Pulmonary arteriovenous malformation: a rare, treatable cause of stroke in young adults

Pulmonary arteriovenous malformation (PAVM) predisposes affected patients to a significantly increased risk of stroke. Most commonly, PAVM is seen in patients with hereditary haemorrhagic telangiectasia (HHT), an inherited disorder that can be difficult to diagnose in young people because of variable age-related penetrance. As such, stroke in the young adult may be the presenting feature of underlying PAVM in a previously undiagnosed patient. The importance of considering this diagnosis in the evaluation of young adults with cryptogenic stroke is underscored by the availability of both sensitive screening and effective treatment for PAVM, from which this at-risk population can greatly benefit.

Pulmonary arteriovenous malformations: overview and transcatheter embolotherapy

Pulmonary AVMs are most commonly seen in patients with HHT, a fascinating multi-system disorder that is all too often underdiagnosed and undertreated. Not only a medical curiosity, HHT is a serious condition that causes substantial morbidity and mortality. Pulmonary AVMs are effectively and safely treated by transcatheter embolotherapy.

Contrast echocardiography for detection of pulmonary arteriovenous malformations

BACKGROUND

Pulmonary arteriovenous malformations (PAVMs) lead to stroke, brain abscess, and hemorrhage in hereditary hemorrhagic telangiectasia (HHT). The current screening approach for PAVMs in HHT patients with chest radiograph (CXR) and oxygen shunt study has not been validated and is thought to be insensitive. We hypothesized that agitated saline contrast echocardiography (ECHO) would be a useful screening test for PAVMs.

METHODS AND RESULTS

A total of 106 sequential HHT patients underwent screening for PAVMs with ECHO in a prospective study. If the test was positive, or if the CXR or shunt study suggested PAVMs, pulmonary angiography was performed. A positive ECHO was defined as appearance of bubbles in the left atrium after injection of agitated saline solution. A positive shunt study was defined as a partial pressure of oxygen in arterial blood <500 mm Hg while breathing 100% oxygen. The mean age was 41 years (range 15-80 years); 66% were female. Forty-four patients had positive ECHO. Forty-one of the 44 patients underwent angiography. Three patients declined further testing. Thirty-three of the 41 patients who underwent angiography were diagnosed with PAVMs. Of the 62 patients with a negative ECHO, 18 underwent angiography because of either a shunt study or CXR that was suggestive of PAVMs. Of these 18 patients, 2 had PAVMs. In the total population of 106 patients, 35 (33%) had PAVMs. ECHO was the only positive screening test in 11 of 35 (31%) patients. The diagnosis of PAVMs in these 11 patients would have otherwise been missed.

CONCLUSIONS

ECHO is a useful screening tool for PAVMs in HHT.

Transcatheter embolotherapy of maternal pulmonary arteriovenous malformations during pregnancy

STUDY OBJECTIVES

To determine if transcatheter embolotherapy is safe and effective for the treatment of pulmonary arteriovenous malformations during pregnancy.

DESIGN

Prospective study.

SETTING

Specialized hereditary hemorrhagic telangiectasia centers at Yale University School of Medicine and St. Michael's Hospital, University of Toronto.

PATIENTS

Seven pregnant women (age range, 24 to 34 years; gestational age range, 16 to 36 weeks) undergoing transcatheter embolotherapy.

INTERVENTIONS

Transcatheter embolotherapy in all patients.

MEASUREMENTS AND RESULTS

Thirteen pulmonary arteriovenous malformations in seven patients were embolized with detachable silicone balloons and/or stainless steel coils without incident. The estimated fetal radiation dose ranged from < 50 to 220 mrad. No complications of pulmonary arteriovenous malformations occurred in any of the patients after transcatheter embolotherapy. The mothers went on to deliver healthy babies in all cases.

CONCLUSIONS

Transcatheter embolotherapy of maternal pulmonary arteriovenous malformations performed by an experienced radiologist appears to be safe and effective after 16 weeks of gestational age.

Diffuse pulmonary arteriovenous malformations: characteristics and prognosis

OBJECTIVE

To study the clinical characteristics and prognosis of patients with diffuse pulmonary arteriovenous malformations (AVMs).

DESIGN

Retrospective chart review of all patients (n = 16) with diffuse pulmonary AVMs seen at Yale New Haven Hospital, Johns Hopkins Hospital, and St. Michael's Hospital. Up-to-date follow-up information was obtained in all living patients.

RESULTS

All patients were severely hypoxic. Neurologic complications (stroke or brain abscess) had occurred in 70% of patients by the time of diagnosis. During the follow-up period (mean, 6 years), three patients died and two others developed new neurologic complications. One of the deaths occurred perioperatively during lung transplantation. All patients underwent transcatheter embolotherapy of any large pulmonary AVMs. A selected group underwent pulmonary flow redistribution, a novel technique. Oxygenation did not improve significantly with embolotherapy of the larger AVMs, but there was a small significant improvement in those patients who underwent pulmonary flow redistribution. The majority (85%) of the living patients are currently working or studying full-time.

CONCLUSIONS

Patients with diffuse pulmonary AVMs are at increased risk of neurologic complications. Transcatheter embolotherapy does not significantly improve the profound hypoxia, but it may reduce the risk of neurologic complications. Antibiotic prophylaxis is recommended for bacteremic procedures to prevent brain abscess. These patients can live for many years and lead productive lives. We do not recommend lung transplantation because survival with disease is difficult to predict and we have observed a perioperative transplant death.

Radiologic peroral gastrostomy

PURPOSE

To develop an improved percutaneous technique for the insertion of large-bore gastrostomy tubes.

MATERIALS AND METHODS

With use of fluoroscopic guidance, the stomach is punctured and the esophagus is catheterized in a retrograde fashion. A guide wire is passed from the gastrostomy site, up the esophagus, and out of the patient's mouth. A large-bore (20-24 F) endoscopic push-type gastrostomy tube is advanced over the wire, through the mouth, down the esophagus, and out of the gastrostomy site.

RESULTS

Thirty-one successful tube placements were performed in 32 attempts (97% success rate). There were no major procedural or postprocedure complications. Minor complications included one lip laceration (one of 31 = 3%), one minor exit site infection (one of 31 = 3%), and two inadvertent tube dislodgements (two of 31 = 6%).

CONCLUSIONS

Radiologic placement of large-bore endoscopic gastrostomy tubes is possible without endoscopy. The procedure is rapid, easy to perform, and safe.

Predicting infection in localized intraabdominal fluid collections: value of pH and pO2 measurements

PURPOSE

To evaluate the use of pH, pO2, and the subjective opinion of the radiologist compared with bacterial culture in accurate diagnoses of bacterial infection in intraabdominal fluid collections.

MATERIALS AND METHODS

Prospectively, 79 patients who were suspected of having an intraabdominal fluid collection underwent diagnostic fluid aspiration. The aspirate was cultured and measured for pH and pO2. A pH < or = 7.1 and a PO2 < or = 49 mm Hg were threshold values used to separate infected from sterile fluid collections.

RESULTS

pH alone had a 92% sensitivity and 79% specificity, whereas PO2 alone had a 51% sensitivity and 79% specificity. pH or pO2 combined yielded a 92% sensitivity and 60% specificity. The radiologist's opinion produced a 83% sensitivity and 92% specificity. pH and the radiologist's opinion combined produced a 78% sensitivity and 96% specificity. pH or the radiologist's opinion combined had a 95% sensitivity and a 63% specificity.

CONCLUSION

pH is the most sensitive indicator of infection and the radiologist's opinion is the most specific. We recommend proceeding to drainage if the radiologist believes the collection to be infected and performing pH analysis if not. If the pH < or = 7.04, proceed to drainage. If neither of the above criteria are met, drainage could be delayed, pending the results of culture.

Outpatient percutaneous nephrostomy

PURPOSE

To assess the feasibility of performing percutaneous nephrostomy (PCN) on an outpatient basis in a select group of patients.

MATERIALS AND METHODS

In 6 years, 60 PCN procedures were performed in a subgroup of 48 patients (22 men, 26 women) carefully selected from a larger group of 881 nephrostomy procedures in 589 patients. Exclusion criteria included hypertension; untreated urinary tract infection, coagulopathy, and staghorn calculi. Indications were calculus (n = 17), benign stricture (n = 10), and malignant ureteric obstruction (n = 21).

RESULTS

There was 100% technical success. Six of 48 patients (12%) were admitted within a week of PCN; there were no cost savings in these patients. Three of these patients (6%) were admitted as a direct consequence of PCN; one had sepsis, one had bleeding, and one was unable to manage the PCN tube. Outpatient treatment saved the cost of hospitalization in 42 patients (88%).

CONCLUSION

Outpatient PCN is feasible and safe in carefully selected patients and yields major cost savings because it precludes hospital admission.

Pulmonary complications in inhalation injuries with associated cutaneous burn

This retrospective study of 100 consecutive patients with inhalation injury documents that adult respiratory distress syndrome (ARDS) and pneumonia are common complications. Pulmonary complications cause or directly contribute to death in 77% of patients with combined inhalation and cutaneous burn injury. Additionally, the high fluid requirements of these patients worsens their pulmonary injury and is associated with adverse outcome. Independent factors predictive of death include ARDS and expected fluid requirements as well as age and percentage of total body surface area burned. An abnormal chest roentgenogram in the first 48 hours after injury is also associated with death. The development of ARDS is predicted by the actual volume of fluid resuscitation, despite normal pulmonary wedge pressure or normal central venous pressure reflecting increased microvascular permeability. These findings indicate a need for reevaluation of fluid resuscitation of patients with inhalation injury.

Ultrasound guidance in percutaneous gastrostomy and gastrojejunostomy

OBJECTIVE

To evaluate the utility of ultrasound (US) guidance in the percutaneous placement of gastric feeding tubes in patients in whom placement of a nasogastric tube is not possible.

PATIENTS AND METHODS

Records from feeding tube placements performed between January 1991 and August 1994 were reviewed. Of the 238 procedures performed, 27 cases (11%) involved initial US guidance, rather than nasogastric tube assistance, because of upper gastrointestinal obstruction.

RESULTS

US allowed rapid puncture and subsequent insufflation of the stomach in 26 of the 27 patients, and there were no complications related to its use. In the other patient the position of the transverse colon prevented suitable visualization for puncture, and surgical placement of the feeding tube was necessary.

CONCLUSION

US guidance is a safe and effective means by which the stomach can be punctured and distended before placement of a percutaneous feeding tube for patients in whom nasogastric intubation is not possible.

Manipulation by catheter of unopened LGM filter

The use of the transfemoral and transjugular venous routes for placement of inferior vena cava filters is accepted practice. However, the transjugular route is associated with substantially higher rates of incomplete filter opening for the LGM Vena Tech filter (Vena Tech, Evanston, Ill.). The appropriate course of action when a filter fails to open is unclear from the literature. Current recommendations include close observation or placement of a second filter above the unopened device. The authors report a case in which an incompletely opened filter delivered through the transjugular route was directly manipulated with a multipurpose catheter. The filter opened sufficiently to provide stability and obviate the need for a second filter. The authors recommend that manipulation by catheter be considered as the first option at the time of placement should an LGM filter fail to open completely.

Perforating duodenal diverticulitis

Two cases of perforating duodenal diverticulitis are reported, one with enterolith formation, and the other with sonographic evidence of retroperitoneal emphysema. The possible complications of duodenal diverticula, as well as the difficulties encountered in preoperative diagnosis, are discussed.