[Phrenic nerve stimulation in biventricular cardiac pacemakers]. / N.-phrenicus-Stimulation bei biventrikulären Schrittmachern. Stufenschema zum intraoperativen Vorgehen.

BACKGROUND: Phrenic nerve stimulation (PNS) complicates the positioning of the left ventricle lead. We present a step-by-step approach to correct PNS during implantation, as established in our daily routine. METHODS: The incidence of PNS, its successful correction, and long-term results (median 27 months) were analyzed retrospectively in 266 lead positions. RESULTS: Phrenic nerve stimulation occurred in 13.9% of the lead positions. Multivariate analysis (P<0.02) showed that PNS only depended on the place of stimulation (coronary sinus side branch). Lead type, CRT indication, and patient's sex had no significant correlation. Following the step-by-step approach presented here, PNS was corrected satisfactorily in all cases. CONCLUSIONS: Approach in case of PNS: 1. push or pull the lead within the same vein, 2. change to a different vein, 3. maintain position in case of a safe distance between the phrenic nerve and the pacing threshold, 4. change the lead type to achieve stable anchorage at adequate positions, 5. use a device featuring electronic repositioning.

Interpretation of the results of Doppler ultrasound flow volume measurements of infrainguinal vein bypasses.

OBJECTIVES: To evaluate a pattern for the interpretation of the results of intraoperative Doppler ultrasound flow volume measurement of infrainguinal vein bypasses. DESIGN: Retrospective analysis of prospective data. MATERIALS: 91 consecutively performed infrainguinal non-reversed free vein bypasses. METHODS: Using preoperative angiograms, the run-off, which can be expected after the reconstruction, was evaluated by means of a point score. A first measurement of the flow volume was taken after the release of the blood flow and a second after administration of 20 mg Alprostadil into the bypass. From these two results, we calculated an average value, which was set in relation to the run-off score. From this we computed a relative flow, i.e. the flow per open crural vessel = per run-off score unit (quotient:flow/score). RESULTS: The median relative flow of angiographically perfect reconstructions was 86 ml/min. In 14 reconstructions, the control angiogram showed stenoses: median relative flow 59 ml/min, range between 20 and a maximum of 75 ml/min. The practical application of the flow measurement requires a minimum relative flow guideline for stenosis-free reconstructions. A guideline of 80 ml/min would yield a sensitivity of 100% and a specificity of 68%. CONCLUSIONS: Measurement of flow volume could be used as a screen, in order to filter out reconstructions, which must be further clarified with an angiogram. A further prospective evaluation of the value of volume flow is needed before any conclusive recommendations can be drawn.

Retrosternal pedicled jejunum interposition: an alternative for reconstruction after total esophago-gastrectomy.

OBJECTIVE: If the colon cannot be used for reconstruction after total esophago-gastrectomy, alternatives have to be sought. METHODS: From 1990 to 2001, retrosternal jejunum loop interposition was performed in 35 patients (male/female: 29:6; mean age 59.2, range 16-83 years) due to cancer in 32 cases and to esophageal perforation in three cases. In all patients reconstruction with stomach or colon, respectively, was impossible on behalf of the underlying histology, of previous resection of the stomach and impedient colonic diseases. A jejunal segment with abundant arcades was chosen, preserving a strong, distal arteriovenous mesenteric pedicle, while 2-3 proximal mesenteric vessels were severed. The loop was pulled up retrosternally, establishing a cervical end-to-side esophagojejunostomy. A Roux-en-Y anastomosis was done in a convenient position. RESULTS: Two patients died perioperatively due to mediastinitis and consecutive multiorgan failure (one Boerhaave's syndrome, one suicidal ingestion of acid). In one case the oral part of the loop developed venous congestion and was replaced by a free jejunal transplant. The perioperative course of 32 patients was uneventful. Seventeen patients are up and well (1-8.5 years). Sixteen patients died of metastatic disease. The functional results are satisfactory. In about 50% of patients recurrent dilatations became necessary due to anastomotic scars. However, none of the patients complained about severe dysphagia. CONCLUSION: In cases of impedient colonic diseases, the pedicled, retrosternal jejunal loop with cervical anastomosis is an alternative for reconstruction after total esophagogastrectomy.

Stress-induced hormonal and mood responses in scuba divers: a field study.

The majority of injuries in scuba-divers are attributable to inappropriate behavior under stressful diving conditions, predominantly involving panic reactions emerging from elevated levels of anxiety. Divers with an elevated level of anxiety and poor coping are at higher risk of developing panic reactions than those possessing more adequate stress-coping-mechanisms. In the comparison of two extreme groups of seven divers each with opposite stress coping strategies, prolactin was found to be a hormonal marker with a significant increase in the sub-group of the stress-controllers. This hormonal response was observed in a recreational and a stressful dive, and in the latter with a more distinct elevation. Along with the self-reported emotional conditions under immersion, these data suggest that an increased prolactin level reflects a state of elevated physical and mental activation and vigilance. Facing a stressful situation subjects with more emotional concern and the tendency to surrender react by "blunted responses" and show significantly lower elevations of the prolactin levels in contrast to subjects with the very opposite psychological features. The other observed somatic parameters (epinephrine, norepinephrine) showed significant increases during and after dives (with the exception of saliva cortisol), however without any significant group difference.

Thoracic wall reconstruction using both portions of the latissimus dorsi previously divided in the course of posterolateral thoracotomy.

OBJECTIVE: Besides other factors, the choice of reconstructive method for full thickness thoracic wall defects depends on the morbidity of preceding surgical procedures. The pedicled latissimus dorsi flap is a reliable and safe option for reconstruction of the thorax. A posterolateral thoracotomy, however, results in division of the muscle. Both parts of the muscle can be employed to close full thickness defects of the chest wall. The proximal part can be pedicled on the thoracodorsal vessels or the serratus branch; the distal part can be pedicled on paravertebral or intercostal perforators. This retrospective study was undertaken to evaluate the reconstructive potential of both parts of the latissimus dorsi in thoracic wall reconstruction after posterolateral thoracotomy. METHODS: Between 1987 and 1999, 36 consecutive patients underwent reconstruction of full-thickness thoracic wall defects with latissimus dorsi-flaps after posterolateral thoracotomies. The defects resulted from infection and open window thoracostomy (n=31), trauma (n=3) and resection of tumours (n=2). The patients' average age was 57 years (range 22-76 years). Twenty-five patients were male, 11 were female. In 31 cases the split latissimus dorsi alone was employed; in five cases additional flaps had to be used due to the size of the defects, additional intrathoracic problems or neighbouring defects. RESULTS: In 34 cases defect closure could be achieved without major complications. Empyema recurred in the pleural cavity in one case and one patient died of septicaemia. The 15 patients who had required a respirator in the preoperative phase could be extubated 4.8 days (average) after thoracic wall reconstruction. Postoperative hospital stay averaged 16 days. CONCLUSIONS: Different methods are available for reconstruction of full thickness defects of the thoracic wall. After posterolateral thoracotomy in the surgical treatment of empyema, oncologic surgery and traumatology, the latissimus dorsi muscle still retains some reconstructive potential. Advantages are low additional donor site morbidity and anatomical reliability. As it is located near the site of the defect, there is no need for additional surgical sites or intraoperative repositioning. In our service, the split latissimus dorsi muscle flap has proven to be a valuable and reliable option in thoracic wall reconstruction.

Management of iatrogenous esophagus perforation.

OBJECTIVES: The management of patients with iatrogenous, instrumentally caused esophageal disruptions is still a controversially discussed challenge for any physician. We reviewed indications, morbidity, and mortality of esophagectomy compared to less aggressive treatment schemes in the light of our single-unit experience. PATIENTS AND METHODS: We reviewed the cases of 38 consecutive patients suffering from iatrogenous esophageal disruption treated within the last 10 years at the University Medical School Graz. RESULTS: Severe sepsis was diagnosed in seventeen patients; fourteen of the seventeen patients were treated by esophagectomy followed by primary or secondary reconstruction at a mortality rate of 28.6 % (four of fourteen patients). All fourteen patients thus treated had major preexisting esophageal pathologies. In three of the total seventeen cases reviewed, conservative treatment modalities were used. The mortality rate in the non-septic group treated by direct suturing (n = 21) was 4.8 % (one of twenty-one patients). Major preexisting esophageal pathology was present in thirteen. The overall mortality was 13.2 % (five of thirty-eight patients). CONCLUSION: The strategy of primary repair for iatrogenous esophageal injury should only be adopted in patients with minor or without intrinsic esophageal disease, and in the absence of severe sepsis suggesting mediastinitis. Severe sepsis following iatrogenous esophageal trauma should prompt the decision for esophagectomy where anatomically and/or oncologically possible.

Does new photosensitizer improve photodynamic therapy in advanced esophageal carcinoma?

BACKGROUND AND OBJECTIVE: Polyhematoporphyrin (Photosan) as sensitizers for photodynamic therapy (PDT) in advanced esophageal cancer carry the risk of prolonged photosensitivity of the skin. New sensitizers such as 5-aminolaevulinic acid (ALA) with low rates of skin phototoxicity appear to be promising alternatives. The aim of this study was to evaluate the efficacy of ALA compared to Photosan for PDT in advanced esophageal carcinoma regarding phototoxicity of the skin, reduction of dysphagia, tumor stenosis, and tumor length and Karnovsky performance status. STUDY DESIGN/MATERIALS AND METHODS: After diagnostic work-up, photosensitization was done in 22 patients with ALA (60 mg/kg body weight, oral, 6-8 hours prior to PDT) and in 27 patients with Photosan (2 mg/kg body weight, i.v., 48 hours before PDT). The light dose was calculated as 300 J/cm fibre tip. Light at 630 nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 absolute atmospheric pressure. RESULTS: Improvement regarding dysphagia, stenosis diameter, and tumor length could be obtained in both treatment arms with a significant difference in favour of the Photosan-group, P = 0.02; P = 0.0000; and P = 0.000014, respectively. The Karnovsky performance status also improved in both groups and showed no significant difference (P = 0.12). The median survival time for the ALA-group was 8.0 months, compared with 9.0 months for the Photosan group. No sunburn or other major treatment related complication occurred in both treatment arms. Thirty-day mortality was 0%. CONCLUSION: Despite the limitations of a non-randomized study, photosensitzation with Photosan seems to be more effective in PDT of advanced esophageal carcinoma compared to ALA.

Intradermal injection vs. oral treatment of tinnitus.

Local pharmacological intradermal infiltration is a therapy being used more and more thanks to the positive results achieved, particularly for all those therapies acting on the microcirculation. In trying to better the results obtained with medical therapy for tinnitus sufferers, to assess the effect of a vasoactive drug, the method of administration by the intradermal route, which allows a strengthening of the pharmacological effect, has been added. The present study comprised 120 tinnitus sufferers who underwent intradermal auricle infiltration with a vasoactive drug. The control group includes 115 tinnitus sufferers who underwent systemic vasoactive therapy with the same drug. Forty-five days after beginning intradermal treatment the symptom improved and continued to do so following further infiltrations which patients underwent every 15 days. In the control group we noticed a moderate improvement 45 days after the beginning of oral therapy; thereafter the results reached a plateau by the 60th day. Intradermal vasoactive therapy for idiopathic tinnitus seems to be a new success, which will be an interesting progression in the therapy of this kind of symptom.

Boerhaave's syndrome: a continuing challenge in thoracic surgery.

BACKGROUND/AIMS: Boerhaave's syndrome accounts for 30-40% of esophageal disruption. The current literature regarding the management of these patients and problems in treatment remains controversial. METHODOLOGY: Between 1988 and 1998, 14 patients with Boerhaave's syndrome were treated in our unit. Five primary repairs and 9 esophagectomies were performed. A retrospective review of these patients' records was carried out. The patients were divided into two groups. Group I: minor esophageal leak, local mediastinitis and hyperdynamic septic shock. All 5 cases were treated by primary repair. Group II: moderate to severe esophageal leak, severe mediastinitis and hypodynamic septic shock. All 9 cases were treated by transthoracic esophagectomy. RESULTS: Group I: No postoperative mortality. The mean ICU stay was 4.6 days. The mean hospitalization time was 14 days. Group II: The postoperative mortality was 22.2%. The mean ICU stay was 28 days. The mean hospitalization time was 45 days. CONCLUSIONS: The choice of which operative approach should be made in patients with Boerhaave's syndrome requires critical assessment of the patient's overall status, the duration of leak and the extent of mediastinal and pleural contamination.

Photosensitization with hematoporphyrin derivative compared to 5-aminolaevulinic acid for photodynamic therapy of esophageal carcinoma.

BACKGROUND: Hematoporphyrin derivatives (HpD) as sensitizers for photodynamic therapy (PDT) in advanced esophageal cancer carry the risk of prolonged photosensitivity of the skin. New sensitizers such as 5-aminolaevulinic acid (ALA) with low rates of skin phototoxicity appear to be promising alternatives. The aim of this study was to evaluate the efficacy of ALA compared with HpD for PDT in advanced esophageal carcinoma regarding phototoxicity of the skin, reduction of dysphagia, tumor stenosis and length, and Karnovsky performance status. METHODS: After diagnostic workup, photosensitization was done in 22 patients with ALA (60 mg/kg body weight, oral, 6 to 8 hours before PDT) and in 27 patients with a hematoporphyrin derivative (2 mg/kg body weight, intravenously, 48 hours before PDT). The light dose was calculated as 300 J/cm fiber tip. Light at 630 nm was applied using a pumped dye laser. In both groups, additional hyperbaric oxygenation was applied at a level of 2 absolute atmospheric pressure. RESULTS: Improvement regarding dysphagia, stenosis diameter, and tumor length could be obtained in both treatment arms with a significant difference in favor of the HpD group (p = 0.02; p = 0.0000; and p = 0.000014, respectively). A questionnaire of patients in the HpD group confirmed that the ability of swallowing a meal was superior compared with the discomfort from limitation to sun exposure. No sunburn or other major treatment-related complication occurred in both treatment arms. CONCLUSIONS: Despite the limitations of a nonrandomized study, photosensitzation with HpD seems to be more effective in PDT of advanced esophageal carcinoma compared with ALA.

Successful endoscopical sealing of malignant esophageotracheal fistulae by using a covered self-expandable stenting system.

OBJECTIVE: Any treatment of tracheo-esophageal fistulae in end-stage malignant stenosis of the esophagus must be weighed against associated morbidity and mortality. In a prospective study we investigated benefits and risks of the use of one type of coated, self-expandable stent. PATIENTS AND METHODS: We treated four male and two female patients, (mean age 68.3 years, range: 38-90 years), with malignant esophago-tracheal fistula non-resectable due to advanced tumour stage and/or functional reasons. All were in a poor general condition suffering from aspiration pneumonia and malnutrition. Four out of the six patients had had one or multiple extra- or endoluminal palliative treatments at a mean interval of 191 days (range: 7 days-15 ms) since the last intervention. The fistulae were sealed by using a covered, self-expandable stent (ULTRAFLEX esophageal stent system, Microinvasive, Boston Scientific Corporation, Boston, MA). RESULTS: Stenting did not cause any technical problems and all fistulae were successfully sealed in a one-step procedure. The median hospital stay was 4.6 days (range: 3-9 days). Except for one late stent induced recurrent fistula treated by re-stenting and tracheostomy, we did not observe any stent associated complications. Five patients died of tumour generalization. The median survival of the patients who died was 78 days (range: 35-129 days). One patient is alive and well at 120 days after stenting. CONCLUSION: In spite of the small number of patients the results suggest that this type of stent represents a safe and efficient approach for palliative endoscopic treatment of this high risk group. Local pretreatment does not preclude the successful use of the self-expandable coated stent.

Acid-related diseases following retrosternal stomach interposition.

BACKGROUND/AIMS: Esophagectomy and reconstruction with retrosternal stomach interposition implies bilateral truncal vagotomy, which supposedly causes gastric functional impairment. METHODOLOGY: Esophagectomy and reconstruction with retrosternal stomach interposition was performed on 15 men (mean age: 58.4 years) and 3 women (mean age: 43.6 years). The stomach was pedicled on the right gastric and right gastroepiploic artery without performing pyloroplasty. The cervical side-to-end anastomosis was sutured manually. The functional results were assessed 2-4 years postoperatively, by determining 24-hour qualitative intragastric pH-measurement, fluoroscopical gastric emptying studies, fasting gastrin levels, and endoscopy with biopsy studies. RESULTS: Endoscopy and biopsy confirmed esophagitis in 12 patients, gastritis in 15 and a gastric ulcer in 1 case. Fluoroscopic examination documented a normal passage of contrast medium in 17, slight impairment in 1 case treated by balloon dilatation of the pylorus. Qualitative intragastric pH-measurement revealed a total pH < 3 in 22.5-98.05% of measuring events (mean: 74.31%) within 24 hours, in 18 cases. Only 4 patients had pH < 3 in less than 50%. Fasting gastrin levels (normal range: 25-110 mU/L) varied from 48.78 mU/L-168.20 (mean: 85.23 mU/L). Only 3 patients had levels > 110 mU/L (maximum: 168.20 mU/L). CONCLUSIONS: Acid-related diseases may also occur after truncal vagotomy and retrosternal stomach interposition. Routine follow-up endoscopy and biopsy studies should be done to prevent inflammatory complications and maintain the patient's quality of life.

Indications for surgery in tracheobronchial ruptures.

OBJECTIVE: Ruptures of the tracheobronchial tree present a life-threatening situation. Nevertheless, therapy is still controversial. Though conservative treatment by antibiotics and intubation with the cuff inflated distal to the tear is favored by some authors, surgical repair is unavoidable in many cases. METHODS: We present a series of 31 patients (mean age 43.6 years, range 8--72 years) with iatrogenous or post-traumatic tracheobronchial ruptures treated since 1975. Fifteen ruptures were longitudinal tears of the trachea, not extending lower than a distance of 3 cm from the bifurcation, 11 involved the bifurcation and/or the main bronchi. The total length of the longitudinal tears ranged from 2 to 12 cm, five were transverse near complete abruptions of the trachea or main bronchi. Involvement of the full thickness of the wall with free view into the pleural space or to the esophageal wall was present in 29 cases. Twenty-nine out of the 31 patients underwent surgical repair and two were treated conservatively. The length and depth of the lesion, the degree of subcutaneous emphysema, pneumothorax and/or pneumomediastinum as well as clinical signs suggesting incipient mediastinitis were considered when making the decision for surgery. RESULTS: Twenty-five out of the 29 patients experienced an uneventful recovery. Four patients died of sepsis unrelated to the tracheobronchial trauma. One of the two patients who underwent conservative therapy also recovered uneventfully. The other one died because of multi-organ failure due to underlying myocardial infarction. CONCLUSIONS: Conveniently localized short lacerations, especially if they do not involve the whole thickness of the tracheal wall, can be treated with antibiotics and intubation with the cuff inflated distal to the tear, avoiding high intra-bronchial pressures also after eventual extubation. In all other cases surgical repair is to be preferred.

Acute effects of combined photodynamic therapy and hyperbaric oxygenation in lung cancer--a clinical pilot study.

BACKGROUND AND OBJECTIVE: Photodynamic tumor therapy (PDT) is based upon a photochemical reaction that is limited by the availability of molecular oxygen in the target tissue. The use of hyperbaric oxygenation (HBO) increases the amount of oxygen available for the process may thereby enhance the efficacy of PDT. We investigated the acute effects on tumor stenosis after combined PDT/HBO. PATIENTS AND METHODS: Thirty patients (22 males, 8 females, mean age: 68.8 years; range: 44-78 years) with inoperable non-small cell bronchogenic carcinoma and endobronchial stenosis were studied prospectively. Photosensitization was carried out using a hematoporphyrin-derivative 2 mg/kg BW 48 hours prior to PDT. The light dose was calculated as 300 J/cm fiber tip. The assessment of outcome 1 and 4 weeks after PDT/HBO was performed by endoscopy, chest X-ray, spirometry, laboratory parameters, subjective report of dyspnea, and Karnofsky performance status. RESULTS: At one and four weeks after the treatment, the patients felt a significant improvement of dyspnea and hemoptysis along with an objective subsiding of poststenotic pneumonia, though spirometric parameters revealed no significant difference. A significant reduction of tumor stenosis (P < 0.05) and an improvement of the Karnofsky performance status (P < 0.05) were documented 1 and 4 weeks after PDT/HBO. No therapy related complications were observed. CONCLUSIONS: Although the small number of patients does not allow to draw definitive conclusions to be drawn, the results suggests that combined PDT/HBO represents a new, safe, and technically feasible approach. It enables efficient and rapid reduction of the endoluminal tumor load and helps conditioning the patient for further treatment procedures.

Photodynamic therapy enhanced by hyperbaric oxygen in acute endoluminal palliation of malignant bronchial stenosis (clinical pilot study in 40 patients).

OBJECTIVES: Photodynamic tumor therapy (PDT) is based upon a photochemical reaction that is limited by the availability of molecular oxygen in the target tissue. The use of hyperbaric oxygenation (HBO) increases the amount of oxygen available for the process may thereby enhance the efficacy of PDT. We proved in a prospective, non-randomized clinical pilot study the acute effects on malignant bronchial stenosis and the technical feasibility of combined PDT/HBO. METHODS: Forty patients (29 males, 11 females, mean age: 64.3 years; range 39-82 years) with inoperable, advanced malignant bronchial tumor stenosis were studied prospectively. Photosensitization was carried out using a hematoporphyrin-derivative 2 mg/kg bw 48 h prior to PDT. The light dose was calculated as 300 J/cm fiber tip. The assessment of outcome 1 and 4 weeks after PDT/HBO was done by endoscopy, chest X-ray, spirometry, laboratory parameters, subjective report of dyspnea and Karnofsky performance status. RESULTS: At 1 and 4 weeks after the treatment the patients felt a significant improvement of dyspnea and hemoptysis alongside with an objective subsiding of poststenotic pneumonia, though spirometric parameters revealed no significant difference. A significant reduction of tumor stenosis (P<0.05) and an improvement of the Karnofsky performance status (P<0.05) were documented 1 and 4 weeks after PDT/HBO. No therapy related complications were observed. CONCLUSION: Although the small number of patients does not allow to draw definitive conclusions, the results suggest that combined PDT/HBO represents a new, safe and technically feasible approach. It enables efficient and rapid reduction of the endoluminal tumor load and helps conditioning the patient for further treatment procedures.

Outer diameter of the vermiform appendix as a sign of acute appendicitis: evaluation at US.

PURPOSE: To evaluate the usefulness and limitations of the outer diameter of the vermiform appendix at cross-sectional ultrasonography to confirm or rule out acute appendicitis. MATERIALS AND METHODS: In a prospective study, outer appendiceal diameters in 240 control subjects and in 278 patients suspected of having acute appendicitis who did (n = 98) or did not (n = 180) have acute appendicitis were measured. RESULTS: Outer appendiceal diameters in the control subjects ranged between 2 and 13 mm, and in 55 (23%) of 240 control subjects, diameters were 6 mm or more. Diameters in the symptomatic patients without acute appendicitis ranged between 2 and 11 mm, and 57 (32%) of 180 patients had diameters of 6 mm or more. Diameters of acutely inflamed appendices ranged between 6 and 30 mm. A diameter of 6 mm or more confirmed acute appendicitis with a sensitivity of 100%; a specificity of 68%; positive and negative predictive values of 63% and 100%, respectively; and an accuracy of 79%. CONCLUSION: The outer appendiceal diameter of 6 mm or more as a sign of acute appendicitis provides high sensitivity but limited specificity. This diagnostic criterion is more useful in excluding acute appendicitis than in confirming it.

Combined photodynamic therapy and hyperbaric oxygenation in carcinoma of the esophagus and the esophago-gastric junction.

OBJECTIVES: The photochemical reaction of photodynamic therapy (PDT) depends on the presence of molecular oxygen. Due to anoxic regions in tumor tissue and vascular shutdown during PDT the efficiency is limited. Therefore, the use of hyperbaric oxygen which increases the oxygen in tumor tissue, as well as the amount of singlet oxygen, may enhance the efficiency of PDT. PATIENTS AND METHODS: After diagnostic work-up, photosensitization was carried out with a hematoporphyrin-derivate 2 mg/kg BW 48 h prior to PDT. The light dose was calculated as 300 J/cm fiber tip. Thirty-one patients were treated by PDT alone and 44 patients received PDT under hyperbaric oxygen at a level of two absolute atmospheric pressure. RESULTS: Improvement regarding stenosis-diameter could be obtained in both treatment arms with no significant difference (P=0.82). The dysphagia-score and tumor-length also decreased in both groups and showed a significant difference in favour of the PDT/HBO-group (P=0. 0064 and P=0.0002, respectively). The median overall survival for the PDT-group was 7 months and for the PDT/HBO-group 12 months (P=0. 0098). CONCLUSION: According to this prospective non-randomized study, combined PDT/HBO represents a new approach in the treatment of esophageal and cardia cancer which appears to have enhanced the efficiency of PDT.

In vivo determination of tumor optical parameters in esophageal carcinoma.

BACKGROUND AND OBJECTIVE: Dose dependence of light cannot be discussed on the basis of dose alone. On a more fundamental scientific level, the propagation of light in tissue depends on optical parameters of treated tumor tissue. In a prospective, nonrandomized study, in vivo optical parameters of esophageal carcinoma were studied. STUDY DESIGN/MATERIALS AND METHODS: Nineteen intraoperative measurements of tumor optical parameters in six patients with esophageal carcinoma were performed. After diagnostic work-up and clinical staging, right-sided, posterolateral thoracotomy, and dissection of the esophagus were carried out. The tumor site was exposed and continuous endoluminal irradiation was started during determination of light penetration at the level of the adventitia of the esophagus. The tumors were located exactly between the endoluminal irradiation source and measurement probe in the thoracic cavity. Measurements were performed on tumors having different diameters to show the relationship between tumor diameter, extinction coefficient, and light penetration depth. RESULTS: The endoluminal incident intensity was 18.5 mW/cm(2). At a tumor diameter of 4, 6, 8, and 9 mm measured intensity of 5.12, 2.28, 0.88 and 0.65 mW/cm(2), an extinction coefficient of 0.321, 0.349, 0.381, and 0.373, as well as penetration depth of 3.21, 2.87, 2.62, and 2. 68 mm, respectively, could be measured. The correlation of tumor optical parameters, tumor diameter, penetration depth, and treatment time were expressed by the relative correction factor for different tumor diameters. CONCLUSION: The knowledge of tumor optical properties seems to be necessary to adapt dosimetry to the individual situation and manage optimal results of PDT in esophageal cancer.

Chemical characterization of sicilian prickly pear (Opuntia ficus indica) and perspectives for the storage of its juice.

In this work, Sicilian cultivars of prickly pear (Opuntia ficus indica) were partially characterized from a chemical point of view, and the possibility of long-term storage of their juice was investigated. The acidity of the prickly pear juice turned out to be very low (0.02%) and the pH very high (6.4-6.5) if compared with values found in other common fruit juices. In the perspective of processing and storage conditions according to Italian law, the acidity has been corrected by adding the proper amount of tartaric and/or phosphoric acid. The sugar content (mainly glucose and fructose) is very high (11-12%), and also L-ascorbic acid is present in considerable amount (31-38 mg/100 g). Among the transition metals, a high content of manganese(II) (1.7-2.9 ppm) and good amounts of iron(III) (0.6-1.2 ppm) and zinc(II) (0.3-0.4 ppm) were found. In particular, such ions appear to be present mainly in the thick skin of the fruit or "trapped" inside the pulp. Pectin methylesterase (PME) seems to be present in very small amount and/or is not highly active. Furthermore, PME activity decreases considerably after the necessary adjustment of the pH and the thermal treatment requested for long-term storage. After approximately 2 months, none of the juices prepared was affected by noticeable sedimentation of the pulp. Finally, different samples of prickly pear juice were sensorially analyzed, employing descriptors such as color, aroma, viscosity, acidity, sweetness, and off-flavors. The results obtained can be considered very satisfactory, and the juice has been widely appreciated when compared with other products commonly available on the market such as pear and peach juices.