Endoscopic procedures for resection of arteriovenous malformations

BACKGROUND

Resection of arteriovenous malformations (AVMs), particularly those located in functional areas, requires precision. To enhance that precision, endoscope-assisted microsurgery has been employed at Loma Linda University.

METHODS

Twenty-five consecutive cases of AVM were treated microsurgically with endoscopic assistance. Patients were divided into two groups: (1) those having AVMs in functional areas, and (2) those whose AVMs extended into the ventricle, either in the trigonal area or the capsulocaudatothalamic area. The endoscope was inserted into the subarachnoid space to interrupt communicating venules around the major draining vein and into the cleavage developed between the AVM venous loops and surrounding brain tissue as shunting arterioles and communicating venules were interrupted. For surgery of intraventricular AVMs, the curved endoscope was inserted into the ventricle, providing visualization of the AVM core, which was dissected from the ventricular side.

RESULTS

AVMs were totally resected in all cases except for two patients with capsulocaudatothalamic AVMs, which were decreased in size sufficiently to receive radiosurgery.

CONCLUSION

Endoscope-assisted microsurgery enhances magnification, illumination, and technical precision while the surgeon is dissecting the AVM core vessels and while operating on AVMs extending into the ventricle.     

Hemoptysis from an unusual pulmonary arteriovenous malformation

We report the case of a 64-year-old woman who presented with massive hemoptysis. She was found to be bleeding from a pulmonary arteriovenous malformation in the right middle lobe, which had a peculiar blood supply from the right internal mammary artery. Video-assisted thoracic surgery lobectomy was successfully performed for this condition. Limitations of embolization as a treatment modality for this condition are discussed.     

Brain abscesses associated with pulmonary arteriovenous malformations

We present three patients with brain abscesses who also had pulmonary arteriovenous malformations (AVMs). All patients had hereditary haemorrhagic telangiectasia (Osler's Disease). It is probable that the lung AVMs contributed to the development of the brain abscesses by allowing bacteria easier access to the systemic circulation through a right to left pulmonary vascular shunt, bypassing the filtering action of the pulmonary capillaries. In addition, one patient required a period of postoperative ventilation using PEEP, which may have exacerbated the shunt through the lung AVM and led to difficulty in weaning her from the ventilator.     

VATS anatomic pulmonary resection in octogenarians

Although modern techniques in anesthesia and surgery have reduced morbidity and mortality for pulmonary resection, some physicians still consider advanced age a contraindication to resection of lung cancer. We examined our experience with VATS lobectomy in octogenarians at Cedars-Sinai Medical Center over 12 years (1992-2004). There were 159 patients. Mean age was 83 years (range, 80-94 years) consisting of 61 males (38%) and 96 females (62%). Operations included 153 lobectomies (96%), 3 bilobectomies (2%), and 3 pneumonectomies (2%). Two operations were converted to thoracotomy (1%), one due to bleeding, and one due to poor visualization. Median hospital stay was 4.00 +/- 6.39 days. One hundred thirty-one patients (82%) had no complications. The most common complication was arrhythmias occurring in 8/159 (5%) patients. There were three perioperative deaths (1.8%). Pathology revealed 104 adenocarcinomas (65%), 25 squamous cell carcinomas (16%), 5 adeno-squamous carcinomas (3%), 7 bronchoalveolar carcinomas (4%), 7 large cell carcinomas (4%), 4 carcinoid tumors (3%), 4 non-small cell lung cancer (NSCLC) (3%), 1 mucoepidermoid carcinoma (< 1%), 1 lymphoma (< 1%), and 1 pulmonary metastasis (< 1%). Median follow-up was 29 months. The results of this series show that age alone is not a contraindication to the surgical treatment of lung cancer.     

Stereotactic craniotomy in the resection of small arteriovenous malformations

Surgical resection of 10 obscure arteriovenous malformations (AVM's) was accomplished with craniotomy guided by computerized tomography (CT) or angiography and the use of the Brown-Roberts-Wells stereotactic frame. Stereotactic craniotomy was invaluable for resection of the following types of AVM's: 1) AVM's with a nidus less than 2 cm in diameter, 2) AVM's located in an eloquent area of the brain, and 3) AVM's located deep in the brain. Stereotactic localization of these AVM's on preoperative radiological studies provides a precise route to the nidus, often avoiding important areas of the brain. This series included six male and four female patients with a mean age of 32 years. All patients presented with an intracerebral hemorrhage, from which eight made a complete neurological recovery prior to surgery. Two AVM's were located on the cortex, three were found subcortically, and five were situated near the ventricles or in the deep white matter. As a guide, angiography was used in six cases and CT in four cases. In each instance, the study providing the best image of the AVM nidus was employed. Postoperatively, no neurological deficits were found in eight patients and, in the two patients with preoperative deficits, neurological improvement was observed after recovery from surgery. Postoperative studies revealed complete removal of the AVM in all patients, and all lesions were confirmed histologically. The authors conclude that stereotactic craniotomy provides the optimum operative approach for the localization and microsurgical resection of AVM's that are either obscure or located deep in the brain.     

Embolization using hydrogel-coated coils for pulmonary arteriovenous malformations

PurposeTo prospectively evaluate the efficacy and safety of embolization using hydrogel-coated coils for the treatment of pulmonary arteriovenous malformations (PAVMs).Materials and methodsThe outcomes of 21 PAVMs in 19 patients (3 men and 16 women; mean age, 58.8 ± 15.2 [SD] years; age range 14–78 years) treated by venous sac embolization (VSE) with additional feeding artery embolization were prospectively evaluated. For VSE, using one or more 0.018-inch hydrogel-coated coils was mandatory. Recanalization and/or reperfusion were evaluated by pulmonary arteriography 1 year after embolization.ResultsThe mean feeding artery and venous sac sizes were 4.0 mm and 8.5 mm, respectively. Embolization was successfully completed in 20/21 PAVMs, yielding a technical success rate of 95%. The feeding artery was also embolized in 17/20 successful PAVMs (85%). A technical failure occurred in one PAVM, where embolization was abandoned because of migration of one bare coil to the left ventricle. The mean numbers of hydrogel-coated coils and bare platinum detachable coils used for VSE were 3.3 ± 2.1 (SD) (range, 1–8) and 4.4 ± 3.9 (SD) (range, 1–17), respectively. The mean percentages of hydrogel-coated coils in number, length, and estimated volume were 42.9%, 33.3%, and 72.7% respectively. One patient with one PAVM was lost to follow-up after 3 months. Neither recanalization nor reperfusion was noted in the remaining 19 PAVMs (success rate, 19/19 [100%]). One grade 4 (coil migration) adverse event occurred, and it was treated without any sequelae.ConclusionVSE using hydrogel-coated coils with additional feeding artery embolization is a safe and effective treatment for PAVM.     

Video-assisted thoracoscopic wedge resection for pulmonary sequestration

A 60-year-old woman underwent a video-assisted thoracoscopic wedge resection of intralobar pulmonary sequestration instead of a lobotomy because the lesion was localized in the right basal segment. Preoperative 3-dimensional computed tomography was useful for identifying an aberrant artery arising from the thoracic aorta and distributing to the lesion. A successful outcome more than 4 years after the surgery indicates that a wedge resection under video-assisted thoracoscopy may prove to be a therapeutic option for localized pulmonary sequestration.     

Pulmonary resection for Mycobacterium xenopi pulmonary infection.

Background. Results of medical therapy for Mycobacterium xenopi pulmonary infection remain unreliable. Pulmonary resection may be beneficial to patients whose disease is localized and who can tolerate a resectional operation.

Methods. Eighteen patients underwent pulmonary resection between 1991 and 2000: 14 men and 4 women, with a mean age of 50 ± 12 years (range 27 to 68 years). Indications for operation were either therapeutic (n = 9) or diagnostic (n = 9). Four patients received antimycobacterial chemotherapy before their operation and 2 patients were HIV positive.

Results. Therapeutic procedures included completion pneumonectomy (n = 1), lobectomy (n = 6), segmentectomy (n = 1), and bilateral wedge resection (n = 1). Diagnostic procedures included lobectomy (n = 1) and wedge resection (n = 8). Complete resection could be achieved in 15 patients (83%). There was no in-hospital mortality. Postoperative complications included prolonged air leak (5 of 18 patients, 27.7%) and pleural effusion requiring insertion of a new chest tube (3 of 18 patients, 16.6%). Mean hospital stay was 14 ± 8 days. Follow-up was 100% complete. Eleven patients received antimycobacterial chemotherapy for 4 to 24 months, postoperatively. Late mortality was 11% and was unrelated to progression of mycobacterial disease. After the operation, the sputum remained positive in only 2 patients (11%) with incomplete resections. Fourteen patients were asymptomatic with no relapse at a mean follow-up of 38 ± 22 months (range 85 to 13 months).

Conclusions. Resection represents an important adjunct to chemotherapy for the treatment of M xenopi pulmonary disease. In the setting of localized nodular or cavitary disease, failure to respond to medical therapy, relapse after treatment discontinuation, coexistent aspergilloma or polymicrobial contamination, or patient intolerance of medical therapy, pulmonary resection can be undertaken with acceptable morbidity and mortality.     

Acute exacerbation of interstitial fibrosis after pulmonary resection

Idiopathic pulmonary fibrosis is a chronic diffuse lung disease of unknown cause, and a risk factor for increasing morbidity and mortality after lung resection. Acute exacerbation of idiopathic pulmonary fibrosis after lung surgery for lung cancer is rare. The outcome is unsatisfactory despite therapy. We report two cases of acute exacerbation of idiopathic pulmonary fibrosis after resection for lung cancer.     

The case against staged operative resection of cerebral arteriovenous malformations

Three cases of large cerebral arteriovenous fistulae are presented in which surgical ablation was complicated by brain swelling from hyperperfusion breakthrough believed to be caused by acute intraoperative hypoperfusion superimposed on chronic preoperative hypoperfusion. On the basis of these cases, experimental data, and theoretical considerations, we seriously question the wisdom of using staged surgical resection of cerebral arteriovenous malformation to prevent complications related to alterations in cerebral hemodynamics. The reasons for this concern are: the repeated occurrence of acute-on-chronic hypoperfusion during staged resection; a lack of understanding of the time course for the correction of a disordered autoregulation; risk of hemorrhage between the initial and final resection; difficulty in assessing and substantiating flow reduction after subtotal resection; the rapidity of collateralization; the divergence of flow from large, readily accessible feeding arteries to deep penetrating vessels; and attenuation of the wall thickness in collateral vessels as a consequence of increased flow.     

Development of pulmonary arteriovenous malformations after modified Fontan operations

Two patients with complex cyanotic congenital heart disease and without previous Glenn anastomosis underwent modified Fontan operations. Postoperatively, pulmonary arteriovenous malformations developed that resulted in cyanosis from significant intrapulmonary right-to-left shunting. These malformations were detected by pulmonary angiograms and contrast echocardiograms. Pulmonary arteriovenous malformations may be a major cause of late clinical deterioration in patients treated with modified Fontan operations.     

Nitric oxide in pulmonary arteriovenous malformations and Fontan procedure

Pulmonary arteriovenous malformations are a well documented complication of superior cavopulmonary (Glenn) connections. We report the successful management of a case of severe hypoxemia in the early postoperative period of a patient who underwent the Fontan operation. The patient had previously been diagnosed with pulmonary arteriovenous malformations; the use of inhaled nitric oxide was followed up with reversal of life-threatening hypoxemia. At 6-month postoperative follow-up, the patient was asymptomatic with near normal aortic saturation.     

Pulmonary resection for Mycobacterium xenopi pulmonary infection

Background. Results of medical therapy for Mycobacterium xenopi pulmonary infection remain unreliable. Pulmonary resection may be beneficial to patients whose disease is localized and who can tolerate a resectional operation.Methods. Eighteen patients underwent pulmonary resection between 1991 and 2000: 14 men and 4 women, with a mean age of 50 ± 12 years (range 27 to 68 years). Indications for operation were either therapeutic (n = 9) or diagnostic (n = 9). Four patients received antimycobacterial chemotherapy before their operation and 2 patients were HIV positive.Results. Therapeutic procedures included completion pneumonectomy (n = 1), lobectomy (n = 6), segmentectomy (n = 1), and bilateral wedge resection (n = 1). Diagnostic procedures included lobectomy (n = 1) and wedge resection (n = 8). Complete resection could be achieved in 15 patients (83%). There was no in-hospital mortality. Postoperative complications included prolonged air leak (5 of 18 patients, 27.7%) and pleural effusion requiring insertion of a new chest tube (3 of 18 patients, 16.6%). Mean hospital stay was 14 ± 8 days. Follow-up was 100% complete. Eleven patients received antimycobacterial chemotherapy for 4 to 24 months, postoperatively. Late mortality was 11% and was unrelated to progression of mycobacterial disease. After the operation, the sputum remained positive in only 2 patients (11%) with incomplete resections. Fourteen patients were asymptomatic with no relapse at a mean follow-up of 38 ± 22 months (range 85 to 13 months).Conclusions. Resection represents an important adjunct to chemotherapy for the treatment of M xenopi pulmonary disease. In the setting of localized nodular or cavitary disease, failure to respond to medical therapy, relapse after treatment discontinuation, coexistent aspergilloma or polymicrobial contamination, or patient intolerance of medical therapy, pulmonary resection can be undertaken with acceptable morbidity and mortality.