Wilfrido R. Castaneda

Surgical Treatment of Advanced-Stage Carcinoid Tumors: Lessons Learned

Objective:To evaluate clinical outcomes in a large group of advanced-stage carcinoid patients (stage IV) following multimodal surgical therapy. Summary Background Data:Patients with advanced-stage carcinoid have traditionally experienced poor 5-year survival (18%–30%). Few recent series have evaluated a large number of patients treated with aggressive surgical rescue therapy. Methods:This single-center retrospective review analyzes the records of 82 consecutive carcinoid patients treated by the same 2 surgeons, from August 1998 through August 2004 with a 3- to 72-month follow-up. Results:Surprisingly, one third of 26 (32%) patients were found to have intestinal obstructions; 10 being moribund at presentation. Mesenteric encasement with intestinal ischemia was successfully relieved in 10 of 12 cases. Five of eighty-two “terminal” patients were rendered free of macroscopic disease. Karnofsky performance scores improved from 65 to 85 (P < 0.0001). Two- and four-year survival for patients with no or unilateral liver metastases (n = 23) was 89%, while 2- and 4-year survival for patients with bilateral liver disease (n = 59) was 68% and 52% (P = 0.072), respectively. Conclusion:We think that all patients with advanced-stage carcinoid should be evaluated for possible multimodal surgical therapy. Primary tumors should be resected, even in the presence of distant metastases to prevent future intestinal obstruction. The “wait and see” method of management of this slow-growing cancer no longer has merit. We offer an algorithm for the surgical evaluation and management of these patients.

Comparison of thrombolytic therapy of lower-extremity acute, subacute, and chronic arterial occlusions

Our purpose was to study the effectiveness of thrombolytic therapy in treating acute, subacute, and chronic arterial occlusions in a multicenter retrospective study. Intraarterial urokinase infusion was performed in 235 patients for occluded native arteries. There were 70 (30%) with acute and 26 (5%) with subacute occlusions, and 141 (59%) with chronic symptoms for longer than 3 mo. Complete thrombolysis was achieved in 60 (86%) of the acute, 20 (77%) of the subacute, and 106 (75%) of the chronic occlusions. Adjunctive interventional procedures were performed as needed. Long-term follow-up revealed a primary patency of 87%, 85%, and 76% for the acute, subacute, and chronic occlusion groups, respectively. We conclude that the rate of complete thrombolysis of chronic occlusions proved slightly more efficient for acute and virtually the same for subacute occlusions. Long-term follow-up demonstrated a higher failure rate with chronic than with acute occlusions, probably due to worsened peripheral vascular runoff.

Treatment of Chronic Iliac Artery Occlusions with Guide Wire Recanalization and Primary Stent Placement

PURPOSE To evaluate the results of primary stent placement without initial thrombolysis in the treatment of iliac occlusions. MATERIALS AND METHODS During a 3-year period, 61 iliac artery occlusions were treated in 59 patients. The mean length of the occluded segment was 10 cm (range, 4-25 cm). The occluded arteries were treated with primary placement of self-expandable metallic stents. RESULTS Successful recanalization with primary stent placement was possible in 56 of 61 occlusions (92% technical success rate). Mean Doppler ankle/brachial index increased from 0.51 to 0.90 immediately after treatment and was 0.91 on the last follow-up (P < .05). Primary patency rate at 24 months was 73%, and secondary patency rate was 88%. Procedural complications included distal embolization (n = 4) and an episode of massive intra-abdominal bleeding. Three patients developed a hematoma at the puncture site that did not require additional therapy. Late complications included stent occlusion (n = 9) and significant stenosis related to intimal hyperplasia (n = 1). Mean follow-up period was 29 months (range, 7-55 months). CONCLUSION Primary stent placement is an effective therapeutic option for iliac artery occlusions.

Bifurcated Endoprosthesis for Treatment of Aortoiliac Occlusive Lesions

Purpose: To report our initial experience with a bifurcated endoprosthesis in the management of aortoiliac occlusive disease. Methods: From May 2001 to February 2004, 112 patients were referred to our institution for the management of aortoiliac disease. Among these, 5 (6%) patients (3 men; mean age 57.8 years) with severe ischemia owing to TASC C or D iliac occlusions were selected for endovascular treatment with a bifurcated stent-graft. An Excluder stent-graft was placed after preliminary recanalization (thrombolysis and/or balloon dilation) the day before. The patients were followed clinically and ultrasonographically every 3 months during the first year and semiannually thereafter. Results: Technical success was achieved in all patients. Endovascular aortoiliac bifurcation reconstruction restored iliac artery flow immediately in all cases. There were no procedurerelated complications. The mean ankle-brachial index (ABI) was significantly improved, from 0.66±0.04 before the procedure to 0.94±0.06 immediately after the procedure (p < 0.01). The aortoiliac reconstructions remained patent during the mean 17-month follow-up (range 3–36), and the ABIs were stable. There was no mortality or amputation required in this series. Conclusions: Endovascular placement of a bifurcated stent-graft appears to be technically feasible, effective, and safe in the management of aortoiliac occlusive disease.

An animal model of abdominal aortic aneurysm created with peritoneal patch: technique and initial results.

AbstractThe purpose of this study was to develop an abdominal aortic aneurysm model that more closely resembles the morphology of human aneurysms with potential for further growth of the sac. An infrarenal abdominal aortic aneurysm (AAA) model was created with a double-layered peritoneal patch in 27 domestic swine. The patch, measuring in average from 6 to 12 cm in length and from 2 to 3 cm in width, was sutured to the edge of an aortotomy. Pre- and postsurgical digital subtraction aortograms (DSA) were obtained to document the appearance and dimensions of the aneurysm. All animals were followed with DSA for up to 5 months. Laparoscopic examination enhanced by the use of laparoscopic ultrasound was also carried out in 2 animals to assess the aneurysm at 30 and 60 days following surgery. Histological examination was performed on 4 animals. All the animals that underwent the surgical creation of the AAA survived the surgical procedure. Postsurgical DSA demonstrated the presence of the AAA in all animals, defined as more than 50% increase in diameter. The aneurysmal mean diameter increased from the baseline of 10.27 ± 1.24 to 16.69 ± 2.29 mm immediately after surgery, to 27.6 ± 6.59 mm at 14 days, 32.45 ± 8.76 mm at 30 days (p < 0.01), and subsequently decreased to 25.98 ± 3.75 mm at 60 days. A total of 15 animals died of aneurysmal rupture that occurred more frequently in the long aneurysms (≥6 cm in length) than the short aneurysms (<6 cm in length) during the first 2 weeks after surgery (p < 0.05). No rupture occurred beyond 16 days after surgery. Four animals survived and underwent 60-day angiographic follow-up. Laparoscopic follow-up showed strong pulses, a reddish external appearance and undetectable suture lines on the aneurysmal wall. On pathology, the patches were well incorporated into the aortic wall, the luminal wall appeared almost completely endothelialized, and cellular and matrix proliferation were noted in the aneurysmal wall. A reproducible technique for the creation of an infrarenal AAA model was developed using a peritoneal patch in swine. The aneurysm model proved to have potential for further growth of the sac and a tendency to rupture. Because of the growth potential, this might be a better model than those with a noncompliant aneurysmal wall for the preclinical evaluation of stent-graft devices.

Can Labeled Single-Use Devices Be Reused? An Old Question in the New Era

REPROCESSING and reuse of medical single-use devices (SUDs) such as catheters and guide wires are gaining popularity as a result of the escalating cost of health care. A recent survey revealed that approximately 20%–30% of hospitals in the United States reprocess SUDs (1). The figures are likely underestimated because hospitals tend not to report their use of reprocessed SUDs. According to the United States General Accounting Office, substantial cost savings can be achieved by reprocessing SUDs because the cost of in-house reprocessing can be less than 10% of the cost of a new device and the cost of third-party reprocessing is approximately 50% of the cost of a new device (1). The legitimate questions here are: 1. Is it safe and economically sound to use reprocessed SUDs? 2. Are reprocessed SUDs as good as the original devices in terms of chemical and physical characteristics? 3. How should reprocessing be regulated to ensure public health? The answers to these questions depend on to whom they are addressed. Most of the opposition against reprocessing of SUDs comes from the original equipment manufacturers (OEMs), whereas the medical community is generally supportive of reprocessing (2). Commentary in the English literature on this subject is relatively sparse. Despite extensive debate in cardiologic publications, there is little pertinent information in interventional journals. Therefore, we are providing our colleagues with insight into the historic and current status of the reprocessing and reuse of SUDs. This commentary is not intended to represent our endorsement or opposition to the practice of reprocessing SUDs.

Comparison of a new recirculation thrombectomy catheter with other devices of the same type: In vitro and in vivo evaluations

Qian Z, Kvamme P, Raghed D, et al. Comparison of a new recirculation thrombectomy catheter with other devices of the same type: in vitro and in vivo evaluations. Invest Radiol 2002;37:503–511. Raionale and Objectives.To compare a new 7 Fr. Helix thrombectomy catheter with Amplatz thrombectomy devices (ATD) with respect to clot fragmentation efficiency, hemolytic potential, and risk for vascular trauma. Materials and Methods.Particle size was evaluated following the maceration of 8-to-10-day-old clots, each weighing 6 ± 0.01 g. The clots were macerated using devices of various sizes, including the 7-Fr. Helix thrombectomy catheter, the 7-Fr. over-the-wire (OTW), 8-Fr. ATD and the 6-Fr. ATD. The number of particles by weight was quantified. The 7-Fr. Helix and the 8-Fr. ATD were tested in the native iliac vein of six dogs without presence of clots. Blood samples were obtained before, during, and at 1, 3, 6, 24, and 48 hours after the procedure, to monitor the hemolytic effects. The treated iliac veins were examined histologically. Results.Most of the clot was fragmented into particles <10 &mgr;m. The mean percentage by weight of the original clot that remained as particles larger than10 &mgr;m was 1.59% in the 7-Fr. Helix group. This was significantly less than 3.10% with the 6-Fr. ATD, 2.57% with 7-Fr. OTW and 2.44% in the 8-Fr. ATD group (<0.01). In vivo results showed a higher plasma free hemoglobin (PFH) level starting 5 minutes after initiating the ATD activation, reaching its peak after completion of the activation, and declining afterward, with return to the baseline at 24 hours. The haptoglobin level tended to decline slightly at 10 minutes, reaching its lowest level at 24 hours, and starting to recover at 48 hours. A similar pattern of PFH and haptoglobin changes was found in both groups. There were no significant differences regarding hemolytic effect of the two tested devices. No significant changes of creatinine were observed for up to 48 hours after procedures. Focal microthrombosis was seen in two sites of two vessels treated with the 7-Fr. Helix and a focal injury of a venous valve was noted in the 8-Fr. ATD group. The media and internal elastic lamina (IEL) were intact in all cases. Conclusion.The newly designed 7-Fr. Helix is more effective in fragmentation in vitro clots than the 6 Fr. ATD, 7-Fr. OTW and the 8-Fr. ATD. The 7-Fr. Helix and the 8-Fr. ATD produced hemolytic effects, but they appeared to be tolerated by the animals. The in vivo results indicated that the 7-Fr. Helix appears to be as safe as the 8-Fr. ATD.

Intimal Dehiscence in the Abdominal Aorta following Balloon Fenestration for Type B Dissection

Purpose: To report a case of intimal dehiscence associated with endovascular intervention in patients with aortic dissection. Case Report: A 65-year-old man presented with a type B dissection extending to the level of the common iliac arteries. Two Talent stent-grafts were placed in the descending thoracic aorta to close the entry point, but 2 lumens remained. Three days later, abdominal pain prompted another imaging session, which demonstrated a large cylindrical filling defect in the abdominal aorta (“tube-in-tube”) assumed to be a partially or completely dehisced intima. Fenestration marginally improved flow to the visceral vessels, and the patient improved clinically. However, 4 days later, recurrent ischemic symptoms prompted surgery; a complete dehiscence of the aortic intima starting at the descending aorta extended to the distal abdominal aorta. The aorta was resected, but the patient died from disseminated intravascular coagulation. Conclusions: Intimal flap dehiscence associated with an endovascular procedure in the management of aortic dissection is an uncommon complication. Early detection and prompt surgical intervention of such a complication could save the patients life. Endovascular procedures are unlikely to resolve the hemodynamic problem caused by a dehisced, distally migrated, collapsed intima.

Animal model of bile duct dilatation created with minimally invasive surgery

RATIONALE AND OBJECTIVES The purpose of the study was to evaluate a method of producing obstruction of the common bile duct and concomitant biliary duct dilatation in an animal model. MATERIALS AND METHODS Laparoscopic placement of a double-balloon occlusion device was used to produce common bile duct obstruction and bile duct dilatation in pigs. RESULTS One week after the procedure, common bile duct obstruction and dilatation of the biliary tree were demonstrated with either percutaneous transhepatic cholangiography or percutaneous cholecystography. CONCLUSION The use of this method is technically feasible and provides a useful subacute and chronic animal model of common bile duct obstruction and dilatation of the biliary tree for percutaneous interventional training and research purposes.

Saphenous Venous Ablation with Hot Contrast in a Canine Model

PurposeTo determine the feasibility, efficacy, and safety of thermal ablation of the saphenous vein with hot contrast medium.MethodsTwelve saphenous veins of 6 dogs were percutaneously ablated with hot contrast medium. In all animals, ablation was performed in the vein of one leg, followed by ablation in the contralateral side 1 month later. An occlusion balloon catheter was placed in the infragenicular segment of the saphenous vein via a jugular access to prevent unwanted thermal effects on the non-target segment of the saphenous vein. After inflation of the balloon, 10 ml of hot contrast medium was injected under fluoroscopic control through a sheath placed in the saphenous vein above the ankle. A second 10 ml injection of hot contrast medium was made after 5 min in each vessel. Venographic follow-up of the ablated veins was performed at 1 month (n = 12) and 2 months (n = 6).ResultsFollow-up venograms showed that all ablated venous segments were occluded at 1 month. In 6 veins which were followed up to 2 months, 4 (66%) remained occluded, 1 (16%) was partially patent, and the remaining vein (16%) was completely patent. In these latter 2 cases, an inadequate amount of hot contrast was delivered to the lumen due to a closed balloon catheter downstream which did not allow contrast to displace blood within the vessel.DiscussionHot contrast medium thermal ablation of the saphenous vein appears feasible, safe, and effective in the canine model, provided an adequate amount of embolization agent is used.