Chris Derham

Incomplete cellular depopulation may explain the high failure rate of bovine ureteric grafts

The aim was to assess the results of a decellularized bovine ureter graft (SynerGraft®) for complex venous access.

Tissue Engineering Small-Diameter Vascular Grafts: Preparation of a Biocompatible Porcine Ureteric Scaffold

This study aimed to investigate a biocompatible, biomechanically functional, small-diameter (<6 mm) scaffold for tissue engineering a vascular graft using acellular porcine ureters. Porcine ureters were decellularized and sterilized using sequential treatment with hypotonic Tris buffer, sodium dodecyl sulphate 0.1% w/v (plus proteinase inhibitors), nuclease solution (RNase and DNase), and peracetic acid. The scaffold was compared with fresh ureter according to histology, immunocytochemistry, quantitative determination of alpha-galactosyl (alpha-Gal), and biochemistry. The biomechanical properties of the scaffold were compared with those of fresh ureters and human saphenous vein. The biocompatibility of decellularized ureters was assessed using in vitro contact and extract cytotoxicity tests. The in vivo biocompatibility was investigated using a mouse model. The histioarchitecture of the acellular ureteric scaffolds was preserved with some loss of basement membrane proteins while showing no evidence of cellularity. There was no evidence of residual alpha-Gal epitope present in acellular ureter. The ultimate tensile strength, compliance, and burst pressures of the acellular ureters were not compromised, compared with fresh tissues (p > 0.05), and the results compared favorably with fresh human saphenous vein samples (p > 0.05). The decellularized scaffolds were shown to be biocompatible with porcine smooth muscle and endothelial cells in vitro. One month after subcutaneous implantation in mice, explants were analyzed immunohistochemically using anti-CD3, Factor VIII, F4/80 (macrophage), and alpha-smooth muscle actin antibodies. The fresh tissue controls had a significantly thicker capsule (of inflammatory cells and fibrous tissue) than decellularized implants (p < 0.05). Decellularized explants were infiltrated with a combination of fibroblast-like cells and macrophages, indicating a healthy repair process. This study has demonstrated the potential of acellular porcine ureteric scaffolds in tissue engineering small-diameter living vascular grafts.

Iatrogenic Limb Ischemia Caused by Angiography Closure Devices

Described are 2 cases of lower limb ischemia that resulted after deployment of 2 different arterial closure devices. One patient presented acutely with lower limb ischemia after an Angio-Seal (St Jude Medical, Minnetonka, Minn) device deployed at the conclusion of cerebral artery aneurysm embolization. The second patient, who underwent angioplasty for aortic recoarctation, presented with claudication 1 week after deployment of the Perclose (Perclose, Redwood City, Calif) device. The use of such devices can result in significant complications, and cardiologists, interventional radiologists, and vascular surgeons are advised to have a high index of suspicion for such complications and work in close conjunction to provide prompt and adequate treatment.

Randomized clinical trial of the effects of methylprednisolone on renal function after major vascular surgery

Perioperative renal dysfunction following abdominal aortic aneurysm (AAA) repair is multifactorial and may involve hypotension, hypoxia and ischaemia–reperfusion injury. Studies of cardiac and hepatic transplant surgery have demonstrated beneficial effects on renal function of high‐dose methylprednisolone administered before surgery.

Frontal sinus mucocele in association with fibrous dysplasia: review and report of two cases

We present two paediatric cases of fibrous dysplasia (FD) who presented to the craniofacial neurosurgical clinic with ophthalmological symptoms associated with sinus mucoceles. The first patient presented with a history of orbital cellulitis and an increasing bony swelling around the orbit associated with proptosis. Radiological imaging revealed monostotic FD associated with an obstructive mucocele in the frontal sinus with extension into the orbit. The second patient presented with recurrent conjunctivitis, painful proptosis, rhinitis and a bony peri-orbital swelling. Both patients had histological diagnoses of frontal mucoceles invading the orbit in association with FD. They both underwent frontal craniotomies and excision of the mucocele/fibrous dysplastic complex. In summary, mucocele development is an unusual complication of FD, likely to occur secondary to occlusion of the sinus drainage system. Orbital involvement may lead to visual disturbance caused by pressure effects. A multi-disciplinary approach including maxillofacial surgeons, plastic surgeons and neurosurgeons is advocated.

Multiple cranial neuropathy as the initial presentation of metastatic prostate adenocarcinoma: case report and review of literature

The skull base is an atypical metastatic site for prostate carcinoma. It is usually encountered late in the disease process in patients with known advanced disease. However, skull base involvement causing cranial nerve palsies may rarely be the presenting sign of prostate carcinoma. Such patients may present to a number of specialties including neurosurgery and can pose a diagnostic challenge in the absence of lower urinary tract symptoms. Here, we describe an unusual case of prostate adenocarcinoma presenting as a central skull base tumour with multiple cranial neuropathy.

Delayed sciatic neuropathy after distal semimembranosus muscle rupture associated with tethering of the sciatic nerve by a rare distal muscular branch.

Hamstring rupture usually occurs in professional athletes, but is rarely associated with sciatic neuropathy. Proximal hamstring rupture is much more often reported than distal rupture. Entrapment of the sciatic nerve from perineural scarring and muscle fibrosis is responsible for late neurologic sequelae of injury to the hamstring muscles. There is currently no literature reporting the incidence of acute or delayed sciatic neuralgia after proximal hamstring muscle rupture. The association between distal hamstring rupture and sciatic nerve injury is extremely rare. A few cases of isolated rupture of the distal semimembranosus tendon complex have been reported recently, but without neurological sequelae. We present the first case of distal semimembranosus muscle rupture with delayed sciatic neuropathy and explain its unusual cause other than perineural scarring.