What technical barriers exist for real-time fluoroscopic and video image overlay in robotic surgery?

BACKGROUND: A hypothetical advantage of the da Vinci console is its ability to integrate multiple visual data sources. Current platforms for augmented reality surgery fuse pre-operative radiographic studies but are limited with their ability to update with intra-operative imaging. The aim of our study was to evaluate the feasibility of real-time radiographic image overlay with current technology. METHODS: S-video composite output from a fluoroscopic C-arm was superimposed onto the video output of the da Vinci device. Image superimposition disparity measurements were evaluated in a bench model. The feasibility of robotic dissection assisted by real-time cholangiogram and intravenous pyelogram was evaluated. RESULTS: Image alignment resulted in a radiographic blind spot and image disparity with severely limited application in an in vivo model. CONCLUSIONS: External collisions of the robotic device and visual disparity in multiple planes negate the current implementation of fluoroscopic overlay and will require more elegant methods of computer-assisted registration.

Robotic intercostal nerve graft for reversal of thoracic sympathectomy: a large animal feasibility model.

BACKGROUND: A subset of patients who undergo video-assisted thoracoscopic sympathectomy for hyperhydrosis develop post-procedure compensatory sweating that is perceived as more debilitating than their initial complaints. We propose a novel treatment to reverse sympathectomy by implantation of an intercostal nerve graft using the da Vinci robot. METHODS: A robotic swine model was established using single-lung ventilation and four ports. The pleura was incised and a representative segment of sympathetic chain was transected. A nearby intercostal nerve was harvested and sutured to the sympathetic chain using four interrupted 10-0 nylon sutures on the epineurium. RESULTS: The intercostal nerve was an excellent size match and post-procedure necropsy yielded successful anastomoses without apparent complications. CONCLUSIONS: Robotic intercostal nerve grafting for reversal of thoracic sympathectomy is technically feasible. The robotic device allows the principles of neural microsurgery to be maintained and provides a minimally invasive option for reconstruction of the sympathetic chain.

Independent predictors for early and midterm mortality after thoracic surgery.

BACKGROUND: The purpose of the present study was to determine independent predictors for early and midterm mortality for the whole context of thoracic surgery. METHODS: We studied 1453 consecutive patients who underwent thoracic surgery between 2002 and 2005. Operations included lung resections (n = 504), mediastinal (n = 468), pleural and pericardial (n = 226), esophageal (n = 83), chest wall (n = 85), tracheal (n = 50) and other procedures (n = 37). Midterm survival data (mean follow-up 2.0 +/- 1.1 years) were obtained from the National Death Index. Multivariate logistic regression was used to assess in-hospital mortality. Independent predictors for midterm mortality were determined by multivariate Cox regression analysis. RESULTS: There were 47 (3.2 %) in-hospital and 312 (21.5 %) late deaths. Independent predictors for in-hospital mortality included Zubrod score (OR 2.72, P < 0.001), ASA score (OR 3.42, P < 0.001), pneumonectomy (OR 20.71, P = 0.001) and no history of cerebrovascular events (OR 0.27, P = 0.011). Independent predictors for midterm mortality included age (HR 1.03, P < 0.001), weight loss (HR 1.57, P = 0.005), Zubrod score (HR 1.47, P < 0.001), primary lung cancer (HR 1.98 P < 0.001), intrathoracic extrapulmonary metastases (HR 2.78, P < 0.001), primary chest wall tumor (HR 0.14, P = 0.008), diabetes requiring insulin (HR 1.71, P = 0.017), no preoperative renal failure (HR 0.57, P = 0.004), no comorbidities (HR 0.54, P = 0.009), ASA score (HR 1.69, P < 0.001), postoperative radiation treatment (HR 1.90, P = 0.016), pneumonectomy (HR 2.18, P = 0.040), reoperation for bleeding and/or postoperative transfusion (HR 3.10, P = 0.027) and postoperative pulmonary complications (HR 1.89, P = 0.013). CONCLUSIONS: We determined independent predictors for in-hospital and midterm mortality for the whole context of thoracic surgery. Zubrod and ASA scores affect both early and midterm mortality.

Prevention of aortic anastomotic hemorrhage. A simplified intraoperative testing technique.

BACKGROUND: Postoperative bleeding in aortic root aneurysms had represented a challenge. METHODS: Intraoperative testing of the annular or subannular aortic anastomosis, during procedures involving replacement of the aortic root, with either synthetic tube graft, a composite graft or an allograft is described. By reversing the flow of the LV vent and delivering cardioplegia into the left ventricle and thereby pressurizing the left ventricle and its outflow, this technique enables the surgeon to simulate the volume loaded heart, prior to completion of the distal anastomosis. A systematic assessment of the proximal suture line can then be undertaken. Portions of the proximal suture line, particularly the posterior aspect, are obscured if the inspection takes place after completion of both aortic anastomoses, the coronary attachments, as well as from the presence of the main pulmonary artery and by the distended aorta itself. RESULTS: The use of this method in 34 patients is described without untoward events related to this technique. CONCLUSIONS: The advantages of this technique are a rapid and safe assessment of the integrity of the proximal suture line bed.

Possible intra-aortic balloon pump "function-related" mechanism of embolic events in patient with protruding atheroma in the thoracic aorta.

A possible new functional mechanism of atheromatous embolus is presented resulting from reversed aortic blood flow during diastolic augmentation by balloon counterpulsation. This mechanism is different from mechanical disruption during insertion. Despite this, intra-aortic balloon remains an important asset in the management of hemodynamically challenged patients.

Early mortality and morbidity of bilateral versus single internal thoracic artery revascularization: propensity and risk modeling.

OBJECTIVES: We examined whether bilateral internal thoracic artery (BITA) revascularization is associated with any increased in-hospital mortality and complications compared with single internal thoracic artery (SITA) revascularization. BACKGROUND: Despite proven long-term benefits, BITA revascularization has been slow to be adopted because of fear of increased early morbidity. METHODS: We evaluated 1,697 consecutive patients undergoing BITA (n = 867) or SITA (n = 830) revascularization. We used propensity score analyses and adjusted risk models to address differences between arms. RESULTS: There were 20 (2.3%) deaths in the BITA group versus 26 (3.1%) in the SITA group (odds ratio 0.73, p = 0.30). Propensity analysis identified several parameters that affected the decision to use BITA. Adjusting for propensity score and all potential risk factors, the odds ratio for death with BITA versus SITA was practically 1. Bilateral internal thoracic artery revascularization did not increase the number of in-hospital complications with the possible exception of deep sternal wound infections (11 [1.3%] vs. 3 [0.4%], p = 0.057). In multivariate modeling BITA increased the risk of deep sternal wound infections only in emergent cases and in older patients; the excess risk was negligible among 1,206 patients (71.1% of total) who did not have emergent revascularization and were < or =70 years old (risk difference 0.3%, p = 0.74). There was no difference in length of stay after adjustment for propensity factors (mean 11.3 vs. 11.7 days, p = 0.66). CONCLUSIONS: Bilateral internal thoracic artery revascularization grafting confers no increased risk for early death and does not prolong hospital stay. The small increase in the risk of deep sternal wound infections does not affect the majority of patients.

Successful repair of myocardial free wall rupture after thrombolytic therapy for acute infarction.

BACKGROUND: Controversy exists regarding the timing of thrombolytic administration and rupture rate. METHODS: Hospital records at St. Luke's-Roosevelt Hospital of the 4 study patients were reviewed and compared with those of 41 patients from a group of 537 patients concurrently admitted with a diagnosis of myocardial infarction (MI). RESULTS: Four patients experienced ventricular free wall rupture after having a MI between November 17, 1993, and July 28, 1995. All received tissue plasminogen activator. In 1 patient, pericardial effusion associated with a pseudoaneurysm was discovered in the operating room. The 3 others developed clinical pericardial tamponade before surgery. All 4 patients survived and left the hospital on postoperative days 10, 11, 11, and 82, respectively. During this same time period, 537 patients were admitted with MI, 41 of whom died; the study's 4 patients were compared with these 41. CONCLUSIONS: These data demonstrate that rupture of the ventricular free wall can occur early after thrombolytic therapy and may have a subacute course. Prompt diagnosis and surgery offer excellent chances of surviving this fatal condition.

Communicating bronchopulmonary pancreatic foregut malformation.

Bronchopulmonary foregut malformations include intralobar and extralobar pulmonary sequestrations, bronchogenic cysts, and communicating bronchopulmonary foregut malformations (CBPFM). These malformations, formes frustes, originate as developmental abnormalities of ventral foregut budding of the tracheobronchial tree or the gastrointestinal tract. The communication's patency with the parent viscus determines if a contained malformation occurs, or if an abnormal communication persists as a CBPFM. This case demonstrates a unique example of a CBPFM in which the main pancreatic duct communicated with pulmonary parenchyma through a retroperitoneal fistula.

"Band aid" surgery: upper sternal split incision for valve surgery in adults. A modified technique.

A limited 10 cm upper sternotomy to the level of the third right intercostal space with preservation of the entire length of the left half of the sternum (quarter sternotomy) allows: 1) exposure for aortic valve surgery; 2) utilization of standard equipment and cannulation techniques; 3) preservation of both internal thoracic arteries and 4) early discharge from the hospital. Three patients, all female, aged 45, 62 and 67, two with severe aortic insufficiency and one with severe aortic stenosis, underwent replacement. In two, a St. Jude's valve and in one, a Baxter pericardial valve were used. In addition, aortic decalcification-endarterectomy was carried out in one and re-exploration in another. All patients were discharged at 4 days, impressed by their "Band-Aid Surgery". Improved patient mobility and earlier recovery of ventilatory function are possibly related to this more stable form of limited sternotomy.

A comparison of left ventricular performance indices measured by transesophageal echocardiography with automated border detection.

BACKGROUND: Automated border detection (ABD) allows semiautomated measurement of left ventricular (LV) areas. They can be combined with left ventricular pressure signals to generate pressure-area loops and pressure-dimension indices of contractility. This study compared conventional indices of ventricular performance (fractional area change [FAC] and circumferential fiber shortening [Vcfc]) with pressure-dimension indices of contractility. A secondary aim was to compare the effects of volatile anesthetics on the indices. METHODS: Using transesophageal echocardiography with automated border detection, FAC and Vcfc were obtained in 23 patients after cardiopulmonary bypass. Left ventricular pressures were obtained with a left ventricular catheter. Preload reduction by inferior vena caval occlusion was used to obtain end-systolic elastance (Ees), preload recruitable stroke force (PRSF), and dP/dtmax x EDA(-1) (EDA = end-diastolic area). In 11 patients, the measurements were repeated at 1 end-tidal minimum alveolar concentration of halothane or isoflurane. The results are expressed as mean +/- SD. RESULTS: After cardiopulmonary bypass, FAC was 31.1+/-7.9%, Vcfc was 0.6+/-0.2 circ x s(-1), Ees was 25.8+/-11.6 mmHg x cm(-2), PRSF was 60.8+/-26.6 mmHg, and dP/dtmax x EDA(-1) was 245+/-123.4 mmHg x s(-1) x cm(-2). At 1 minimum alveolar concentration of a volatile anesthetic agent, FAC, Vcfc, and dP/dtmax x EDA(-1) remained unchanged. Significant decreases in Ees (19%) and PRSF (28%) were observed. CONCLUSIONS: The association between pressure-dimension indices and Vcfc or FAC was weak or nonexistent. A reduction in myocardial contractility induced by the administration of volatile anesthetic agents was detected by Ees and PRSF, but not by FAC, Vcfc, or dP/dtmax x EDA(-1). After myocardial revascularization, Ees and PRSF appear more sensitive than FAC or Vcfc for measuring changes in contractility.

A late complication of tuberculous pericarditis after partial pericardial resection.

Tuberculous pericarditis is estimated to occur in 1% to 2% of cases of pulmonary tuberculosis. Despite adequate therapy, a subset of patients may eventually require pericardiectomy. Incomplete pericardial resections are associated with an increased incidence of late complications. We report a cutaneous sinus tract communicating with residual pericardium and a retrosternal abscess cavity 11 years after partial pericardial resection.

A case of massive thymolipoma.

A massive anterior mediastinal tumor was discovered in a 9-year-old girl with long-standing symptoms of asthma. Preoperative computed tomography (CT) scan and magnetic resonance imaging (MRI) results suggested the presence of a thymolipoma, a rare benign tumor of the thymus. Few cases have been reported in the literature, although the histological and radiographic features have been well described. This case confirms previously reported characteristics and also illuminates new aspects of clinical presentation and perioperative management.

Pre-clamp cardioprotection by protein kinase C (PKC) inhibitor improves left ventricular function following canine normothermic arrest.

Since protein kinase C (PKC) has been proven to be a mediator of neutrophil activation and of intracellular calcium homeostasis, its inhibition could protect the myocardium from the deleterious effects of ischemic/reperfusion inury (IRI). The principal objective of this study was to evaluate the efficacy of the PK inhibitor SPC-100270 (2S,3S)-2-amino, 3-octadecanediol in a canine model of IRI. A double-blind study was conducted in which 19 coonhound dogs received either SPC-100270 or a vehicle before going on cardiopulmonary bypass (CPB). After 60 minutes of global normothermic (37 degree C) cardiac arrest (cross-clamp time 65-81 minutes for SPC-100270 and 65-72 minutes for control) and discontinuation of CBP, an epicardial short axis view echocardiogram was performed and reviewed by a double-blinded observer to determine the ejection fraction (EF). EF value exceeded 20% in 5 out of 9 SPC-100270 animals (27%-44%) and in 0 of 10 controls (0%-16%). These data show that SPC-10027 significantly (p=0.01 by Fisher's Exact Test) increased the probability that the animals would exhibit an EF greater than 20%.

Concurrent right atrial myxoma and malignant lymphoma.

Atrial myxomas are the most common primary tumor of the heart. We report an unusual case where an incidentally found right atrial myxoma was associated with a malignant lymphoma. Surgical management of the concurrent problems is discussed as well as a review of pertinent literature and efficacy of diagnostic modalities.

Initial clinical experience with rectus sheath grafts in congenital heart defects.

This study reports on the initial clinical experience using anterior rectus sheath as potentially growing graft material in congenital heart lesions. The first seven patients with complex congenital lesions requiring a rectus sheath graft because of inadequate available pericardium are reviewed. The initial operations were: TOF (unicusp pulmonary valve) (re-op), two Konno procedures (one VSD and one RV patch), two arterial switch procedures for TGA (neoaortic augmentation), two Fontan (re-op) atrial augmentation patch and pulmonary arterioplasty (re-op). Ages ranged from 1 week to 15 years. Follow-up ranged from 1 to 72 months and included open visual inspection at reoperation in 5 cases, angiography in 3 cases, and echocardiography in 4 cases. One early respiratory death occurred in the fourth postoperative week. So far no early bleeding from rectus sheath patches, infection, aneurysmal dilatation, or scar contraction was observed. No manifestation of peripheral emboli was seen. Hernias of the harvest site were absent. We concluded that in absence of pericardium and in areas where future cicatrization or aneurysmal dilatation is undesirable, anterior rectus sheath appears to be a reasonable alternative.

Multiple aneurysms of the internal thoracic artery.

Nontraumatic aneurysms of the internal thoracic artery are rare. We report a case where multiple aneurysms of the right internal thoracic artery presented as an asymptomatic density on the chest radiograph. Operative findings and pathology are reviewed.

Inflammatory aneurysm of the ascending aorta; an unreported entity.

A 69-year-old woman with an enlarging ascending aortic aneurysm is presented. At operation, the patient was noted to have extensive peri-aneurysmal fibrosis and inflammation with a 1 cm thick aneurysm wall. Pathologic examination was consistent with inflammatory aneurysm. Inflammatory aneurysms of the thoracic aorta are uncommon and this may be the first patient with this process involving the ascending aorta with both operative and pathologic findings.

Transmural myocardial infarction with coexisting critical aortic stenosis as an etiology for early myocardial rupture.

Myocardial rupture is the most important cause of post-infarct sudden death after myocardial infarction other than shock and dysrhythmias. Usually unrecognized, pseudoaneurysm formation is a delayed consequence of myocardial rupture in a small portion of patients who will remain at high risk for late rupture and death. Clinical studies have defined a profile of the patient who is at increased risk for post-infarct myocardial rupture. We believe that an additional factor, ventricular outflow tract obstruction, may add to the risk of having a post infarct rupture. A high degree of suspicion by the clinician accompanied by the timely performance of diagnostic tests may help to decrease the mortality from this catastrophic event.