical epidural steroid injections are frequently used in the conservative management of neck pain, cervical radiculitis, and cervical radiculopathy. Between 64–76% of patients who receive injections report subjective pain improvement. Injections are usually well-tolerated with only mild, transient side effects, although a few case reports of patients with adverse effects do appear in the literature. Some clinicians have expressed concerns about epidural injections above the C7-T1 level, and in the use of methylprednisolone epidurally; as yet, neither is a consensus viewpoint. Purpose This case report describes severe adverse effects (quadriplegia and respiratory arrest) associated with an epidural injection into the C6-C7 space. Although the patient's symptoms improved somewhat with supportive care, quadriparesis appears irreversible. No reports of quadriparesis after cervical epidural injection were found in the literature, although other adverse effects have been reported. Study design/setting The patient was injected by a fellowship-trained pain management specialist in an outpatient surgicenter using C-arm fluoroscopic guidance. Immediately he experienced respiratory arrest with quadriplegia. He was intubated and transferred to the hospital, then transferred again to Christiana Health Care Services. Methods The patient was hospitalized, treated with steroid protocol within 8 hours, and followed clinically for 6 months. Results Magnetic resonance imaging within 6 hours of the injury and 6 months later showed no significant findings aside from lordosis (40° angle) of the cervical spine at the C6-C7 level. Conclusion Although evidence is not conclusive, this patient may have suffered a vascular event from a cervical epidural injection.