Mittul Gulati

Use of MR imaging to determine preservation of the neurovascular bundles at robotic-assisted laparoscopic prostatectomy.

PURPOSE To determine whether findings at preoperative endorectal coil magnetic resonance (MR) imaging influence the decision to preserve neurovascular bundles and the extent of surgical margins in robotic-assisted laparoscopic prostatectomy (RALP). MATERIALS AND METHODS This study was approved by the investigational review board and was compliant with the HIPAA; the requirement to obtain informed consent was waived. The authors prospectively evaluated 104 consecutive men with biopsy-proved prostate cancer who underwent preoperative endorectal coil MR imaging of the prostate and subsequent RALP. MR imaging was performed at 1.5 T between January 2004 and April 2008 and included T2-weighted imaging (n = 104), diffusion-weighted imaging (n = 88), dynamic contrast-enhanced imaging (n = 51), and MR spectroscopy (n = 91). One surgeon determined the planned preoperative extent of resection bilaterally on the basis of clinical information and then again after review of the final MR imaging report. The differences in the surgical plan before and after review of the MR imaging report were determined and compared with the actual surgical and pathologic results by using logistic regression analysis. Continuous and ranked variables underwent Pearson and Spearman analysis. RESULTS After review of MR imaging results, the initial surgical plan was changed in 28 of the 104 patients (27%); the surgical plan was changed to a nerve-sparing technique in 17 of the 28 patients (61%) and to a non-nerve-sparing technique in 11 (39%). Seven of the 104 patients (6.7%) had positive surgical margins. In patients whose surgical plan was changed to a nerve-sparing technique, there were no positive margins on the side of the prostate with a change in treatment plan. CONCLUSION Preoperative prostate MR imaging data changed the decision to use a nerve-sparing technique during RALP in 27% of patients in this series.

Spontaneous Intracerebral Hemorrhage Due to Coagulation Disorders

Although intracranial hemorrhage accounts for approximately 10 to 15% of all cases of stroke, it is associated with a high mortality rate. Bleeding disorders account for a small but significant risk factor associated with intracranial hemorrhage. In conditions such as hemophilia and acute leukemia associated with thrombocytopenia, massive intracranial hemorrhage is often the cause of death. The authors present a comprehensive review of both the physiology of hemostasis and the pathophysiology underlying spontaneous ICH due to coagulation disorders. These disorders are divided into acquired conditions, including iatrogenic and neoplastic coagulopathies, and congenital problems, including hemophilia and rarer diseases. The authors also discuss clinical features, diagnosis, and management of intracranial hemorrhage resulting from these bleeding disorders.

Spinal cord mapping as an adjunct for resection of intramedullary tumors: Surgical technique with case illustrations

OBJECTIVE Resection of intramedullary spinal cord tumors may result in transient or permanent neurological deficits. Intraoperative somatosensory evoked potentials (SSEPs) and motor evoked potentials are commonly used to limit complications. We used both antidromically elicited SSEPs for planning the myelotomy site and direct mapping of spinal cord tracts during tumor resection to reduce the risk of neurological deficits and increase the extent of tumor resection. METHODS In two patients, 3 and 12 years of age, with tumors of the thoracic and cervical spinal cord, respectively, antidromically elicited SSEPs were evoked by stimulation of the dorsal columns and were recorded with subdermal electrodes placed at the medial malleoli bilaterally. Intramedullary spinal cord mapping was performed by stimulating the resection cavity with a handheld Ojemann stimulator (Radionics, Burlington, MA). In addition to visual observation, subdermal needle electrodes inserted into the abductor pollicis brevis-flexor digiti minimi manus, tibialis anterior-gastrocnemius, and abductor halluces-abductor digiti minimi pedis muscles bilaterally recorded responses that identified motor pathways. RESULTS The midline of the spinal cord was anatomically identified by visualizing branches of the dorsal medullary vein penetrating the median sulcus. Antidromic responses were obtained by stimulation at 1-mm intervals on either side of the midline, and the region where no response was elicited was selected for the myelotomy. The anatomic and electrical midlines did not precisely overlap. Stimulation of abnormal tissue within the tumor did not elicit electromyographic activity. Approaching the periphery of the tumor, stimulation at 1 mA elicited an electromyographic response before normal spinal cord was visualized. Restimulation at lower currents by use of 0.25-mA increments identified the descending motor tracts adjacent to the tumor. After tumor resection, the tracts were restimulated to confirm functional integrity. Both patients were discharged within 2 weeks of surgery with minimal neurological deficits. CONCLUSION Antidromically elicited SSEPs were important in determining the midline of a distorted cord for placement of the myelotomy incision. Mapping spinal cord motor tracts with direct spinal cord stimulation and electromyographic recording facilitated the extent of surgical resection.

Clinical Outcome in Children Undergoing Tethered Cord Release Utilizing Intraoperative Neurophysiological Monitoring

Release of tethered spinal cord by sectioning of the filum terminale carries a risk of injuring neighboring motor and sensory nerve roots involved in bowel and bladder control. Therefore, intraoperative neurophysiological monitoring techniques have been developed to prevent neurological complications postoperatively. We performed a retrospective chart review of 63 patients who had undergone tethered cord release. We excluded adult patients, those lost to follow-up and patients with either a myelomeningocele and/or lipoma. This limited our study to 25 pediatric patients, aged 4 months to 12 years, who underwent tethered cord release for either a thickened filum terminale and/or a low-lying conus. For intraoperative monitoring, we utilized electrical stimulation of the filum terminale, lumbosacral nerve roots and electromyography recordings. Ventral nerve roots were identified and their electrical thresholds obtained. The mean was 0.32 V, the mode 0.1 V and the range 0.05– 1.0 V. These values were compared to electrical thresholds obtained by stimulation of the filum terminale. The mean was 26.1 V, the mode 20.0 V and the range 8–100 V. In over 70% of patients, muscle activation via the filum required 100 times the voltage needed to activate a motor root. This motor root to filum threshold of 1:100 was useful in identifying the filum. Clinical outcome showed no significant worsening with respect to bowel and bladder control or pain and motor indices. Significant bowel and bladder improvement was seen in 4 out of 25 patients, motor improvement in 9 out of 25 patients and improvement of pain in 4 out of 25 patients. Three patients developed postoperative urinary tract infections, but no cerebrospinal fluid leaks or pseudomeningoceles were encountered. These results suggest that patients with a thickened filum or low-lying conus can safely undergo tethered cord release. Intraoperative neurophysiological monitoring provides a helpful adjunct to distinguish nerve roots from the filum. A ratio, rather than an absolute number, is beneficial in distinguishing motor roots from the filum and eliminates variability due to patients’ individual differences in electrical thresholds.

Failure of Sacral Nerve Stimulation Due to Migration of Tined Lead

PURPOSE Stimulation of the sacral nerves is a commonly used treatment for frequency, urgency, urge incontinence, retention and other types of voiding dysfunction. Minimally invasive placement of a percutaneous permanent quadripolar tined lead into the sacral foramen has been described. No lead migration has been reported. We report on our experience with lead migration and the subsequent failure of InterStim in a large cohort of patients with a focus on possible diagnostic and salvage techniques. MATERIALS AND METHODS Between February 2002 and April 2005 tined lead electrodes were implanted in the S3 foramen in 235 patients using the InterStim system. Patients with a good response during the testing phase (greater than 50% improvement) underwent placement of an implantable pulse generator. Position was confirmed by radiographic evaluation intraoperatively. Sacral radiographs were obtained at the first postoperative visit, after IPG placement and whenever there was a change in symptomatic response. RESULTS There were 5 patients (2.1%) in whom treatment failed after a successful trial of stimulation due to lead migration. This was seen as early as 3 weeks and as late as 8 months. Migration of the lead occurred between first and second stage implantation in 1 of the 5 cases, and occurred after the second stage in 4 of 5. Anterior migration was noted in 4 patients and posterior migration was noted in 1. CONCLUSIONS Lead migration after placement of the tined lead can occur and thus sacral radiographs should be routinely used. This complication can be easily resolved without significant morbidity to the patient.

Transperineal Prostate Biopsy After Abdominoperineal Resection

PURPOSE Prostate cancer evaluation in men who have undergone abdominoperineal resection poses a challenge for urologists. Diagnosis and staging methods are limited because as access to the prostate via digital rectal examination is not possible. Prostate specific antigen (PSA) has been used to screen for malignancy in this population. However, the conventional diagnostic technique with transrectal ultrasound guided biopsies cannot be used. Transperineal ultrasound and biopsy have been described to evaluate the prostate in this setting. We report our experience with transperineal ultrasound biopsy for evaluating the prostate in patients with elevated PSA who have previously undergone abdominoperineal resection. MATERIALS AND METHODS We reviewed the records of 28 patients treated at 2 institutions. All patients had a history of abdominoperineal resection and subsequent transperineal ultrasound guided prostate biopsy for evaluating elevated PSA. Mean serum PSA in this population was 22 ng./ml. (median 9.5, range 4.1 to 237). Abdominoperineal resection was done in 16 patients (57%) for colorectal cancer, in 11 (39%) for ulcerative colitis and in 1 (4%) for familial polyposis coli. Average time since resection was 14 years (range 1 to 33). Five patients had previously undergone radiation therapy as part of treatment for colorectal cancer before transperineal ultrasound biopsy. RESULTS Of the 28 biopsies performed 23 revealed prostate cancer, 2 revealed prostatitis and 3 were benign. Average Gleason grade was 6.6 (range 3 to 9). Of the 23 patients with prostate cancer 22 were treated with androgen deprivation therapy (7), prostatectomy (8), external beam (6) and high dose (1) radiation therapy. Of the 8 patients who underwent prostatectomy pathological stage was T2 in 3 and T3 in 4, while pathological findings were not determined in 1 patient in whom the prostate was removed in pieces. CONCLUSIONS In patients with a history of abdominoperineal resection and elevated PSA transperineal ultrasound guided biopsy of the prostate can provide an accurate tissue diagnosis.

Laparoscopic radical nephrectomy for suspected renal cell carcinoma in dialysis-dependent patients

OBJECTIVES To characterize the treatment and outcomes of laparoscopic nephrectomy for suspected renal cancer in patients with dialysis-dependent renal failure. Laparoscopic nephrectomy is currently an accepted modality in the treatment of renal cell carcinoma in many patients. However, the indications for the minimally invasive approach in patients with renal dysfunction are unclear. End-stage renal disease has multiple manifestations associated with increased operative morbidity that are potentially amplified during laparoscopy. METHODS We reviewed our single-center experience for performing laparoscopic nephrectomy in patients with renal failure. Of patients receiving dialysis and having a kidney removed laparoscopically, 7 underwent the operation for suspected renal carcinoma because of a solid mass on imaging. The preoperative, intraoperative, and postoperative considerations were reviewed. RESULTS Of the 7 patients, 5 (71%) underwent successful removal of the kidney by laparoscopy. The amount of blood loss (120 mL) and the median time to discharge after surgery (3 days) were comparable to published data and our experience in patients with normal renal function; however, the operative time (mean 294 minutes) was longer. No recurrences had been detected at the last follow-up examination (median 21 months, range 18 to 51). Despite meticulous attention to perioperative and anesthetic considerations, two complications were observed-ileus and necrotizing fasciitis of the flank. CONCLUSIONS Pure laparoscopic nephrectomy for renal malignancy is feasible in patients with end-stage renal failure. However, this population is at increased risk of complications, despite maintaining the advantages of reduced blood loss and shorter hospitalization. The decision to proceed with laparoscopy and the selection of the specific surgical approach (transperitoneal or retroperitoneal) should be based on both surgeon experience and patient factors. In addition, careful preoperative preparation and intraoperative anesthetic management are crucial.

Contrast-enhanced ultrasound (CEUS) of cystic and solid renal lesions: a review

Incidentally detected renal lesions have traditionally undergone imaging characterization by contrast-enhanced computer tomography (CECT) or magnetic resonance imaging. Contrast-enhanced ultrasound (CEUS) of renal lesions is a relatively novel, but increasingly utilized, diagnostic modality. CEUS has advantages over CECT and MRI including unmatched temporal resolution due to continuous real-time imaging, lack of nephrotoxicity, and potential cost savings. CEUS has been most thoroughly evaluated in workup of complex cystic renal lesions, where it has been proposed as a replacement for CECT. Using CEUS to differentiate benign from malignant solid renal lesions has also been studied, but has proven difficult due to overlapping imaging features. Monitoring minimally invasive treatments of renal masses is an emerging application of CEUS. An additional promising area is quantitative analysis of renal masses using CEUS. This review discusses the scientific literature on renal CEUS, with an emphasis on imaging features differentiating various cystic and solid renal lesions.

Quantitative assessment of solid renal masses by contrast-enhanced ultrasound with time–intensity curves: how we do it

AbstractPurpose To discuss the evaluation of the enhancement curve over time of the major renal cell carcinoma (RCC) subtypes, oncocytoma, and lipid-poor angiomyolipoma, to aid in the preoperative differentiation of these entities. Differentiation of these lesions is important, given the different prognoses of the subtypes, as well as the desire to avoid resecting benign lesions.MethodsWe discuss findings from CT, MR, and US, but with a special emphasis on contrast-enhanced ultrasound (CEUS). CEUS technique is described, as well as time–intensity curve analysis.ResultsExamples of each of the major RCC subtypes (clear cell, papillary, and chromophobe) are shown, as well as examples of oncocytoma and lipid-poor angiomyolipoma. For each lesion, the time–intensity curve of enhancement on CEUS is reviewed, and correlated with the enhancement curve over time reported for multiphase CT and MR.ConclusionsPreoperative differentiation of the most common solid renal masses is important, and the time–intensity curves of these lesions show some distinguishing features that can aid in this differentiation. The use of CEUS is increasing, and as a modality it is especially well suited to the evaluation of the time–intensity curve.

Thrombosis of a spinal arteriovenous malformation after hemorrhage: case report.

BACKGROUND Thrombosis of cerebral arteriovenous malformations (AVM) and spinal dural arteriovenous fistulas following hemorrhage rarely have been reported. Rarer still is thrombosis of spinal AVMs following hemorrhage. CASE DESCRIPTION A 6-year-old boy presented with sudden low back and sciatic pain, bilateral leg weakness, and an intramedullary spinal cord hematoma. Spinal angiography demonstrated dilated feeding arteries without shunting, and no intervention was performed. Over time, these enlarged arteries reduced in caliber, and the patient recovered fully. CONCLUSIONS The rarity of spinal AVMs and AVM thrombosis make their coincidence in this case unique. Although surgical intervention would have enabled definitive diagnosis of the spinal AVM, it is not mandatory in the absence of arteriovenous shunting. What is mandatory, however, is continued angiographic surveillance, particularly in pediatric patients.