Preoperative cardiac evaluation of lung resection candidates

Patients who have lung cancer typically have both pulmonary and cardiac disease as a result of cigarette smoking and are potentially at increased risk for perioperative cardiopulmonary complications. Knowledge of risk factors and a careful preoperative assessment will help the medical team stratify the patient's level of risk and employ measures to minimize surgical risk. The available literature specific to cardiac risk and lung cancer surgery is minimal, but the general principles of preoperative cardiac risk evaluation and perioperative management have been reviewed. When considering cardiac testing and interventions, the medical consultant must remember that surgery is the treatment of choice for non-small cell lung cancer and must avoid any excessive delay that might compromise the patient's chance of a surgical cure.     

Prediction of postoperative exercise capacity in lung resection candidates

The relation between submaximal oxygen consumption (MVO2) before and after lung resection was studied, and the possibility to predict postoperative MVO2 was investigated. Thirty four patients (19 lobectomies, 9 bi-lobectomies, 6 pneumonectomies) performed exercise tests one week before operation and at the time when they were able to resume work daily after operation (in two to eleven months). Predicted postoperative MVO2 was calculated from preoperative MVO2 as follows: 0.8 x resection rate x age index x preoperative MVO2 + 183. In this formula the resection rate means [the number of total lung segments--the number of non-working segments]. The age index is 1.5 for patients under 50 years, 1.0 for those between 50 to 69, and 0.8 for those over 70. This predicted MVO2 had strong correlation with actual postoperative MVO2 (r = 0.94, t = 13.4, y = 1.08x - 83) in twenty five patients. Correlation was low in the remaining nine patients, however. The nine had old myocard infarction, postoperative cerebral infarction, marked wet lung, anticancerous chemotherapy within ten days or marked reduced exercise capacity (below 3 METS at maximal exercise). From these results, we concluded it is possible to predict the postoperative MVO2 using preoperative MVO2 except in cases which have some exercise limiting factors or whose exercise capacity is very small.     

Technical evaluation of video-assisted lung resection for lung cancer

There are two major problems including indications and techniques in video-assisted lung resection for lung cancer. The current technique of video-assisted lung resection have various troublesome procedures as compared with conventional open thoracic surgery. We have designed a new thoracoscopic instrument as a ligation device. Between September 1997 and August 1999, 15 patients with early lung cancer underwent video-assisted lobectomy (VAL). In 5 patients, VAL was performed through skin incisions of 3 cm using this new device and at extraction of the resected lung the skin incision was elongated minimally (Group A). In 10 patients, a skin incision of 6-8 cm was made enough to perform VAL without the new device at the beginning of the operation (Group B). Total length of skin incisions (TLS) and total postoperative pleural discharge (TPD) were measured. TLS was 7.2 +/- 1.47 cm in group A, 11.9 +/- 4.50 cm in group B (p = 0.029). TPD was 492 +/- 256 ml in group A, 1.132 +/- 591 ml in group B (p = 0.032). TPD might be thought as an index of invasion of VAL and it was difficult to decrease TPD significantly. The new device made it possible to feel the ligature tension when the device was in touch with the chest wall. In a result, the device improved technical procedure of VAL and contributed toward less invasive surgery.     

Determination of operability in candidates who undergo lung resection for bronchogenic carcinoma

In this prospective study the authors attempted to determine the effect of lung resection for bronchogenic carcinoma on final pulmonary function in patients who had severe limitation of lung air flow preoperatively and were therefore likely to have severe, progressive pulmonary failure and in those who had acceptable pulmonary function preoperatively. Preoperative and postoperative pulmonary function tests were performed on 20 patients chosen to undergo various types of resection for bronchogenic carcinoma. Those who underwent pneumonectomy had changes in lung volume that were expected for a resection of that magnitude. Patients who underwent lesser resections had more variable postoperative lung volumes and flows. The patients whose preoperative pulmonary function was poorest had the least change postoperatively and even, in some cases, showed some improvement in function, yet they were the ones most likely to be denied surgery, because of their poor preoperative pulmonary function.     

Role of pulmonary vascular resistance measurements in preoperative evaluation of candidates for pulmonary resection

Pulmonary function tests (PFT), arterial blood gases (ABG), lung scanning, and pulmonary artery balloon occlusion with measurement of pulmonary vascular resistance (PVR) have all been used for preoperative evaluation of pulmonary function. These tests, however, do not always accurately predict tolerance to lung resection. We have evaluated a new technique which promises to increase the accuracy of preoperative evaluation of pulmonary function. Utilizing a balloon flotation catheter, we measured PVR at varying cardiac outputs. Forty-five patients underwent this study without morbidity or mortality. Five of 30 patients who subsequently underwent pulmonary surgery died of respiratory failure. All of these deaths were from the high-risk group as determined by PVR. Only one of the five had been judged to be at high risk by PFT and ABG. This technique has the advantages of low morbidity and simplicity and should be especially helpful in the evaluation of those patients who have borderline pulmonary function as determined by the more standard tests.     

Review and evaluation of limited resection for early lung cancer

Limited resection for early lung cancer has been associated with significantly higher local recurrence rates based on previous reports such as those from lung cancer study groups. On the other hand, a few groups demonstrated that patients with small peripheral cancer who undergo limited resection have comparable survival rates with those who undergo lobectomy. Recent advances in radiologic investigation and pathologic analysis have broadened the indications for limited resection. Since the introduction of the adenocarcinoma classification by Noguchi surgery for localized bronchioloalveolar carcinoma has focused on limited resection. Caution is necessary when performing wedge resection even if 10 mm or less in diameter and in compromised segmentectomy for early lung cancer. Although limited resection is still controversial intentional segmentectomy for localized bronchioloalveolar carcinoma or less than 20 mm or less in diameter may be recommended without evidence-based medicine. It is important to accumulate further evidence clarifying the survival and function benefits of limited resection. New therapeutic modalities for limited surgery for small-sized lung cancer may increase patient life expectancy.     

Physiologic sufficiency of regenerated lung lymphatics.

The physiologic sufficiency of regenerated lung lymphatics after surgical transection of the lung hilum was studied experimentally. Dogs were prepared by surgical interruption of all left lung hilar tissues and structures except the skeletonized pulmonary artery and the pulmonary veins; continuity of the bronchus was restored by anastomosis. Anatomic reconnection of lung lymphatics to mediastinal lymph vessels was determined by injecting a sky blue dye marker into peribronchial tissues distal to the bronchial anastomosis at different intervals after surgical preparation. From a series of 50 experimental animals it was demonstrated that the surgical procedcure interrupted lymphatic drainage and that anatomic reconnection with mediastinal lymphatics developed 7-28 days after preparation. Physiologic sufficiency of regenerated lymphatics was studied in 60 animals by rapid intravascular volume expansion as a test of lymph flow capacity. By gravimetric determination of lung water and histologic examination of lung specimens this study revealed a significant incapacity to maintain lung water homeostasis 3 days after preparation with return toward normal lymph flow capacity 35 days after preparation. This study indicated that lung lymphatic drainage is re-established 7--28 days after surgical interruption and becomes relatively sufficient after 35 days.     

Home monitoring for lung transplant candidates

Home monitoring by lung transplant recipients has been effective for early detection of clinical problems. This study used an electronic diary for home monitoring by lung transplant candidates to improve communication between candidates and the transplant team. Candidates were randomized into control (52 subjects following standard telephone reporting procedures) and intervention (67 subjects using an electronic diary to record and transmit a range of health-related measures) groups. Outcome measures were monitoring adherence and level of communication (for monitor acceptability and utilization), hospital length of stay after transplantation and survival at 4 months (for clinical effectiveness). Subjects used the diary without difficulty and with good adherence. Subjects and coordinator contacts were similar between groups; intervention group subjects were positive regarding contact based on diary use. There were no significant differences in clinical outcomes between groups. Changing diary questions might improve the effectiveness of electronic monitoring for lung transplant candidates.     

Pretransplant evaluation of renal transplant candidates

Kidney transplantation should be strongly considered for all medically suitable patients with chronic and end-stage renal disease (ESRD). Improvements in outcomes after renal transplantation have resulted in a more liberal selection of patients. High-risk category patients including human immunodeficiency virus (HIV)-positive, highly sensitized patients, T-cell positive cross-match, and ABO blood group-incompatible patients are now considered potential renal transplant candidates. Unfortunately, the demand for kidney transplants far exceeds the supply of available organs, causing a persistent increase in the number of patients on the waiting list with a parallel increase in the waiting time for a cadaveric kidney transplant. This has 2 major consequences. First, patients on the waiting list are getting sicker and older. Second, living donors have assumed increasing importance in renal transplantation. Pre-existing morbidities including malignancies, cardiovascular disease, infections, and coagulopathies should be extensively evaluated before proceeding to transplantation. Special attention should be given to cardiovascular risk factors because the leading cause of death after renal transplant is cardiovascular disease. A full immunologic evaluation with ABO blood group determination, human leukocyte antigen (HLA) typing, screening for antibody to HLA phenotypes, and cross-matching need to be gathered before transplantation to avoid antibody-mediated hyperacute rejection or to proceed with specific protocols in highly sensitized or in positive T-cell cross-match patients. With the increased rate of donation from living donors, regular follow-up evaluation of kidney donors is recommended to detect hypertension or proteinuria in those who may develop it.     

Late reintervention with lung resection following earlier lung resection

14 reoperations with lung resection for a recurrent tumour, metastasis or second malignant disease were performed in patients with lung resection for bronchial carcinoma (6 patients), solitary metastasis of hypernephroma (3 patients), and lung resection for tuberculosis (5 patients). The following patients were operated on the second time, viz. for cancer (2 patients), tuberculoma (1 patient), chondroma (1 patient), and haemangiopericytoma in the remaining lung after pneumonectomy (1 patient). There was a simultaneous cancer in 2 patients reoperated for malignant diseases. 2 patients died 12 or 21 months after resection, all the others are still alive 2 to 6 years after the second operation.     

Physiologic aspects in human lung transplantation.

Heart-lung transplantation (HLT), followed by single lung transplantation (SLT) and subsequently bilateral lung transplantation (BLT) have been developed as treatments for patients with end-stage pulmonary diseases. Initially, SLT was limited to idiopathic pulmonary fibrosis (IPF) cases and thought to be contraindicated not only for infectious diseases, but also for non-infectious diseases, including pulmonary emphysema (PE) and primary pulmonary hypertension (PPH), based on physiologic points of view. However, SLT is now widely performed for those non-infectious diseases and most of the recipients return to a normal active life. It is quite possible that BLT is superior to SLT in terms of pulmonary function, and it has been reported that BLT is better for PE and PPH patients in regards to perioperative course, postoperative exercise capacity, and long-term survival. For those situations and because of the present scarcity of donor organs, SLT must be utilized for selected non-infectious diseases for which it is safe and effective. When a single lung is replaced for IPF, PE, and PPH recipients, different physiologic situations are produced postoperatively, the understanding of which is extremely important to achieve good results, not only in the perioperative but also in the long term.