Treatment Failure After Percutaneous Radiofrequency Ablation for Nonsurgical Candidates With Pulmonary Metastases From Colorectal Carcinoma

Background This study critically evaluated the local and overall treatment failure rates after percutaneous radiofrequency ablation (RFA) of pulmonary metastases from colorectal carcinoma. Methods Fifty-five nonsurgical candidates underwent RFA of colorectal pulmonary metastases. The primary end points of this study were local progression-free survival (PFS) and overall PFS. Univariate and multivariate analyses were performed to identify significant prognostic parameters for local and overall PFS. Results The local recurrence rate was 38%. For local PFS, univariate analysis demonstrated that the largest size of lung metastasis, the location of lung metastases, the post-RFA carcinoembryonic antigen level at 1 month, and the post-RFA carcinoembryonic antigen level at 3 months were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm and a post-RFA carcinoembryonic antigen level of >5 ng/mL at 1 month were independently associated with a reduced local PFS. The overall recurrence rate was 66%. For overall PFS, univariate analysis demonstrated that sex and the largest size of lung metastasis were significant prognostic indicators. In multivariate analysis, a largest size of lung metastasis of >3 cm was independently associated with a reduced overall PFS. Conclusions RFA of colorectal pulmonary metastases may have a useful role in local disease control for nonsurgical candidates, but its efficacy in patients with a lung metastasis of >3 cm is limited.     

Questionnaire study of neuromonitoring availability and usage for spine surgery

STUDY DESIGN: Questionnaire study presented to practicing spine surgeons. OBJECTIVE: To evaluate surgeon preference and availability of selected electrophysiologic neuromonitoring for different spine surgeries. SUMMARY OF BACKGROUND DATA: Maximizing the safety of spinal procedures and limiting potential iatrogenic neurologic injury has made intraoperative neuromonitoring an attractive option. METHODS: We distributed a questionnaire to 180 orthopedic spine surgeons and neurosurgeons at a clinically oriented spine meeting asking surgeon preference and availability of various types of intraoperative neuromonitoring modalities for different types of surgical procedures. Demographic data were also gathered. RESULTS: Somatosensory evoked potentials (SSEPs) were the most available neuromonitoring modality, followed by electromyographies and motor-evoked potentials. In both anterior and posterior cervical surgery, SSEPs were the most preferred modality. MEPs were frequently preferred in myelopathic cervical cases. Almost 70% preferred some neuromonitoring for anterior thoracic/thoracolumbar cases and 55% for posterior thoracic/thoracolumbar cases. Surgeon satisfaction was related to the number of available neuromonitoring modalities. No significant differences were found between orthopedist and neurosurgeon preferences. Fellowship-trained surgeons were more likely to use neuromonitoring for specific indications. CONCLUSIONS: SSEPs remains the most widely available and preferred type of neuromonitoring for spine surgeons. The type of case and neurologic status of patient (eg, presence of myelopathy) affects these choices. Surgeons were more satisfied with greater neuromonitoring availability, and were more likely to use neuromonitoring if they had a fellowship background.     

Surgical revascularization versus endovascular therapy for chronic mesenteric ischemia: a comparative experience

INTRODUCTION: Endovascular therapy (percutaneous transluminal angioplasty [PTA] with stenting) has been increasingly applied in patients with chronic mesenteric ischemia (CMI) to avoid morbidities associated with open repair (OR). The purpose of this study was to compare outcomes of PTA/Stent vs OR in patients with symptomatic CMI. METHODS: During the interval of January 1991 to December 2005, 80 consecutive patients presenting with symptomatic CMI underwent elective revascularization. Patients with acute mesenteric ischemia or those with mesenteric revascularization performed as part of complex aneurysm repair were excluded. PTA/Stent (with stenting in 87%) was the initial procedure in 31 patients (42 vessels). OR was performed in 49 patients (88 vessels) and consisted of bypass grafting in 31 (63%), transaortic endarterectomy in 7 (14%), patch angioplasty in 4 (8%), or combined in 7 (15%). Mean follow-up was 15 months in the PTA/Stent group and 42 months in the OR cohort. Study end points included perioperative morbidity, mortality, late survival (Kaplan-Meier), and symptomatic and radiographic recurrence. RESULTS: Baseline comorbidities, with the exception of heart disease (P=.025) and serum albumin<3.5 g/dL (P=.025), were similar between PTA/Stent and OR patients. The PTA/Stent group had fewer vessels revascularized (1.5 vs 1.8 vessels, P=.001). Hospital length of stay was less for the PTA/Stent group (5.6 vs 16.7 days, P=.001). No difference was noted in in-hospital major morbidity (4/31 vs 2/49, P=.23) or mortality (1/31 vs 1/49, P=.74). Actuarial survival at 2 years was similar between the groups (88% PTA/Stent vs 74% OR, P=.28). There was no difference in the incidence of symptomatic (7/31 [23%] vs 11/49 [22%], P=.98) or radiographic recurrence (10/31 [32%] vs 18/49 [37%], P=.40) between the two groups. Radiographic primary patency (58% vs 90%, P=.001) and primary assisted patency (65% vs 96%, P<.001) at 1 year were lower in the PTA/Stent group compared with OR. Five (16%) of 31 PTA/Stent patients compared with 11 (22%) of 49 OR patients required a second intervention on at least one index vessel at any time (P=.49). CONCLUSIONS: Symptomatic recurrence requiring reintervention is common (overall 16/80 [20%]) after open and endovascular treatment for CMI. PTA/Stent was associated with decreased primary patency, primary assisted patency, and the need for earlier reintervention. In-hospital mortality or major morbidity were similar in patients undergoing PTA/Stent and OR. These findings suggest that OR and PTA/Stent should be applied selectively in CMI patients in accordance with individual patient anatomic and comorbidity considerations.     

Symptomatic rectocele: what are the indications for repair?

Background

The surgical indications for symptomatic rectocele are undefined, and surgery has high recurrence rates. We implemented magnetic resonance imaging defecography (MRID) to determine if utilizing strict inclusion criteria for rectocele repair improves outcomes.

Methods

Patients with obstructive defecation syndrome (ODS) who underwent dynamic MRID were evaluated. Indications for surgical repair were defecation requiring manual assistance and the following MRID results: anterior defect >2 cm, incomplete evacuation, and the absence of perineal descent. Primary outcomes were the change in quality of life (QOL) scores and recurrence.

Results

From 2006 to 2013, 143 patients who presented with ODS underwent MRID. Seventeen patients met the criteria for repair. Recurrence was low (5.8%) with a median follow-up of 23 months, QOL scores improved from 57.3 to 76.5 (P = .041).

Conclusions

A minority of patients (12%) with ODS met the above criteria for rectocele repair. Patients who underwent repair had a significant improvement in QOL and low recurrence rate.     

Percutaneous Imaging–Guided Radiofrequency Ablation in Patients With Colorectal Pulmonary Metastases: 1-Year Follow-Up

Background: We assessed the safety and evidence of efficacy of radiofrequency ablation (RFA) for colorectal lung metastases with follow-up to 1 year.Methods: Twenty-three patients had percutaneous RFA for 52 colorectal pulmonary metastases under fluoro-computed tomography (CT). Patients received intravenous conscious sedation and local analgesia with routine hospitalization and monitoring for 24 hours after RFA. Patients had CT scanning at 1 month and then every 3 months, with serum carcinoembryonic antigen assessment monthly and every 3 months.Results: All ablations were technically successful. Tumor diameter ranged from .3 to 4.2 cm. Pneumothorax occurred in 43% (10 of 23) of patients. Six patients required intercostal chest drain placement. Six patients had a second RFA, four for new lesions and two for re-treatment of a previously treated lesion. The median admission was 2.0 days (range, 1–9 days). The median follow-up was 428 days (range, 173–829 days); data are reported to 1 year in this article. Five patients died at 5, 6, 8, 8, and 12 months after RFA from extrapulmonary (n = 1) or widespread (n = 4) disease. One patient developed a malignant pleural effusion at 6 months after RFA. Cavitation was seen in nine treated lesions (17%); all resolved with scar tissue contraction by 12 months. Eighteen patients with CT scan follow-up at 1 year have 40 lesions classified as disappeared (n = 17), decreased (n = 5), stable/same size (n = 4), or increased (n = 14).Conclusions: Percutaneous imaging–guided RFA of multiple colorectal pulmonary metastases is a minimally invasive treatment option with modest morbidity. A significant proportion of patients show good evidence of successful local control at 1 year.     

Stiffness of prosthetic nucleus determines stiffness of reconstructed lumbar calf disc.

BACKGROUND CONTEXT: Currently, artificial spinal discs require transection or partial removal of the annulus fibrosis in order to excise the nucleus and implant a prosthetic nucleus or implant a total disc device, respectively. Preservation of the annulus for prosthetic disc replacement maintains the function of the annulus and may improve annulus load sharing with the prosthesis. PURPOSE: To quantify the biomechanical characteristics of an annular sparing intervertebral prosthetic disc (IPD) in a lumbar calf spine model. The aim of the study was to determine whether altering the stiffness of the elastic component of this unique prosthesis would correspond to changes of the overall reconstructed disc. STUDY DESIGN/SETTING: A biomechanical study was conducted in vitro using cadaveric calf spines such that each specimen served as its own control. Investigations were performed at the Minneapolis Medical Research Foundation, Orthopaedic Biomechanics Laboratory. METHODS: Six L45 or L56 motion segments (from which the posterior elements had been removed) were studied in axial compression, sagittal and lateral bending and torsion. These load states were applied to the intact, denucleated and prosthetically reconstructed disc using four IPDs of differing stiffness. RESULTS: Load-displacement testing demonstrated that stiffer IPDs resulted in a decreased range of motion and neutral zone, and greater stiffness of the reconstructed disc. Disc reconstruction with the stiffest IPD approximated the behavior of the intact disc. CONCLUSIONS: The overall biomechanical characteristics of a reconstructed disc are related to the stiffness of a nucleus prosthesis. The similarities in the mechanical behavior of reconstructed and intact discs suggest that additional feasibility studies for the annulus-sparing IPD are warranted.     

Advanced imaging in stone management

PURPOSE OF REVIEW: Stone disease continues to plague humankind. Recent innovations in minimally invasive surgery, however, have decreased morbidity for the treatment of lithiasis, once only amenable to open surgical techniques. These advances in stone management have also been paralleled in the radiographic armamentarium. Herein, we describe the evolution of initial radiographic workup for urolithiasis, from abdominal radiograph to three-dimensional computed tomography and some of the novel applications thereof. RECENT FINDINGS: Previously, abdominal radiography was the only modality available for the visualization of calculi. Subsequently, the development of intravenous contrast aided in evaluating renal function, detecting the presence and location of obstruction, and in identifying filling defects. Most recently, prospective randomized trials have demonstrated improved sensitivity and specificity using noncontrast helical computed tomography rather than intravenous pyelogram with regard to the initial evaluation of acute flank pain. Further attempts to lower the overall radiation dose without compromising efficacy have also been introduced. Currently, the volume of calculus disease can be better quantified and somewhat qualified from three-dimensional computer software, thereby optimizing stone management. SUMMARY: Considerable progress has been made using minimally invasive techniques in the treatment of nephrolithiasis. Furthermore, advances in radiographic computer hard- and software applications allow for a rapid acquisition time and improved image quality without sacrificing diagnostic accuracy. In time, it is likely that the combination of these enhanced imaging modalities will lead to an improvement in stone localization, fragmentation and stone-free rates.     

The effect of treatment strategy on stone comminution efficiency in shock wave lithotripsy

PURPOSE: The comminution of kidney stones in shock wave lithotripsy (SWL) is a dose dependent process caused primarily by the combination of 2 fundamental mechanisms, namely stress waves and cavitation. The effect of treatment strategy with emphasis on enhancing the effect of stress waves or cavitation on stone comminution in SWL was investigated. Because vascular injury in SWL is also dose dependent, optimization of the treatment strategy may produce improved stone comminution with decreased tissue injury in SWL. MATERIALS AND METHODS: Using an in vitro experiment system that mimics stone fragmentation in the renal pelvis spherical BegoStone (Bego USA, Smithfield, Rhode Island) phantoms (diameter 10 mm) were exposed to 1,500 shocks at a pulse repetition rate of 1 Hz in an unmodified HM-3 lithotripter (Dornier Medical Systems, Kennesaw, Georgia). The 3 treatment strategies used were increasing output voltage from 18 to 20 and then to 22 kV every 500 shocks with emphasis on enhancing the effect of cavitation on medium fragments (2 to 4 mm) at the final treatment stage, decreasing output voltage from 22 to 20 and then to 18 kV every 500 shocks with emphasis on enhancing the effect of stress waves on large fragments (greater than 4 mm) at the initial treatment stage and maintaining a constant output voltage at 20 kV, as typically used in SWL procedures. Following shock wave exposure the size distribution of fragments was determined by the sequential sieving method. In addition, pressure waveforms at lithotripter focus (F2) produced at different output settings were measured using a fiber optic probe hydrophone. RESULTS: The rate of stone comminution in SWL varied significantly in a dose dependent manner depending on the treatment strategies used. Specifically the comminution efficiencies produced by the 3 strategies after the initial 500 shocks were 30.7%, 59% and 41.9%, respectively. After 1,000 shocks the corresponding comminution efficiencies became similar (60.2%, 68.1% and 66.4%, respectively) with no statistically significant differences (p = 0.08). After 1,500 shocks the final comminution efficiency produced by the first strategy was 88.7%, which was better than the corresponding values of 81.2% and 83.5%, respectively, for the other 2 strategies. The difference between the final comminution efficiency of the first and second strategies was statistically significant (p = 0.005). CONCLUSIONS: Progressive increase in lithotripter output voltage can produce the best overall stone comminution in vitro.     

Comprehensive MR imaging in the preoperative evaluation of living donor candidates for laparoscopic nephrectomy: initial experience

PURPOSE: To evaluate the accuracy of magnetic resonance (MR) imaging in the preoperative evaluation of potential living renal donors who are candidates for laparoscopic nephrectomy. MATERIALS AND METHODS: Twenty-eight donor candidates who underwent subsequent laparoscopic nephrectomy were examined by using a torso phased-array coil at 1.5 T. Gadolinium-enhanced MR angiograms, MR venograms, and MR urograms were obtained in all patients by using an interpolated three-dimensional T1-weighted spoiled gradient-echo sequence (3.4-6.8/1.2-2.3 [repetition time msec/echo time msec], 25 degrees -40 degrees flip angle). Interpretation of the MR images was used to assess the arterial, venous, and ureteral anatomy, as well as parenchymal masses and scarring, and findings were compared with the surgical findings in all patients. Statistical evaluation was performed, with the surgical findings as the reference standard. RESULTS: At MR imaging, 31 of 32 renal arteries and one of three early-branching arteries were identified correctly. The correct venous anatomy was identified in 23 of 28 patients, including a single left renal vein anterior to the aorta (n = 16), retroaortic left renal vein (n = 2), circumaortic left renal vein (n = 2), and single right renal vein (n = 3). A single collecting system in all harvested kidneys was identified correctly with MR urography. Overall, MR imaging correctly depicted vascular, ureteral, and parenchymal anatomy in 21 of 28 patients. Twenty-seven of 28 patients underwent successful laparoscopic donor nephrectomy on the basis of the MR findings. One procedure was converted to open nephrectomy on the basis of complex venous anatomy not prospectively identified on the MR images. The sensitivity and positive predictive value of MR imaging in correctly determining the combined vascular, ureteral, and parenchymal anatomy in the harvested kidney were 75% (21 of 28) and 95% (21 of 22), respectively. CONCLUSION: Comprehensive gadolinium-enhanced MR imaging can depict the vascular anatomy, collecting system, and renal parenchyma preoperatively in patients who are candidates for laparoscopic living-donor nephrectomy.