Diagnosis and Management of Pelvic Venous Disorders: AJR Expert Panel Narrative Review

Pelvic venous disorders (PeVD), previously known by various imprecise terms including pelvic congestion syndrome, have historically been underdiagnosed as a cause of chronic pelvic pain (CPP), a significant health problem associated with reduced quality of life. However, progress in the field has helped to provide heightened clarity with respect to definitions relating to PeVD, and evolution in algorithms for PeVD workup and treatment has been accompanied by new insights into the causes of a pelvic venous reservoir and associated symptoms. Ovarian and pelvic vein embolization, as well as endovascular stenting of common iliac vein compression, should be considered as management options for PeVD. Both treatments have been shown to be safe and effective for patients with CPP of venous origin, regardless of age. Current therapeutic protocols for PeVD exhibit significant heterogeneity owing to limited prospective randomized data and evolving understanding of the factors driving successful outcomes; forthcoming clinical trials are anticipated to improve understanding of CPP of venous origin as well as algorithms for PeVD management. This Expert Panel Narrative Review provides a contemporary update relating to PeVD, summarizing the entity's current classification, diagnostic workup, endovascular treatments, management of persistent or recurrent symptoms, and future research directions.

Single-Center Review of Celiac Plexus/Retrocrural Splanchnic Nerve Block for Non-Cancer Related Pain

RATIONALE AND OBJECTIVES

Celiac plexus and retrocrural splanchnic nerve (CP/RSN) blocks are widely used for cancer-related abdominal pain, but there is limited literature on their efficacy for non-cancer related pain. Our aim was to determine the indications and effectiveness of CT-guided CP/RSN blocks performed on patients with abdominal pain from non-cancer related sources.

MATERIALS AND METHODS

CT-guided CP/RSN blocks for non-cancer related abdominal pain from 2011-2020 were retrospectively reviewed for patient demographics, procedure details, duration of pain relief, and complications. Effective blocks were defined as patient-reported pain relief or decrease in opioid use lasting 2 or more days for temporary blocks and 14 or more days for permanent blocks.

RESULTS

Of 72 CT-guided CP/RSN blocks for non-cancer related abdominal pain, 48 (67%) were effective for a mean of 51 days (median 14, range 2-700). Of the 18 permanent blocks, 9 (50%) were effective for a mean of 111 days (median 90, range 14-390). Of the 54 temporary blocks, 39 (72%) were effective for a mean of 37 days (median 9, range 2-700). Indications included postural orthostatic tachycardia syndrome/dysautonomia (77% effective, 20/26), pancreatitis (86% effective, 12/14), postsurgical pain (62% effective, 8/13), median arcuate ligament syndrome (70% effective, 7/10), chronic pain syndrome (20% effective, 1/5), gastroparesis (80% effective, 4/5), and renal cystic disease (33% effective, 1/3). For postural orthostatic tachycardia syndrome /dysautonomia, pancreatitis, post-surgical pain, and MALS, there were no statistically significant differences in effectiveness between celiac vs. splanchnic blocks in groups matched by indication and intended duration (temporary/permanent).

CONCLUSIONS

CT-guided CP/RSN blocks can effectively manage non-cancer related abdominal pain, though there is discrepancy in efficacy between temporary and permanent blocks.

Liquid Biopsy in Gastrointestinal Cancers

Liquid biopsy is the sampling of any biological fluid in an effort to enrich and analyze a tumor's genetic material. Peripheral blood remains the most studied liquid biopsy material, with circulating tumor cells (CTC's) and circulating tumor DNA (ctDNA) allowing the examination and longitudinal monitoring of a tumors genetic landscape. With applications in cancer screening, prognostic stratification, therapy selection and disease surveillance, liquid biopsy represents an exciting new paradigm in the field of cancer diagnostics and offers a less invasive and more comprehensive alternative to conventional tissue biopsy. Here, we examine liquid biopsies in gastrointestinal cancers, specifically colorectal, gastric, and pancreatic cancers, with an emphasis on applications in diagnostics, prognostics and therapeutics.

Minimally Invasive Limited Ligation Endoluminal-Assisted Revision (MILLER): A Review of the Available Literature and Brief Overview of Alternate Therapies in Dialysis Associated Steal Syndrome

Dialysis associated steal syndrome (DASS) is a relatively rare but debilitating complication of arteriovenous fistulas. While mild symptoms can be observed, if severe symptoms are left untreated, DASS can result in ulcerations and limb threatening ischemia. High-flow with resultant heart failure is another documented complication following dialysis access procedures. Historically, open surgical procedures have been the mainstay of therapy for both DASS as well as high-flow. These procedures included ligation, open surgical banding, distal revascularization-interval ligation, revascularization using distal inflow, and proximal invasion of arterial inflow. While effective, open surgical procedures and general anesthesia are preferably avoided in this high-risk population. Minimally invasive limited ligation endoluminal-assisted revision (MILLER) offers both a precise as well as a minimally invasive approach to treating both dialysis associated steal syndrome as well as high-flow with resultant heart failure. MILLER is not ideal for all DASS patients, particularly those with low-flow fistulas. We aim to briefly describe the open surgical therapies as well as review both the technical aspects of the MILLER procedure and the available literature.

Degree of Left Renal Vein Compression Predicts Nutcracker Syndrome

Nutcracker syndrome (NS) refers to symptomatic compression of the left renal vein (LRV) between the abdominal aorta and superior mesenteric artery with potential symptoms including hematuria, proteinuria, left flank pain, and renal venous hypertension. No consensus diagnostic criteria exist to guide endovascular treatment. We aimed to evaluate the specificity of LRV compression to NS symptoms through a retrospective study including 33 NS and 103 control patients. The size of the patent lumen at point of compression and normal portions of the LRV were measured for all patients. Multiple logistic regression analyses (MLR) assessing impact of compression, body mass index (BMI), age, and gender on the likelihood of each symptom with NS were obtained. NS patients presented most commonly with abdominal pain (72.7%), followed by hematuria (57.6%), proteinuria (39.4%), and left flank pain (30.3%). These symptoms were more commonly seen than in the control group at 10.6, 11.7, 6.8, and 1.9%, respectively. The degree of LRV compression for NS was 74.5% and 25.2% for controls (p < 0.0001). Higher compression led to more hematuria (p < 0.0013), abdominal pain (p < 0.006), and more proteinuria (p < 0.002). Furthermore, the average BMI of NS patients was 21.4 and 27.2 for controls (p < 0.001) and a low BMI led to more abdominal pain (p < 0.005). These results demonstrate a strong correlation between the degree of LRV compression on imaging in diagnosing NS.

ACR Appropriateness Criteria® Radiologic Management of Uterine Leiomyomas

Uterine fibroids, also known as leiomyomas, are the most common benign tumor in women of reproductive age. When symptomatic, these patients can present with bleeding and/or bulk-related symptoms. Treatment options for symptomatic uterine leiomyomas include medical management, minimally invasive treatment such as uterine artery embolization, and surgical options, such as myomectomy. It is important to understand the role of these treatment options in various clinical scenarios so that appropriate consultation is performed. Furthermore, patients should be presented with the outcomes and complications of each of these treatment options. A summary of the data and clinical trials of the treatment options for symptomatic uterine leiomyomas is outlined in this article. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Multi-Detector Computed Tomography Imaging Techniques in Arterial Injuries

Cross-sectional imaging has become a critical aspect in the evaluation of arterial injuries. In particular, angiography using computed tomography (CT) is the imaging of choice. A variety of techniques and options are available when evaluating for arterial injuries. Techniques involve contrast bolus, various phases of contrast enhancement, multiplanar reconstruction, volume rendering, and maximum intensity projection. After the images are rendered, a variety of features may be seen that diagnose the injury. This article provides a general overview of the techniques, important findings, and pitfalls in cross sectional imaging of arterial imaging, particularly in relation to computed tomography. In addition, the future directions of computed tomography, including a few techniques in the process of development, is also discussed.

Colorectal-Vaginal Fistulas: Imaging and Novel Interventional Treatment Modalities

Colovaginal and/or rectovaginal fistulas cause significant and distressing symptoms, including vaginitis, passage of flatus/feces through the vagina, and painful skin excoriation. These fistulas can be a challenging condition to treat. Although most fistulas can be treated with surgical repair, for those patients who are not operative candidates, limited options remain. As minimally-invasive interventional techniques have evolved, the possibility of fistula occlusion has enriched the therapeutic armamentarium for the treatment of these complex patients. In order to offer optimal treatment options to these patients, it is important to understand the imaging and anatomical features which may appropriately guide the surgeon and/or interventional radiologist during pre-procedural planning.

ACR Appropriateness Criteria® Radiologic Management of Central Venous Access

Obtaining central venous access is one of the most commonly performed procedures in hospital settings. Multiple devices such as peripherally inserted central venous catheters, tunneled central venous catheters (eg, Hohn catheter, Hickman catheter, C. R. Bard, Inc, Salt Lake City UT), and implantable ports are available for this purpose. The device selected for central venous access depends on the clinical indication, duration of the treatment, and associated comorbidities. It is important for health care providers to familiarize themselves with the types of central venous catheters available, including information about their indications, contraindications, and potential complications, especially the management of catheters in the setting of catheter-related bloodstream infections. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Radiologic Management of Mesenteric Ischemia

Mesenteric vascular insufficiency is a serious medical condition that may lead to bowel infarction, morbidity, and mortality that may approach 50%. Recommended therapy for acute mesenteric ischemia includes aspiration embolectomy, transcatheter thrombolysis, and angioplasty with or without stenting for the treatment of underlying arterial stenosis. Nonocclusive mesenteric ischemia may respond to transarterial infusion of vasodilators such as nitroglycerin, papaverine, glucagon, and prostaglandin E1. Recommended therapy for chronic mesenteric ischemia includes angioplasty with or without stent placement and, if an endovascular approach is not possible, surgical bypass or endarterectomy. The diagnosis of median arcuate ligament syndrome is controversial, but surgical release may be appropriate depending on the clinical situation. Venous mesenteric ischemia may respond to systemic anticoagulation alone. Transhepatic or transjugular superior mesenteric vein catheterization and thrombolytic infusion can be offered depending on the severity of symptoms, condition of the patient, and response to systemic anticoagulation. Adjunct transjugular intrahepatic portosystemic shunt creation can be considered for outflow improvement. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

May-Thurner: diagnosis and endovascular management

Common left iliac vein compression, otherwise known as May-Thurner (MT), is an anatomical risk factor for lower extremity deep vein thrombosis (DVT). MT refers to chronic compression of the left iliac vein against the lumbar spine by the overlying right common iliac artery. The compression may be asymptomatic. The syndrome is a clinical spectrum of physical findings and history plus the lesion. It is characterized by the varying degrees of venous hypertension. This can be non-thrombotic, combined with acute DVT or post-thrombotic. Traditionally, acute DVT was treated with standard anticoagulation and sometimes, thrombectomy. However these measures do not address the underlying culprit lesion of mechanical compression. Furthermore, if managed only with anticoagulation, patients with residual thrombus are at risk for developing recurrent DVT or post-thrombotic syndrome (PTS). Both retrospective and prospective studies have shown that endovascular management should be the preferred approach to dissolve proximal thrombus and to also treat the underlying compression with endovascular stent placement.

Enterolith causing afferent loop obstruction: a case report and literature review

Enterolith formation is a rare cause of afferent limb obstruction following Billroth II gastrectomy and Roux-en-Y hepaticojejunostomy surgery. A case of ascending cholangitis caused by an enterolith incarcerated in the afferent loop of a 15-year-old Roux-en-Y hepaticojejunostomy was emergently decompressed under direct ultrasound guidance prior to surgery. This is the thirteenth reported case of an enterolith causing afferent loop obstruction. A discussion of our management approach and a review of the relevant literature are presented.

Atypical complications of gastric bypass surgery

Although gastric bypass surgery continues to grow in popularity for weight loss and weight maintenance in the morbidly obese, there has been little attention given to the imaging of complications associated with these surgeries. The purpose of our study is to demonstrate the variety of gastric bypass surgery complications that can be identified radiographically, with attention to the more unusual complications. This study was performed with institutional Internal Review Board approval. We performed a 5-year retrospective review of all patients who had undergone gastric bypass surgery, had complications of the surgery, and had studies performed in our department to image these complications. These studies consisted of contrast fluoroscopy and CT. We identified the more common complications of anastomotic stenoses and anastomotic leaks. We also identified six unusual complications as follow: (1) internal herniation through the small bowel mesentery, (2) internal herniation through the transverse mesocolon, (3) external herniation through the abdominal wall incision, (4) enterocutaneous fistulas, (5) antiperistaltic construction of the Roux-en-Y, and (6) incorrect anstomoses of the Roux limbs resulting in a Roux-en-O configuration. Our findings show that a thorough understanding of expected postoperative bowel configuration is essential in the evaluation of these patients. In addition, fluoroscopic evaluation should assess not only anatomy, but also motility.

Awareness in classical differential eyeblink conditioning in young and aging humans

The role of awareness and its impact on learning the conditioned eyeblink response was investigated in both trace and delay discrimination eyeblink conditioning in young and aging participants, in 4 paradigms: delay 750, delay 1,250, trace 500, and trace 1,000. Participants concurrently watched a silent movie about which they were questioned afterward. Acquisition in both the trace and delay discrimination task was correlated with awareness of conditioning stimulus contingencies, regardless of age. Age-dependent deficits were observed in trace discrimination but not in delay discrimination, with more severe deficits appearing at the longer trace interval. The percentage of aware participants was also found to be greater in the young population than in the aging population. These results indicate that awareness or knowledge of stimulus contingencies may be an important contributor to successful acquisition in higher order discrimination tasks.

Awareness in classical differential eyeblink conditioning in young and aging humans

The role of awareness and its impact on learning the conditioned eyeblink response was investigated in both trace and delay discrimination eyeblink conditioning in young and aging participants, in 4 paradigms: delay 750, delay 1,250, trace 500, and trace 1,000. Participants concurrently watched a silent movie about which they were questioned afterward. Acquisition in both the trace and delay discrimination task was correlated with awareness of conditioning stimulus contingencies, regardless of age. Age-dependent deficits were observed in trace discrimination but not in delay discrimination, with more severe deficits appearing at the longer trace interval. The percentage of aware participants was also found to be greater in the young population than in the aging population. These results indicate that awareness or knowledge of stimulus contingencies may be an important contributor to successful acquisition in higher order discrimination tasks.

Age-related effects on eyeblink conditioning in the F344 x BN F1 hybrid rat

Young, middle-aged, old, and senescent Fischer 344 x Brown Norway F1 hybrid rats were trained in either the trace or delay eyeblink conditioning task in order to investigate how aging affects associative learning and memory over the life span. Senescent rats at 34-35 months showed severe impairments in acquisition of the trace task with a 250 msec trace interval, which is hippocampally-dependent, and were mildly impaired in the simple delay eyeblink conditioning task. Middle aged animals, varying in age from 18-24 months, acquired the trace and delay eyeblink paradigms as well as young rats (6 months). However, at 28-29 months, approximately 50% of the old animals showed impairments in the trace 250 msec eyeblink task. Our results show that trace eyeblink conditioning is an age-sensitive task useful for studying the neural substrates underlying associative learning and memory in rats, as has been previously shown in humans and rabbits.

Trace eyeblink conditioning in the freely moving rat: optimizing the conditioning parameters

Trace eyeblink conditioning (EBC) parameters, with an airpuff unconditioned stimulus, were examined in male Fischer 344 X Brown Norway F1 rats. Integrated electromyographic activity from the upper eyelid was recorded. An 8-kHz tone was superior to white noise as a conditioning stimulus. Rats trained with 30 or 50 trials per session showed similar learning. Reversal of environmental lighting had no significant effect. Trace intervals of 0 and 250 ms yielded well-timed conditioned responses (CRs); intervals of 500 ms or more did not. These experiments provide parameters that reliably yield CRs and suggest limits on the temporal processing capabilities of the rat. EBC can thus be used as part of a comprehensive test battery for learning and memory in this species. Physiological recording and pharmacological manipulations may also be done easily. This combination of approaches should facilitate a more complete understanding of learning mechanisms and age-related memory impairments.

Trace eyeblink conditioning in the freely moving rat: optimizing the conditioning parameters

Trace eyeblink conditioning (EBC) parameters, with an airpuff unconditioned stimulus, were examined in male Fischer 344 X Brown Norway F1 rats. Integrated electromyographic activity from the upper eyelid was recorded. An 8-kHz tone was superior to white noise as a conditioning stimulus. Rats trained with 30 or 50 trials per session showed similar learning. Reversal of environmental lighting had no significant effect. Trace intervals of 0 and 250 ms yielded well-timed conditioned responses (CRs); intervals of 500 ms or more did not. These experiments provide parameters that reliably yield CRs and suggest limits on the temporal processing capabilities of the rat. EBC can thus be used as part of a comprehensive test battery for learning and memory in this species. Physiological recording and pharmacological manipulations may also be done easily. This combination of approaches should facilitate a more complete understanding of learning mechanisms and age-related memory impairments.