Sebastian Mafeld

Reactive lymphoid hyperplasia of the liver and pancreas. A report of two cases and a comprehensive review of the literature.

BACKGROUND Reactive lymphoid hyperplasia (RLH) is a rare non-neoplastic extranodal pathology with exceedingly rare occurrence in the liver and pancreas. We present two cases of hepatic RLH, one which had coinciding pancreatic involvement. To the best of our knowledge, concomitant hepatic and pancreatic RLH has not been previously reported. We also present a comprehensive review of the literature on hepatic and pancreatic RLH. METHODS An extensive literature search for all published reports on hepatic or pancreatic RLH was conducted. Data on clinical, radiographic and histopathological features were extracted in addition to therapeutic options and outcomes. RESULTS Forty-two hepatic and three pancreatic cases of RLH were described in the literature. The mean age of hepatic cases was 58 years, with a male-to-female ratio of above 1:7. Almost 25% of cases were associated with internal malignancy. Four hepatic cases were managed through active observation. The remainder (84%) underwent surgical resection. Due to their small number, no meaningful analysis could be made on the pancreatic cases. No recurrences were identified in any of the reported cases. CONCLUSION RLH should be considered in the diagnosis of hepatic nodules where biopsies fail to demonstrate malignant cells. Confirmed RLH lesions should be managed by active observation. Investigation and treatment of any potential source of lymphoid reactivity should be undertaken. More reports on pancreatic RLH need to be studied prior to drawing any useful recommendations on its management.

Renal denervation for treatment-resistant hypertension

Hypertension is a major public health concern that is increasing in prevalence. Lifestyle and pharmacological management are not always sufficient to control blood pressure and treatment-resistant hypertension is a recognized clinical challenge. Renal sympathetic denervation (RSD) represents a new frontier in the treatment of resistant hypertension. Results from the Symplicity HTN-1 and HTN-2 trials have demonstrated evidence that suggests RSD can safely reduce blood pressure in patients with this condition. More research is needed to verify these data, clarify unanswered questions and assess future applications of RSD. This review provides a detailed overview on the history of hypertension, treatment-resistant hypertension, the rationale behind RSD, current evidence and potential future applications of RSD. An overview of current and upcoming RSD devices is also included.

The role of simulation in the development of endovascular surgical skills

Endovascular trainees in the National Health Service still largely rely on the apprentice-apprenticeship model from the late 19th century. As the scope for endovascular therapy increases, due to the rapid innovation, evolution and refinement of technology, so too do patients’ therapeutic options. This climate has also opened the door for more novel training adjuncts, to address the gaps that exist in our current endovascular training curriculum. The aim of this paper is to present a succinct overview of endovascular simulation, synthesizing the trials and research behind this rapidly evolving training as well as highlighting areas where further research is required. The authors searched MEDLINE and EMBASE for relevant manuscripts on all aspects of endovascular simulation training. A comprehensive Google search was also undertaken to look for any relevant information on endovascular training courses available and any unpublished work that had been presented at relevant scientific meetings. Papers were categorized into the four models: synthetic, animal, virtual reality and human cadaver, and separate searches for evidence of skill transfer were also undertaken. Authors of novel research projects were contacted for further details of unpublished work and permission granted to report such findings in this manuscript.

Can the R.E.N.A.L Nephrometry Score Preoperatively Predict Postoperative Clinical Outcomes in Patients Undergoing Open and Laparoscopic Partial Nephrectomy

Aim: We evaluate whether the preoperative R.E.N.A.L Nephrometry Score (RNS) can predict the postoperative outcomes in patients undergoing either an open or laparoscopic partial nephrectomy. Patients and Methods: We retrospectively calculated the RNS of 128 patients who underwent either an open partial nephrectomy (OPN) (n = 38) or laparoscopic partial nephrectomy (LPN) (n = 90) between 2003 and 2011. Patients were categorized into low, moderate or high complexity groups based on RNSs. Intra-operative warm ischemic time (WIT), peri-operative surgical outcomes using the Clavien-Dindo classification, postoperative histology, positive surgical margin rates were correlated to the RNS. Results: The RNS was associated with the length of the WIT in OPN (low vs. moderate vs. high: 11.4 vs. 13.1 vs. 23.4 minutes, p = 0.025) and blood loss in LPN (low vs. moderate 319 vs. 498 ml, p = 0.009). The positive surgical margins were greater in high versus moderate RNS lesions (40 vs. 7.4%, p = 0.045). No differences were seen in complications, hospital stay or transfusion rates. The RNS was significantly higher in OPN versus LPN (7.45 vs. 6.2, p = 0.0002). Conclusion: An Increasing RNS was associated with increased WIT in OPN and blood loss in LPN, supporting RNS relationship to tumor complexity. A higher RNS in OPN indicate it may corroborate procedure choice. RNS should allow comparisons between treatment modalities for similar complexity lesions and with further research could aid stratification of individual risk preoperatively.

Developing cross‐specialty endovascular simulation training

Simulation is increasingly recognised as a valuable tool in training tomorrows doctors. This technology has the potential to improve patient safety and address some of the challenges posed by recent changes in doctors’ training, yet the uptake has been slow in the majority of institutions. In our own centre, we noted existing equipment was used infrequently. We sought to address this problem through the development of a 1–day training course in simulation (SIM) and basic interventional skills aimed at trainees from across different endovascular specialties.

Design of a Pulsatile Fresh Frozen Human Cadaver Circulation Model for Endovascular Training

BACKGROUND The objective of this project was to create a model capable of training endovascular skills using a freshly frozen human cadaver (HC). We present the results of our experience creating a cadaveric model for endovascular skills training. We undertook a unique cadaver laboratory-based research project. METHODS We favor a minimally invasive surgical technique with inflow into the right common carotid artery and outflow through the left common femoral and right superficial femoral arteries. Endovascular access was through the right common femoral artery. RESULTS Through this technique, the arch, thoracic, abdominal, and iliac vessels are all accessible. We perfuse the model through an open pulsatile flow circuit at varying rates to maximize angiographic image capture while minimizing cadaveric edema thus expanding the models longevity. CONCLUSIONS A fresh frozen pulsatile human cadaver training model is a feasible and credible training model that has exciting potential for endovascular skills training.

Physician-Modified Fenestrated Endografts for Managing the Ruptured or Symptomatic Aortic Aneurysm: Technique Overview and Clinical Outcomes

Purpose: Fenestrated endovascular aneurysm repair (FEVAR) grafts have a 10- to 12-week manufacturing time and are generally not available for emergency cases of symptomatic or ruptured aortic aneurysm. In the absence of other alternatives, conventional off-the-shelf stent grafts can be modified by trained operators to treat these complex cases. The aim of this study is to present a single-center experience of physician-modified FEVAR. Methods: A retrospective review was performed of all physician-modified FEVAR identified from the hospital endovascular database at a single tertiary referral center between September 1996 and September 2017. Results: Eight cases of urgent or emergency endovascular aneurysm repair (EVAR) with physician-modified grafts were identified. Mean follow-up was 44 weeks (range: 5-106 weeks). Outcomes for all implanted grafts (7/8 cases) included 100% technical success, 14% rate of endoleak, no procedure-related complications, no adverse visceral events, 0% 30-day mortality and 100% 1-year target vessel patency, and freedom from aneurysm-related death. There was a 14% (1/7 cases) per patient reintervention rate. Conclusion: Modifying EVAR grafts is a highly technical process requiring meticulous planning and extensive elective experience with FEVAR. The current series demonstrates that physician modification of endografts for urgent or emergency abdominal aortic aneurysm repair is feasible and a safe alternative to open surgical aneurysm repair.

Percutaneous perirenal thrombin injection for the treatment of acute hemorrhage after renal biopsy

Percutaneous renal biopsy is a valuable diagnostic approach. While commonly safe, it is not without risk and the most feared vascular complications include hemorrhage, pseudoaneurysm, and arteriovenous fistula formation. We report a case of acute hemorrhage after renal biopsy that was immediately identified by ultrasonography and successfully treated with percutaneous perirenal thrombin injection. This technique may prove a useful addition to the armamentarium of any operator performing renal biopsies.

Intrarenal arteriovenous shunts in kidney transplants demonstrated by contrast-enhanced ultrasound

The kidney can undergo several hemodynamic changes in response to physiological stressful conditions. Arteriovenous (AV) shunting is an example where renal blood flow is redistributed away from the cortex toward the metabolically vulnerable medulla. Identification of this phenomenon is important as it may reflect underlying pathology. Despite evidence of renal AV shunting, its existence has been questioned. To our knowledge, this case series demonstrates for the first time the presence of renal AV shunting using contrast enhanced ultrasound.

Evolving role of positron emission tomography (PET) in urological malignancy

We present a review on the increasing indications for the use of positron emission tomography (PET) in uro‐oncology. In this review we describe the details of the different types of PET scans, indications for requesting PET scans in specific urological malignancy and the interpretation of the results.