Nabeel Sarwani

The analgesic efficacy of pre-operative bilateral erector spinae plane (ESP) blocks in patients having ventral hernia repair.

Laparoscopic ventral hernia repair is an operation associated with significant postoperative pain, and regional anaesthetic techniques are of potential benefit. The erector spinae plane (ESP) block performed at the level of the T5 transverse process has recently been described for thoracic surgery, and we hypothesised that performing the ESP block at a lower vertebral level would provide effective abdominal analgesia. We performed pre‐operative bilateral ESP blocks with 20–30 ml ropivacaine 0.5% at the level of the T7 transverse process in four patients undergoing laparoscopic ventral hernia repair. Median (range) 24‐h opioid consumption was 18.7 mg (0.0–43.0 mg) oral morphine. The highest and lowest median (range) pain scores in the first 24 h were 3.5 (3.0–5.0) and 2.5 (0.0–3.0) on an 11‐point numerical rating scale. We also performed the block in a fresh cadaver and assessed the extent of injectate spread using computerised tomography. There was radiographic evidence of spread extending cranially to the upper thoracic levels and caudally as far as the L2–L3 transverse processes. We conclude that the ESP block is a promising regional anaesthetic technique for laparoscopic ventral hernia repair and other abdominal surgery when performed at the level of the T7 transverse process. Its advantages are the ability to block both supra‐umbilical and infra‐umbilical dermatomes with a single‐level injection and its relative simplicity.

Pseudoenhancement of renal cysts: influence of lesion size, lesion location, slice thickness, and number of MDCT detectors.

OBJECTIVE The purpose of this study was to determine the effect of renal cyst size and location on pseudoenhancement in human subjects. MATERIALS AND METHODS Simple renal cysts obtained with 16-, 40-, and 64-MDCT scanners were analyzed for the presence of pseudoenhancement. Cyst size, location, and attenuation in the unenhanced and nephrographic phases were recorded. Pseudoenhancement was defined as an attenuation increase of 10 HU or more on nephrographic phase compared with unenhanced images. RESULTS The pseudoenhancement rate was 22% (51/233). There was a statistically significant increase in the pseudoenhancement rate of lesions smaller than 10 mm (38/233) compared with those 10 mm and larger (13/233) (odds ratio, 6.4; p<0.0001). Twelve of 62 cysts measuring 10-14 mm exhibited pseudoenhancement. There was a statistically significant increase in the pseudoenhancement rate of central (39/53) compared with peripheral (12/51) cysts (odds ratio, 2.7; p<0.0001). The pseudoenhancement rates for the 16-, 40-, and 64-MDCT scanners were 20%, 19%, and 26% with no statistically significant difference between them. CONCLUSION Pseudoenhancement of renal cysts significantly correlates with size smaller than 1 cm and central location. Although pseudoenhancement increases with larger numbers of detectors, the correlation was not statistically significant. Cysts in the 1- to 1.5-cm range have a 19% likelihood of pseudoenhancement.

Use of a simulation laboratory to train radiology residents in the management of acute radiologic emergencies.

OBJECTIVE Simulation laboratories use realistic clinical scenarios to train physicians in a controlled environment, especially in potentially life-threatening complications that require prompt management. The objective of our study was to develop a comprehensive program using the simulation laboratory to train radiology residents in the management of acute radiologic emergencies. MATERIALS AND METHODS All radiology residents attended a dedicated simulation laboratory course lasting 3 hours, divided over two sessions. Training included basic patient management skills, management of a tension pneumothorax, massive hemorrhage, and contrast agent reactions. Participants were presented with 20 multiple-choice questions before and after the course. Pre- and posttest results were analyzed, and the McNemar test was used to compare correct responses by individual question. RESULTS Twenty-six radiology residents attended the class. The average pre- and posttest scores and the average difference between the scores for all residents were 13.8, 17.1, and 3.3, respectively (p < 0.0001). Incorrect answers on the pretest examination that were subsequently answered correctly concerned administration of epinephrine for severe reactions, management of a tension pneumothorax, oxygen therapy, ECG placement, cardiopulmonary resuscitation technique, and where to stand during a code situation. Persistent incorrect answers concerned vasovagal reactions and emergency telephone numbers at an off-site imaging center. CONCLUSION Simulation laboratories can be used to teach crisis management and crisis resource management for radiology residents and should be part of the education toolbox. Defined objectives lead to a comprehensive course dealing with the management of acute radiologic emergencies. Such programs can improve the role of radiologists as members of the health care team.

Lymphoepithelial Cysts of the Pancreas. Can Preoperative Imaging Distinguish This Benign Lesion from Malignant or Pre-Malignant Cystic Pancreatic Lesions?

CONTEXT Lymphoepithelial cysts of the pancreas are rare true benign cystic tumors of the pancreas of uncertain etiology. Cystic neoplasms of the pancreas present a significant diagnostic dilemma in differentiating benign from premalignant or malignant variants. Since the first description of lymphoepithelial cysts in 1985, 109 cases have been reported in the literature. We describe 6 cases of this rare tumor, the preoperative imaging results, and a review the literature. PATIENTS Five males and one female ranging in age from 47 to 76 years underwent resection for lymphoepithelial cysts. Five patients presented with abdominal pain related to the lesion and in one patient the lesion was discovered incidentally. Four patients had elevated serum CA 19-9 levels. Pre-operative imaging with a CT scan and MRI of the abdomen typically revealed a well defined hypodense mass with Hounsfield units (HU) in the range of 15 to 20. One patient had papillary projections into the lesion. The mean size was 3.3 cm (ranging from 1.8 cm to 4 cm). All lesions were exophytic off the pancreatic parenchyma (1 cyst was located in the head of the pancreas, 2 were in the body, and 3 were in the tail region). Pre-operative EUS-guided/CT-guided needle aspiration, when performed, was not diagnostic. All patients underwent resection (one pancreaticoduodenectomy, five left pancreatectomies) to remove these cystic neoplasms. Pathology revealed a cyst lined by non-dysplastic squamous cells surrounded by sheets of benign lymphocytes. No evidence of malignancy was found. CONCLUSION Lymphoepithelial cysts of the pancreas are rare and are characteristically seen in men. While a hypodense mass (less than 20 HU) with papillary projections should be considered suspicious for lymphoepithelial cyst, a definitive diagnosis cannot be made solely based on preoperative imaging. EUS-guided biopsy coupled with biochemical/tumor marker studies are increasingly being used as a diagnostic tool to help differentiate between the various types of cystic pancreatic neoplasms. Imaging findings of lymphoepithelial cysts are non-specific and hence surgical resection is often required to rule out the presence of a malignant or pre-malignant cystic pancreatic lesion. In true lymphoepithelial cysts, malignant transformation is not seen and patients who have these cysts are not at increased risk of developing a pancreatic malignancy.

Circulating tumor cells are associated with diffuse spread in stage IV colorectal cancer patients.

Background Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States when combining both genders. Circulating tumor cells (CTCs) are a prognostic marker for stage IV CRC patients. We hypothesized that CTC quantity varies among stage IV CRC populations. Methods Blood (7.5 ml) was prospectively collected from 90 stage IV CRC patients. EpCAM+ CTCs were analyzed with the FDA-approved CellSearch® system. CRC tumors were immunohistochemically stained for EpCAM expression. Imaging and clinicopathological data were collected. Statistical analysis was performed using correlation analysis, Kruskal–Wallis, Fisher exact, and log-rank test. Results CTCs were detectable in 36/90 (40%) patients. Diffuse CRC metastases were associated with the highest CTC prevalence (24/40 [60%]), in contrast to limited lung (2/19 [11%]) or liver (10/31 [32%]) metastases (P = 0.027). The overall mean CTC number was 2.0 (range 0–56.3). The mean CTC number in patients with diffuse metastases was significantly higher (3.7 [SEM ± 1.7, range 0–56.3]) than with limited lung metastases (0.1 [± 0.1; range 0–1]) or liver metastases (0.9 [± 0.3, range 0–7.0]) (P = 0.001). CRC tumors were consistently expressing EpCAM. CTC numbers did not correlate with serum CEA levels or other routine clinical parameters (P = N.S.). Patients with diffuse metastases had the poorest overall survival (P = 0.0042). Conclusions CRC patients with diffuse metastases have the highest number of CTCs, in contrast to limited metastases to the liver or lungs. Future studies should correlate CTCs with recurrence patterns in patients with resected CRC lung or liver metastases to investigate whether CTCs represent micrometastatic disease causing early relapses.

A radiologic and anatomic assessment of injectate spread following transmuscular quadratus lumborum block in cadavers

We performed bilateral transmuscular quadratus lumborum blocks in six cadavers using iodinated contrast and methylene blue. Computed tomography imaging was performed in four cadavers and anatomical dissection was completed in five. This demonstrated spread to the lumbar paravertebral space in 63% of specimens, laterally to the transversus abdominis muscle in 50% and caudally to the anterior superior iliac spine in 63% of specimens. There was no radiographic evidence of spread to the thoracic paravertebral space. Anatomical dissection revealed dye staining of the upper branches of the lumbar plexus and the psoas major muscle in 70% of specimens. Further clinical studies are required to confirm if the quadratus lumborum block might be a suitable alternative to lumbar plexus block.

Clinico-pathological correlation of serial measurement of circulating tumor cells in 24 metastatic colorectal cancer patients receiving chemotherapy reveals interpatient heterogeneity correlated with CEA levels but independent of KRAS and BRAF mutation

Background: The Veridex CellSearch is an FDA-approved technology for enumerating circulating tumor cells in blood samples of metastatic colorectal cancer mCRC) patients and has prognostic value. It is important to understand how counts of circulating tumor cells (CTCs), which are advocated to be tools for “liquid biopsy” of tumors, correlate with clinical and pathologic variables of significance in these patients. In this study, we have attempted to make such correlations along with evaluating how CTC counts change during the course of chemotherapy. Patients and methods: Following an IRB-approved protocol, blood samples were collected from 24 patients with mCRC along with relevant clinico-pathological data. Blood was collected at defined time-points both prior to as well as during the course of treatment with combination chemotherapy, and CTC counts were enumerated from7.5 ml of blood. Results: Seventeen out of 24 patients with mCRC showed a CTC count of 2 or less cells in 7.5 ml of blood at base-line assessment before chemotherapy while 7 patients showed 3 or more cells in 7.5 ml of blood at that point. A correlation was found between high carcino-embryonic antigen (CEA) levels and high CTC counts (P = 0.018) although it was also found that some patients had elevated CTCs without an elevated CEA. No correlation with the time interval between detection of primary tumor and appearance of secondary (metastatic) tumor(s) was found. CTC counts did not correlate with the presence of lung or liver metastases, i.e. a number of mCRC patients with lung or liver metastases had a count of zero CTCs at baseline. We also noted no correlation between CTC number and the status of KRAS or BRAF mutation. CTC counts dropped immediately after the start of chemotherapy in 11 out of 21 patients, and also reduced from the baseline at the end of chemotherapy in 5 out of 10 patients. Six of 7 patients who started with 3 or more CTCs in 7.5 ml at baseline also showed a final CTC reduction at the end of the therapy assessment. Conclusions: Analysis of circulating tumor cells may be of use in monitoring response to therapy in mCRC, either in combination with CEA monitoring or alone when CTCs are elevated but CEA level is not.

Therapeutic approach guided by genetic alteration: use of MTOR inhibitor in renal medullary carcinoma with loss of PTEN expression.

Renal Medullary Cancer (RMC) is a rare and aggressive type of renal cell cancer that presents predominantly in patients with sickle cell hemoglobinopathies, and is typically metastatic at the time of presentation. Although platinum based chemotherapeutic regimens have recently emerged as the best option for producing a clinically significant response as reported in various case series, the response is far from satisfactory, as most RMC patients still succumb to their disease within a year of diagnosis. There is currently no standard of care for treatment of this disease. We report, to our knowledge, the first case of RMC where in molecular characterization of the tumor was used to guide therapy. In our patient, molecular analysis identified a decreased expression of Ribonucleotide Reductase M1(RRM1) and phosphatase and tensin homolog (PTEN). Based on these results of PTEN deficiency, we started our patient on everolimus (an MTOR inhibitor) maintenance after treating him with an induction chemotherapy regimen of Paclitaxel-Cisplatin-Gemcitabine (PCG). His tumor responded to induction therapy and he went into complete remission and remained in remission for 7 months. He is now alive about 14 months from his diagnosis and is asymptomatic with minimal disease. The rarity of RMC makes it very difficult to do any meaningful clinical trials in this group of patients. The overall prognosis for RMC remains very poor and knowledge about driver mutations may help in guiding therapy to improve survival in this select group of patients, where there is dearth of available therapies.

Contradictory KRAS mutation test results in a patient with metastatic colon cancer: A clinical dilemma in the era of personalized medicine

The KRAS oncogene is mutated in 40‒50% of colorectal cancers and confers resistance to EGFR-targeted therapy. In the clinic, agents such as cetuximab or panitumumab target the EGFR receptor for therapeutic benefit. Cetuximab was approved by the FDA in 2012 as first-line therapy for KRAS mutation-negative (wild-type), EGFR-expressing metastatic colorectal cancer, in combination with FOLFIRI (5-fluorouracil, irinotecan, leucovorin). Herein we report a case of metastatic colon cancer with conflicting testing results for the KRAS oncogene from two different reference laboratories. The discordant reports complicated the decision-making process regarding the administration of targeted anti-EGFR personalized therapy. As the second test result was wild-type from the same original pathological specimen, the patient was treated with cetuximab-containing combination chemotherapy and appeared to have a response after prior disease progression. It is unclear whether the observed response was fully due to regression of wild-type KRAS-containing tumor or any component of antibody-dependent cellular cytotoxicity to a heterogeneous tumor in this patient.

FOLFIRI plus dulanermin (rhApo2L/TRAIL) in a patient with BRAF-mutant metastatic colon cancer

Colorectal cancer patients with BRAF-mutant tumors have a more aggressive, rapidly progressing disease that is in critical need of novel therapeutic approaches. Indeed, whereas the median overall survival (OS) of colorectal cancer (CRC) patients receiving standard-of-care therapy is approximately two years or more if their tumors express wild-type BRAF and wild-type KRAS, median OS is less than twelve months with tumors expressing V600E-mutant BRAF and wild-type KRAS. Pro-apoptotic receptor agonists are a class of biologic agents under development to induce tumor-specific apoptosis and are being combined with classical chemotherapy or targeted agents in clinical trials. Herein, we present the case of a patient with bulky V600E-mutant BRAF hepatic flexure colon carcinoma, treated initially with FOLFOX plus bevacizumab neoadjuvant therapy and surgery. The patient had a rapid tumor relapse with metastatic disease to the liver and lung, and was enrolled in a phase 1b open-label clinical study, where he received the FOLFIRI regimen in combination with the pro-apoptotic receptor agonist dulanermin (rhApo2L/TRAIL). The patient maintained stable disease through 25 doses administered every two weeks before his disease progressed. After coming off study, the patient underwent surgical debulking and received intraperitoneal hyperthermic chemotherapy. He subsequently relapsed and was treated with FOLFIRI plus cetuximab. At the time of this report, the patient remains on active treatment. It is unclear what effect dulanermin may have had on the course of his disease, but it is noteworthy that the patient remained on FOLFIRI plus dulanermin therapy for a period that exceeded the median OS for patients with advanced, aggressive BRAF-mutant CRC. It is also noteworthy that at the time of this report the patients overall survival since diagnosis has exceeded 30 months, which is beyond what is generally observed even for patients with CRC harboring wild-type BRAF and wild-type KRAS.