Experimental Assessment of Physician Modified Proximal Scalloped Stent Graft to Extend Proximal Landing Zone in the Aortic Arch.

OBJECTIVE/BACKGROUND: The aim of the study was to assess a model of physician modified scalloped stent graft (PMSG) on currently available thoracic aortic devices to extend the proximal landing zone in either zone 2, 1 or 0 of the aortic arch while preserving flow in the supra-aortic vessels on human cadaveric aorta. METHODS: Fresh human aortas were harvested at autopsy from adult subjects. A proximal scallop was made on the stent grafts based on direct measurements on the aortas to extend the proximal landing zone in zone 0 (n = 5), zone 1 (n = 5), and zone 2 (n = 5). A previously described benchtop closed system pulsatile flow model was used to mimic flow and pressure conditions in the aorta to deploy the stent graft as close to physiological conditions as possible. Deployment accuracy of the scallop opposite the aortic arch branch ostia was assessed by completion angiography and post-procedural analysis of the aortas. RESULTS: Fifteen proximal scalloped stent grafts were deployed in the aortic arch of 15 human cadaveric aortas under fluoroscopy. The expected proximal landing zone was achieved in all cases (zone 2 = 5; zone 1 = 5; zone 0 = 5). Post-procedural angiography and direct visual analysis showed supra-aortic vessel patency and deployment of the scallop opposite the aortic arch branch ostia in all cases. CONCLUSION: PMSG to extend the proximal landing zone in zone 2, 1, or 0 in order to treat urgent diseases of the proximal descending aorta or the inner circumference of the aortic arch by a totally endovascular approach while preserving flow in the supra-aortic trunks is experimentally feasible.

Imaging of postoperative complications following surgery for lung cancer.

The complications following surgery for lung cancer vary depending upon the comorbidities and the type of surgery. Hemorrhage, infections and pulmonary edemas are not specific to the type of resection but frequently occur following pneumonectomies. Morbidity following pneumonectomies is related to the significant changes in the contents of the intrathoracic space. Pulmonary infarction and torsion are emergency situations that develop following lobectomy. CT shows features of localized congestion and stenosis or occlusion of a vein or bronchus. Rapid identification of severe events, in particular by systematic CT is essential for appropriate management of a postoperative or delayed complication of lung cancer surgery.

Normal postoperative appearances of lung cancer.

The major lung resections are the pneumonectomies and lobectomies. The sublobar resections are segmentectomies and wedge resections. These are performed either through open surgery through a thoracotomy or by video-assisted mini-invasive surgery for lobectomies and sublobar resections. Understanding the procedures involved allows the normal postoperative appearances to be interpreted and these normal anatomical changes to be distinguished from potential postoperative complications. Surgery results in a more or less extensive physiological adaptation of the chest cavity depending on the lung volume, which has been resected. This adaptation evolves during the initial months postoperatively. Chest radiography and computed tomography can show narrowing of the intercostal spaces, a rise of the diaphragm and shift of the mediastinum on the side concerned following major resections.

Endovascular management of rupture in acute type B aortic dissections.

OBJECTIVE: Reports of thoracic endovascular aortic repair (TEVAR) for complicated acute type B aortic dissection (ABAD) bring together a large range of clinical presentations. With a 30 day mortality of 50% when managed with open surgery, rupture is the most devastating complication of ABAD. This study investigated the outcome of TEVAR for ABAD complicated by rupture (r-ABAD) to assess the results of this particularly critical subgroup. METHODS: A review of consecutive TEVAR for r-ABAD in two tertiary referral centers was performed using a prospectively maintained database. RESULTS: Between 2000 and 2013, 24 patients (mean age 71 years; 14 males) underwent TEVAR for r-ABAD. Sixteen (67%) were in shock (Systolic blood pressure <80 mmHg) before surgery. Seven patients had coverage of the left subclavian artery, of whom four had partial arch debranching procedures via cervical access concomitant with TEVAR. Median length of aortic coverage was 150 mm, median proximal oversizing was 13.3% (range 6.2-33.3%). Technical success was achieved in 100%. There were four in hospital deaths (16%). Two patients (8%) had paraplegia, but neither stroke nor renal insufficiency requiring dialysis occurred. During a mean follow up of 28 months, there was one aortic dissection related death and eight patients (40% of the surviving patients) required re-intervention. All re-interventions were managed endovascularly. At last follow up CT scan, eight patients (40%) had complete remodeling of the aortic wall. CONCLUSION: With 16% in hospital mortality and 8% early major complications, this study confirms the feasibility of TEVAR for r-ABAD with a lower peri-operative morbidity and mortality rate compared with open surgery. Given the high rate of re-intervention, close follow up is required in surviving patients.

Open surgical secondary procedures after thoracic endovascular aortic repair.

OBJECTIVES: Improved outcomes of thoracic endovascular aortic repair (TEVAR) compared with open repair have changed the therapeutic paradigm of thoracic aortic lesions. As the number of TEVAR survivors has grown, reports of complications have similarly increased. Although secondary endovascular rescue measures are often undertaken, patients with serious complications are often converted, ultimately, to open repair. The aim of this study was to assess causes and midterm results of open surgical secondary procedures after thoracic endovascular aortic repair. METHODS: A total of 236 patients underwent TEVAR. Fourteen of these patients required open repair because of six aortobronchial fistulas, four retrograde type A dissections, two aneurysm enlargement without endoleak, one thoracic stent-graft collapse, and one aortoesophageal fistula. Eight (57.1%) patients underwent surgical repair using cardiopulmonary bypass. Six stent-grafts were totally removed, and eight stent-grafts were left in situ. Four patients underwent supracoronary ascending aorta replacement, and one an extensive replacement of the aortic arch through sternotomy. Three patients had descending aortic replacement through left thoracotomy combined with a total esophagectomy in one case. One patient was treated by ligation of the aortic arch, ascending to supraceliac abdominal aorta bypass and stent-graft explantation. One patient was treated by exclusion bypass of the descending thoracic aorta. Pulmonary resection and large pleural or intercostal muscle flap interposition to wrap the stent-graft left in situ was done in four cases of aortobronchial fistula. RESULTS: All patients survived the surgical procedure. Ten patients (71%) had an uneventful postoperative course. There were two in-hospital deaths (14.3%). Both died from multi-organ failure in the early postoperative course after surgical repair of a stent-graft infection and an aortoesophageal fistula. One patient suffered a definitive paraplegia and a secondary aortoesophageal fistula requiring reoperation for esophageal repair. One patient, treated by pulmonary resection and flap interposition to wrap the stent-graft, underwent stent-graft explantation and in situ descending aortic replacement because of stent-graft reinfection. Actuarial survival was 87.7% after a mean follow-up of 26.3 months (range 9-72 months). CONCLUSIONS: Complications or prevention of complications after TEVAR either due to device failure or adverse events may require conversion to open repair or additional open surgical procedure. Open repair can be performed by a team experienced in management of diseases of the thoracic aorta and a low mortality rate achieved despite the precarious preoperative conditions and complex aortic pathologies of patients.

Endovascular repair of aorto-iliac artery injuries after lumbar-spine surgery.

OBJECTIVE: This study aims to describe the endovascular management of abdominal-aortic- or common-iliac-artery injuries after lumbar-spine surgery. METHODS: Patients treated for abdominal-aortic- or common-iliac-artery injuries after lumbar-spine surgery during a 13-year period were identified from an endovascular database, providing prospective information on techniques and outcome. The corresponding patient records and radiographic reports were analysed retrospectively. RESULTS: Seven patients were treated with acute (n = 3) or subacute (n = 4) injuries of the common iliac artery (n = 6) or abdominal aorta (n = 1) after lumbar-spine surgery. Vascular injuries included arterial lacerations (n = 3), arteriovenous fistulas (n = 2) and pseudo-aneurysms (n = 2). The mean age of the patients was 51.7 years (30-60 years), 71.4% were women. These lesions were repaired by transluminal placement of stent grafts: Passager (n = 3), Viabahn (n = 1), Wallgraft (n = 1), Zénith (n = 1) and Advanta V12 (n = 1). Exclusion of the injury was achieved in all cases. Mortality was nil. There were no procedure-related complications. During a median follow-up of 8.7 years (range 0.3-13 years), all stent grafts remained patent. CONCLUSIONS: Sealing of common iliac artery or abdominal aortic lesions as a complication of lumbar-disc surgery with a stent graft is effective and is suggested as an excellent alternative to open surgery for iatrogenic great-vessel injuries, particularly in critical conditions.

Preoperative assessment of anatomical suitability for thoracic endovascular aortic repair.

Endovascular treatment of descending thoracic aortic pathologies requires a preoperatively determined interventional strategy. Its feasibility depends mainly on anatomic factors: the morphology of the proximal and distal fixation sites, the diameter and disease state of the access vessels. These factors represent important predictors of success and the most important exclusion criteria. Current diagnostic evaluation of aortic aneurysm for endovascular repair relies primarily on CT scan associated with 3D-reconstruction to assess the anatomical suitability for endograft implantation. In patients with an inadequate length of the proximal or distal neck, the left subclavian artery or the coeliac trunk can be overstented to effectively exclude thoracic aortic lesions. Deliberate coverage of aortic side branches should be decided prior to the procedure (guided by a extensive anatomical assessment) or carefully be avoided in order to reduce major morbidity, especially cerebral embolization, spinal cord ischemia and ischemic abdominal complications.

A porcine model of systemic and renal haemodynamic responses to infrarenal aortic cross-clamping.

OBJECTIVES: cross-clamping of the infrarenal aorta is associated with complex haemodynamic disturbances. Several experimental models of aortic cross-clamping (AXC) have been described with heterogeneous results. The main purpose of this study was to establish an animal model in which infrarenal AXC could reproduce similar systemic and renal haemodynamic changes to those observed in humans. METHODS: eleven anaesthetised pigs underwent AXC just below the renal arteries. Renal blood flow was measured using clearance of (131)I hippuran. Systemic and renal parameters were collected at 3 consecutive 30-min periods. RESULTS: AXC did not alter the extraction fraction of (131)I hippuran but was accompanied by significant (13%) decrease in cardiac index (p = 0.005) and a 23% increase in mean arterial pressure (p = 0.005). AXC induced significant 135% increase in renal vascular resistance (p = 0.012) and a 35% decrease in renal blood flow (p = 0.016). This worsened after removal of the aortic clamp, whereas systemic variables returned to baseline levels. CONCLUSIONS: this AXC animal model reproduces the changes observed in humans. It provides a reliable animal model which allows to investigate the underlying mechanisms of renal vasoconstriction and the effect of new drugs.

Surgical exposure of superior sulcus lung tumors with vascular involvement.

Choice of exposure route for surgical excision of superior sulcus lung tumors depends on involvement at the thoracic inlet. From December 1985 to September 1999, we performed surgical treatment of superior sulcus tumors in 42 patients, including 22 with vascular involvement. Various exposure techniques were used, including a novel technique combining transverse supraclavicular cervicotomy and posterolateral thoracotomy in 11 cases, anterior transclavicular cervicothoracotomy in 7 cases, isolated posterolateral thoracotomy in 3 cases, and cervicosternotomy in 1 case. Vascular procedures consisted of subadventitial dissection of the subclavian artery in 5 patients, arterial resection-anastomosis in 7, and prosthetic bypass in 10. Postoperative mortality was 11.9% in the overall series of 42 patients (n = 5) and 9% (n = 2) in the subgroup of patients with vascular involvement. During follow-up, 13 patients died of tumor recurrence and 1 patient died of respiratory insufficiency. Actuarial 5-year survival was 22.7 +/- 17.5% overall and 18 +/- 17.9% in the subgroup of patients with vascular involvement. This study indicates that the combined exposure route with transverse supraclavicular cervicotomy and posterolateral thoracotomy was useful for treatment of superior sulcus lung tumors requiring lobectomy and pneumonectomy.

Management of descending necrotizing mediastinitis: an aggressive treatment for an aggressive disease.

BACKGROUND: Descending necrotizing mediastinitis represent a virulent form of mediastinal infection requiring prompt diagnosis and treatment to reduce the high mortality associated with this disease. Surgical management and a particularly optimal form of mediastinal drainage remain controversial. METHODS: Over a 10-year period, 12 patients were treated at our institution. Surgical treatment consisted of 1 or several cervical drainages, associated with drainage of the mediastinum through a thoracic approach in 11 patients. Thoracic procedures included radical surgical debridement of the mediastinum with complete excision of the tissue necrosis, decortication, and pleural drainage with adequate placement of chest tubes for mediastinopleural irrigation. Transcervical mediastinal drainage was performed in only 1 patient. RESULTS: The outcome was favorable in 10 patients, 9 of whom had mediastinal drainage through thoracotomy. Two patients were initially drained through a minor thoracic approach; the first died of tracheal fistula and the second required new drainage through a thoracotomy. The patient who had transcervical mediastinal drainage without a thoracic approach presented an abscess limited to the anterior and superior mediastinum. In 3 patients, ongoing mediastinal sepsis required a second thoracotomy. CONCLUSION: A stepwise approach with transcervical mediastinal drainage is first justified in patients with very limited disease to the upper mediastinum. However, ongoing mediastinal sepsis requires new drainage, through a major thoracic approach, without delay. Extensive mediastinitis can not be adequately treated without mediastinal drainage including a thoracotomy. This aggressive surgical policy has allowed us to maintain a low mortality rate (16.5%) in a series of 12 patients with this highly lethal disease.

Endovascular management of traumatic infrarenal abdominal aortic dissection.

Dissection is a recognized finding after blunt trauma to the abdominal aorta. Immediate and long-term prognosis is poor without surgical treatment especially since most patients present severe associated injuries. On the basis of encouraging results using endovascular techniques to treat experimental dissection of the descending thoracic aorta, we treated three patients with traumatic infrarenal abdominal aortic dissection by percutaneous stent placement. There were two men 34 and 41 years of age and one 89-year-old woman. In all patients, dissection began in the infrarenal portion of the aorta and extended into the iliac arteries. All patients had multiple associated injuries. The main symptoms were acute abdominal pain (two patients) and ischemia of the lower extremities (two patients). Diagnosis was missed in one patient despite exploratory laparotomy for an associated injury. Two patients were treated in the acute phase by placement of a self-expanding endovascular prosthesis at the aortoiliac level. The third patient was treated in the chronic phase by placement of a balloon-expandable endovascular stent. All procedures were performed uneventfully by femoral route. Success of treatment was confirmed by arteriography and computed tomography (CT) scan demonstrating obliteration of the dissection. Upon late follow-up examination, all patients were in satisfactory condition, with normal Doppler ultrasound findings. These findings confirm experimental studies using endovascular treatment for dissection of the descending thoracic aorta and are promising for future clinical management.

Dissection of the abdominal aorta in blunt trauma: management by percutaneous stent placement.

We implanted stents in three patients who had traumatic abdominal aortic dissections, complicated by right limb ischemia in one case. The circulating false channel extended to the left iliac artery in one case and to both iliac arteries in the last case. Diagnosis and radiological follow-up included ultrasound, computed tomography, and arteriography. Two patients were treated with Wallstents, one with a Palmaz stent. The occlusion of the false channel was obtained in all patients without any significant residual stenosis. No early or late complication was noted in any of the patients. The longest follow-up was 2 years. We conclude that stent placement is an efficient method for the treatment of noniatrogenic inframesenteric aortic dissections.

Cervical-to-petrous internal carotid artery saphenous vein in situ bypass for the treatment of a high cervical dissecting aneurysm: technical case report.

OBJECTIVE AND IMPORTANCE: We describe a novel cervical-to-petrous internal carotid artery (ICA) saphenous vein in situ bypass for the treatment of a high cervical dissecting aneurysm. The cervical ICA has no major collateral branches and can be used as a tunnel for the vein graft. CLINICAL PRESENTATIONS: A 25-year-old man was involved in a car accident. A cerebral angiogram revealed a right ICA dissection with aneurysm formation at the C1-C2 level. The patient recovered fully and was anticoagulated. Six months after the initial angiogram, a second angiogram disclosed ICA stenosis (80%) and persistence of the traumatic dissecting aneurysm. Definitive surgical bypass was considered the most appropriate course of action. TECHNIQUE: The horizontal portion of the petrous ICA was exposed by an extradural subtemporal approach. The cervical arteries were exposed by a separate surgical incision. After dividing the petrous ICA and the cervical ICA, the cervical ICA was dilated using a Fogarty balloon embolectomy catheter. A saphenous vein graft was inserted inside the lumen of the cervical ICA and was anastomosed to the ICA end-to-end both proximally and distally (cervical-to-petrous ICA in situ bypass). The graft was patent on the follow-up angiogram. CONCLUSION: We describe a new technique that could be considered an alternative to the classical extra-anatomic cervical-to-petrous ICA bypass procedures.

Hypodiploidy, Ki-67 growth fraction and prognosis of surgically resected lung cancers.

One hundred and thirty-seven lung cancer patients (123 non-small-cell lung cancers (NSCLC), 10 small-cell lung cancers (SCLC) and four carcinoid tumours) who underwent surgery in an attempt at complete resection were prospectively entered in a study whose aim was to determine the prognostic significance of a hypodiploidy or a multiploidy pattern of tumour cell DNA content and a high immunohistochemical reactivity of Ki-67, a nuclear antigen related to the cell cycle. Indirect immunoperoxidase reactivity of Ki-67 on frozen tumour tissue sections was evaluated both visually, using a classical semiquantitative scale, and by means of a computer-assisted image processor. Cell DNA content analysis was done using static computer-assisted cytometry on tumour cytological prints stained by the pararosaline Feulgen-Schiff technique. The ploidy was characterised for each tumour by DNA index (DI), percentage of hypodiploid cells and type of DNA content histogram (near diploid, hyperdiploid, hypodiploid and multiploid). Ki-67 immunostaining was negative in 64 tumours (48%) and positive in 69 (52%). DNA histogram classification disclosed 57 (42%) near diploid tumours. Among the 80 (58%) aneuploid tumours, 16 were hypodiploid, 44 hyperdiploid and 20 multiploid. The prevalence of both a positive Ki-67 immunostaining and an aneuploid DNA histogram differed according to histology as SCLC demonstrated a higher frequency of both features when compared with NSCLC and carcinoid tumours. On the other hand, Ki-67 immunostaining and ploidy did not significantly differ according to degree of differentiation, nodal status and Mountain's stage grouping. The percentage of cells in the hypodiploid modal DNA was significantly higher for tumours which demonstrated a high Ki-67 immunostaining, suggesting a link between growth fraction and DNA content abnormalities. In univariate analysis, survival did not differ significantly according to either the Ki-67 immunohistochemical reactivity or the DNA index. Patients with a hypodiploid tumour had a shorter survival than patients with other DNA histogram patterns but, owing to the low frequency of hypodiploidy, this difference did not reach statistical significance. In Cox's proportional hazard model, an SCLC histology, an advanced tumour status, a positive nodal status and a hypodiploid tumour (hazard ratio: 2.070; 95% confidence interval 1.041-4.116) were significant determinants of survival. We conclude that hypodiploidy in lung cancer is a distinct DNA content abnormality as it contributes significantly to prognosis. Neither visually assessed nor computer-generated Ki-67 immunostaining measurements significantly determine prognosis.

Bilateral splenorenal bypass and axillofemoral graft for management of juxtarenal mycotic aneurysm.

The principles of treatment of mycotic aortic aneurysms are not well established and the optimal method of revascularization--extra-anatomic bypass or in situ grafting--is still debated. Infection of the juxtarenal or suprarenal aorta poses an additional challenge in management because of the requirement for visceral revascularization. The case of a 73-year-old man is reported who developed several mycotic aneurysms of the juxtarenal, infrarenal aorta and right main iliac artery following a Candida infection. He was successfully treated with suprarenal aortic ligation, aneurysmal excision, splenorenal bilateral bypass and systemic antifungal therapy. The patient subsequently underwent extra-anatomic revascularization of the lower extremities with a left axillobifermoral bypass involving a polytetrafluoroethylene graft.

Intravascular stenting of traumatic abdominal aortic dissection.

PURPOSE: We describe the case of a 34-year-old man with blunt abdominal trauma. Initial abdominal computed tomography scan showed retroperitoneal hematoma, pancreatic contusion, multiple fractures of the transverse process in the thoraco-lumbar spine, and infrarenal aortic dissection. METHOD: Angiography revealed that the aortic dissection originated proximal to the inferior mesenteric artery and extended down to the left common iliac artery without vascular obliteration. The pancreatic trauma was managed without operation, and the dissection was treated with aortic and left iliac endovascular self-expanding Schneider Wall Stents. RESULT: Immediate angiographic and computed tomography scan examination showed the obliteration of the greater part of the dissection with persistence of a short dissected segment at the level of the aortic bifurcation. Examination a week later showed thrombosis of this false lumen and complete obliteration of the dissection. CONCLUSION: Intravascular stenting allowed treatment of the dissection without open surgical procedures requiring laparotomy and aortic operation.

Ruptured abdominal aortic aneurysm: influence of intraoperative management on surgical outcome.

PURPOSE: This study was designed to determine the influence of changes in intraoperative management on the outcome of ruptured abdominal aortic aneurysm (RAAA). METHODS: Retrospective review of our surgical experience of RAAA identified 61 patients and was separated into two periods: 1986 to 1988 (group 1 [n = 21 patients]) and 1989 to 1994 (group 2 [n = 40 patients]). Since 1989 operations have been conducted by two vascular surgeons without systemic administration of heparin and with control of suprarenal aorta if extensive hematoma is present, use of collagen-impregnated grafts, preferential repair with aortoaortic grafting, and routine use of intraoperative autotransfusion. RESULTS: Factors differing between the groups were use of intraoperative autotransfusion (4.76% in group 1 vs 80% in group 2, p < 0.00001), repair with tube grafting (42.8% in group 1 vs 80% in group 2, p = 0.003), number of packed homologous red blood cells (7.5 +/- 5.2 units in group 1 vs 3.1 +/- 3.6 units in group 2, p = 0.008), postoperative blood loss (365 +/- 705 ml in group 1 vs 133 +/- 351 ml in group 2, p = 0.01). The intraoperative mortality rate was significantly lower in group 2 (5% vs 28.6%, p = 0.016). The only predictive factor was the use of intraoperative autotransfusion with a lower mortality rate in patients undergoing autotransfusion (p = 0.029). The postoperative mortality rate was significantly lower in group 2 (20% vs 52.4%, p = 0.009). Predictive factors were use of intraoperative autotransfusion (p = 0.0009), age of the patients (p = 0.0039), and repair with tube graft (p = 0.039). The odds ratio of postoperative death was 25 times higher without intraoperative autotransfusion and seven times lower when a tube graft was used. CONCLUSION: Continuing efforts to achieve improvement in surgical technique and use of intraoperative autotransfusion were important determinants in lowering the postoperative mortality rate of RAAA to 20%.

Membranous tracheal rupture after endotracheal intubation.

BACKGROUND: Tracheobronchial rupture after tracheal intubation has been infrequently reported. We report 6 cases of membranous tracheal rupture after endotracheal intubation treated at our institution over 7 years. METHODS: Overinflation of the tracheal cuff was speculated to be a frequent cause of the tracheal damage because the lesion was always a linear laceration of the posterior membranous wall. The diagnosis was suspected on the basis of common signs such as subcutaneous emphysema, respiratory distress, pneumomediastinum, and pneumothorax. Fiberoptic bronchoscopy was the best means of confirming the diagnosis and determining the location and extent of the lesion. In 5 patients, extensive laceration with severe respiratory disorders required emergent repair through a right posterolateral thoracotomy. RESULTS: There were two postoperative deaths unrelated to the tracheal lesion. A patient with a small tracheal defect and favorable clinical presentation showed a rapid positive outcome after conservative treatment. CONCLUSIONS: Tracheal intubation-related airway ruptures are rare but probably underestimated. Early recognition and emergent repair are essential, because failure to do so could result in potentially lethal events.

Tracheoesophagogastric anastomosis fistula: a rare complication of esophagectomy.

Fistulas between trachea and esophagogastric anastomosis after esophagectomy are uncommon. We describe 2 patients with such a lesion successfully managed with single-stage repair. The fistula was divided, the tracheal defect was closed directly or with a free pericardial graft, and the esophagogastric anastomosis was redone. A muscle or pleural flap was used to separate the tracheal and digestive suture lines. This treatment of a potentially life-threatening condition yielded excellent results without postoperative complications.

Typical and atypical bronchopulmonary carcinoid tumors: a clinicopathologic and KI-67-labeling study.

Expression of a proliferating antigen by KI-67 immunohistochemistry was analyzed with a SAMBA 2005 computer-assisted image processor (Traitement de l'Information for des Techniques Nouvelles, Grenoble, France) in 47 surgically resected bronchopulmonary carcinoids embedded in paraffin. The clinicopathologic characteristics and KI-67 labeling, expressed in percentage of stained nuclear surface relative to the total nuclear surface, of 31 typical carcinoids and 16 atypical carcinoids were compared and assessed with respect to patient survival. The proliferation status was significantly higher in histologically atypical than in typical carcinoids. Moreover, using a 4% cutoff, we observed a significant difference for the 4-year overall survival rate. Semiquantitative analysis of the proliferation index by KI-67 immunostaining seemed to be an effective means of identifying high risk subsets among patients with histologically atypical carcinoids and for whom adjuvant chemotherapy could be proposed.