Rowland, C

Smoking is a major risk factor for failure of coronary artery bypass grafts (CABG). Experiments were designed to determine effects of transdermal nicotine, independent of smoking, on structure and function of CABG. Saphenous veins were placed as CABG in untreated dogs (control) or in dogs treated with transdermal nicotine (one 11-mg or two 22-mg patches/day) for 5 wk. Serum nicotine and plasma nitric oxide were measured. Grafts were removed and prepared for organ chamber studies and histology. Serum nicotine averaged 12.1 and 118.7 ng/ml in the 11 mg/day and 44 mg/day groups, respectively. Plasma nitric oxide was higher in dogs treated with 11 mg/day doses compared with controls. In organ chamber studies, endothelium-dependent relaxations to thrombin and A-23187 and endothelium-independent relaxations to nitric oxide were greatest in grafts from dogs treated with 11 mg/day doses. Intimal thickness of the grafts were similar among groups. However, staining for bone sialoprotein was increased in the media of grafts from the 11 mg/day treatment group. These data suggest that transdermal nicotine in doses comparable and double to those used for conventional smoking cessation treatment in humans does not adversely affect early patency of canine CABG up to 4 wk postoperatively. Transdermal nicotine, however, may increase production of and response to nitric oxide in bypass grafts.

Widespread applications of totally laparoscopic aortic reconstructions have been limited by the long cross-clamp time required to suture the aortic anastomosis despite improvement in instrumentation. The authors' hypothesis was that a “one-step anastomosis concept” using an intraluminal stapler would allow shorter cross-clamp time but similar patency and imperviousness as videoscopic suturing techniques. An intraluminal stapler (Endopath-ILS, Ethicon) with a modified anvil was used to perform videoscopic-assisted thoracic aorta-to-iliac artery bypass with a 21 mm by 8 mm polytetrafluoroethylene (PTFE) graft in 22 sheep through a minimally invasive approach using a 5 cm thoracotomy. The graft-to-iliac artery anastomoses were hand sutured through a flank incision. Twelve sheep were used to establish the technique and 10 subsequent animals constituted the study group. Aortic cross-clamp time, imperviousness, and need for additional sutures were recorded and compared to previously reported data using videoscopic suturing in pigs. Patency was assessed by comparing lower limb arterial pressures. Macroscopic and microscopic examinations of the anastomoses were performed at different time-points within the first 3 months. Videoscopic-assisted stapled anastomoses were also performed on atherosclerotic aortas of 3 human cadavers. Stapled anastomoses between the thoracic aorta and PTFE graft were completed in 8 of 10 animals. Two animals were euthanized after stapler failure and anastomotic bleeding. Sutures to strengthen the anastomosis had to be used in 4 cases. Mean aortic cross-clamp time in 8 successful cases was 4.3 ±2.9 minutes (range 2–11 minutes) and was significantly shorter than clamp time of videoscopic suturing technique (48.7 ±9.4 minutes, p<0.0001). Imperviousness was good or excellent in 4 animals and fair in 4 animals. All anastomoses were patent at the end of the procedure. Examination of the anastomosis of the 2 failed interventions showed medial aortic tear surrounding the anastomosis in 1 case and misfired staples in the other. No graft occlusion was noted during follow-up ranging from 0 to 12 weeks. At the time of harvest, no bleeding was noted after epinephrine and volume infusion to increase mean arterial pressure to 200 mm Hg for 15 minutes. Macroscopic examination of the anastomoses revealed adequate healing with circumferential stapling of the prosthesis to the aortic wall and no stenosis or thrombus except in 1 false aneurysm (1/7, 14%). Surface electron microscopy showed cells coverage of the anastomosis surface. When applied on human cadaver thoracic and abdominal aorta with atherosclerotic changes, clamping times of less than 5 minutes were achieved. However, imperviousness tested with saline was poor. An automatic stapling device allows performance of a graft-to-aorta anastomosis through a minimally invasive approach with shorter clamping time than a videoscopic suturing technique. However, the current technique of aortic stapling is unreliable and further improvements are needed.

Abstract Background Calciphylaxis is a rare, painful, life-threatening problem of cutaneous necrosis and refractory healing seen in patients with uraemia and secondary hyperparathyroidism. The pathogenesis involves abnormalities in calcium and phosphorus metabolism, and acute deposition of calcium in tissues. Methods The clinical course of 16 patients diagnosed with calciphylaxis at this institution from 1994 to 1998 was reviewed. Results Fourteen women and two men, with a mean age of 56 (range 39–70) years, presented with chronic renal disease of various causes, hyperparathyroidism and characteristic skin lesions. All patients underwent intensive medical therapy, including haemodialysis (n = 16), parathyroidectomy (PTX) (n = 7) and skin debridement of cutaneous lesions (n = 8). Mean preoperative serum values in surgical (PTX) versus non-surgical patients were: calcium 9·9 and 9·3 mg dl−1 (P = 0·25); phosphorus 5·8 and 4·9 mg dl−1 (P = 0·04); calcium–phosphorus product 61·6 and 45·2 (P = 0·03); and parathyroid hormone (PTH) 56·8 and 5·9 pmol l−1 (P = 0·0001) respectively. Mean postoperative values for calcium (8·7 mg dl−1), phosphorus (4·2 mg dl−1), calcium–phosphorus product (30·5) and PTH (4·0 pmol l−1) in surgical patients changed significantly (P &lt; 0·05). Median overall survival was 9·4 months with 15 patients now deceased. Median survival was 14·8 and 6·3 months for PTX versus no PTX (P = 0·22), 14·1 and 6·1 months for skin debridement versus no debridement (P = 0·08), 12·4 and 6·6 months for proximal versus distal skin lesions (P = 0·60), and 6·5 and 13·9 months for diabetic versus non-diabetic patients was (P = 0·11). Conclusion Calciphylaxis appears to have a female preponderance with a very dismal prognosis. A multidisciplinary approach using frequent haemodialysis to normalize serum calcium and phosphorus levels, and local debridement of skin lesions seems prudent. PTX cannot be recommended routinely in all such patients unless severe secondary hyperparathyroidism with poorly controlled metabolic disturbance mandates surgery. The exact indications for PTX for calciphylaxis remain unclear.

Abstract Background Primary sarcomas of the liver are extremely rare in adults. Optimal therapeutic approaches remain unclear. Methods Twenty consecutive adult patients who had surgical treatment for primary hepatic sarcomas were reviewed. Patient age ranged from 23 to 80 years. Other than one patient with primary hepatic angiosarcoma who had a history of thorium dioxide colloid (Thorotrast) exposure 23 years before diagnosis, no predisposing causes were apparent. Nineteen patients had hepatic resection and one patient had an orthotopic liver transplant. No patient received neoadjuvant chemotherapy or radiotherapy but radiotherapy was delivered intraoperatively in one patient. Results Leiomyosarcoma was the most common histological type of sarcoma diagnosed (five of 20 patients), followed by malignant solitary fibrous tumour (four) and epithelioid haemangioendothelioma (three). Fourteen tumours were high-grade sarcomas and six were low grade malignancies. Thirteen patients developed a recurrence. Distant metastases (ten patients) and intrahepatic recurrence (six) were the predominant sites of initial treatment failure. Six patients received salvage chemotherapy. Histological grade was the only factor significantly associated with overall patient survival (P = 0·03). With complete resection, patients with high-grade tumours had a 5-year survival rate of 18 (95 per cent confidence interval 5–62) per cent compared with 80 (52–100) per cent for patients with low-grade tumours. The 5-year survival rate for all 20 patients was 37 (20–60) per cent. Conclusion Surgical resection is the only effective therapy for primary hepatic sarcomas at present. Better adjuvant therapy is necessary, especially for high-grade malignancies, owing to the high failure rate with operation alone.