Active electrode monitoring

Background: In recent years, the use of minimally invasive surgery (MIS) has expanded to a wide variety of surgical specialties. The increased popularity of the procedure, however, has been accompanied by its share of complications, including trocar lacerations and inadvertent thermal injuries to nontargeted tissues during monopolar electrosurgery. Methods: A survey on electrosurgical thermal injuries and three case studies are presented. The new technology of active electrode monitoring (AEM) is described. Results: AEM eliminates stray currents generated by insulation failure and capacitive coupling. Conclusions: To reduce the incidence of injury by monopolar electrosurgery at laparoscopy, there is a need for advanced technology, such as AEM. In addition, laparoscopic surgeons should be encouraged to study the basic concepts of the biophysics of electrosurgery. Received: 26 June 1997/Accepted: 10 December 1997     

Unrecognized hazards of surgical electrodes passed through metal suction-irrigation devices

Surgical electrodes, passed through metal suction-irrigation devices, pose significant risks for unrecognized visceral burns through capacitively coupled current using monopolar electrosurgery. Plastic cannulas (and reducers) should be avoided with the metal suction-irrigation electrode; an all-metal trocar cannula confers limited safety. With surgeon education and advances in engineering, the potential for unrecognized visceral injury with capacitive coupling can be eliminated.     

Education and engineering solutions for potential problems with laparoscopic monopolar electrosurgery.

The potential problems of monopolar electrosurgery relate to unrecognized energy transfer ("stray current") outside the view of the laparoscope. Mechanisms of stray current and unrecognized tissue injury include: (1) insulation breaks in electrodes; (2) capacitive coupling, or induced currents through the intact insulation of the active electrode to surrounding cannulas or other instruments; and (3) direct coupling (or unintended contact) between the active electrode and other metal instruments or cannulas within the abdomen. Capacitive coupling poses the greatest risk for injury when the outer conductor (trocar cannula or irrigation cannula) is electrically isolated from the abdominal wall by a plastic nonconductor. Capacitive coupling is increased by the coagulation mode (versus cut), open circuit (versus tissue contact with the electrode), 5-mm cannulas (versus 11 mm), and higher voltage generators. The safety of electrosurgery can be enhanced by surgical education regarding the biophysics of radio frequency electrical energy, technical choices in instruments using all-metal cannula systems, and engineering developments with a dynamically monitored system for insulation failure and capacitive coupling.     

Tissue thermal damage caused by bipolar forceps can be reduced with a combination of plastic and metal

Background: We created a new 5-mm bipolar forceps. Thermo-insulating plastic was used for the creation of the jaws, while the metal conductor is buried deep inside the plastic. Methods: A porcine model was used in experimental testing against a standard metallic 5-mm bipolar forceps at three different wattage settings (20, 40, 60 W). Histological sections were evaluated by a pathologist who was blind to the wattage and instrument tested. Results: The new instrument was shown to cause statistically significant reduced thermal damage. In addition, its lateral thermal diffusion is superior to standard bipolar forceps. Conclusions: Thermo-insulating plastics can reduce thermal damage to tissue during electrosurgery. Received: 11 March 1997/Accepted: 19 July 1997     

Intracorporeal colorectal anastomosis following laparoscopic left colon resection

Background: The aim of this study was to assess the impact of an intracorporeal double-stapled colorectal anastomosis upon the outcome of laparoscopic left colon resection. Methods: Fifty-four selected patients underwent elective laparoscopic left colon resection for benign disease. Once resection was completed, a 33-mm suprapubic port allowed insertion of the anvil of a circular stapler into the colon, which was closed by a handsewn purse-string suture using the T-needle technique. The circular stapler was passed transanally to perform a double-stapled anastomosis. Specimens were delivered in a plastic bag via the suprapubic port. Results: There were no deaths. Minor intraoperative and postoperative complications occurred in 3.7% and 9.2% of the patients, respectively. Median operating time was 125 min (range 80–210 min). Complete proximal and distal doughnuts were obtained in all patients and anastomoses were all methylene blue tight. Median hospital stay was 4 (range 3–7) days. Conclusions: Fashioning double-stapled colorectal anastomoses intracorporeally is feasable and safe. Received: 26 March 1996/Accepted: 9 September 1996     

Application of rectal stents for palliation of obstructing rectosigmoid cancer

Background: The rationale of palliative endoscopic treatment is to avoid a colostomy in patients with advanced disease and limited life expectancy. This study was conducted to evaluate the role of endoscopic stent implantation for palliation of obstructing rectal cancer. Methods: Overall, 19 patients (aged 47–87 years) with nonresectable or metastatic rectal cancer were treated by stent insertion after laser recanalization or dilation. Three types of stents, i.e., plastic tubes (n= 8), self-expanding mesh stents (n= 6), and endocoil stents (n= 5), were used to maintain luminal patency. Results: Endoscopic stent implantation was successfully performed in all 19 patients. Long-term luminal patency and satisfactory bowel function were achieved in 16 of 19 patients (84%). After a median follow-up of 6 months, eight of the patients have died and eight are still alive without evidence of recurrent obstruction. Dislocation of the endoprosthesis occurred in two of eight plastic tubes and one of five mesh stents. Recurrent obstruction due to tumor ingrowth was only observed in patients treated with self-expanding mesh stents (n= 2). In spite of reinsertion and laser therapy a colostomy was required in three of 19 patients. There was no evidence of treatment failure in five patients who received endocoil stents. None of the patients experienced serious complications related to the endoscopic procedure. Conclusions: Endoscopic stent implantation seems to be a safe and efficient palliative approach to selected patients with obstructing rectal cancer. Currently, self-expanding coil stents are superior to other devices because of lower risk of dislocation and tumor ingrowth. Received: 10 May 1996/Accepted: 11 November 1996     

Immediate and delayed effects of laparoscopic Nissen fundoplication on pulmonary function

Background: An effort was made to assess the respiratory outcomes of laparoscopic Nissen fundoplication (LNF). Methods: Prospective follow-up of 69 patients undergoing LNF for gastroesophageal reflux disease. Outcomes included pulmonary function testing, 24-h pH recording, esophageal manometry, and symptom assessment. Results: There was an improvement (p < 0.0001) in heartburn and cough scores. There was a significant fall in spirometry (p < 0001), diffusing capacity (p < 0.0001), and respiratory muscle strength (p < 0.0001) 36 h after surgery, which had returned to baseline by 1 month. At 6 months, the patients (n= 16) with impaired preoperative diffusing capacity showed improvement (17.8 ± 3.7 to 19.8 ± 4.6 ml/min/mmHg, p= 0.0245). Conclusion: Patients undergoing LNF have impaired gas exchange before surgery which tends to improve 6 months after surgery. There is an early reversible impairment in respiratory function due to diaphragm dysfunction. Patients with a preoperative 1-s forced expired volume > 1.5, or 50% predicted, are unlikely to develop signficant early respiratory complication. Received: 22 April 1996/Accepted: 9 July 1996     

Management of malignant biliary stricture with self-expanding metallic stent

Background: Self-expanding metallic mesh stents are designed to remain patent longer than polyethylene (PE) stents, which generally clog in 3 to 4 months. Though more expensive, metal stents may therefore be a better choice for malignant strictures. Methods: From January 1991 to October 1995, we performed ERCP in 212 patients with malignant or benign strictures, and 34 ultimately had insertion of a metallic stent. These stents were placed by the percutaneous transhepatic route in 17 patients and endoscopically in 17. Results: Metallic stent insertion was successful in each case and relieved the preoperative jaundice and cholangitis. There were no procedure-related deaths; complications were pancreatitis (one) and hemorrhage (one). Overall stent patency was 6.2 months. Three of 34 stents occluded due to tumor ingrowth at 3, 4.5, and 8 months and were treated by placing a new PE stent through the blocked metal stent. The remaining 31 stents remained patent until patient death (n= 15, mean survival = 4.9 months) or are still open (n= 16, mean patency = 12.2 months). Conclusions: Self-expanding metal stents provide effective palliation of malignant biliary strictures and should be considered an alternative to open surgery. Metal stents remain patent much longer than PE stents and usually a single session of metal stenting can palliate biliary obstruction for life. Received: 20 March 1996/Accepted: 9 May 1996     

A murine model of laparoscopic-assisted intervention

Background: In order to better investigate the effects of laparoscopic surgery, it is necessary to establish reliable, reproducible, and economical animal models of laparoscopic intervention. Here we describe a mouse model of laparoscopic-assisted colon resection. Methods: After successful induction of anesthesia the mouse is placed in Trendelenburg position and the peritoneal cavity is insufflated with carbon dioxide gas through an angiocatheter placed in the right upper quadrant. A 4-mm rigid scope with camera attachment is then inserted through a midline port created just caudal to the xiphoid. A second port is then created in the right lower quadrant to allow introduction of laparoscopic forceps into the peritoneal cavity. The cecum, which extends 1.5 cm beyond the ileocecal valve, is grasped with forceps and exteriorized through the operative port. Extracorporeally, the cecum is ligated and resected before the cecal stump is returned to the peritoneal cavity. The abdominal wall defects are then stapled closed. Results: This simple model can be mastered by individuals with very limited surgical experience. This laparoscopic model has been used successfully in our laboratory in a number of experiments with an intraoperative complication rate of 3.2% (3/94), which was similar to the open surgery group rate of 2.1% (2/95, p= 0.99 by chi square). We observed no postoperative leaks in either group. The only postoperative death occurred in the open resection group due to dehiscence of the laparotomy wound. Conclusions: We propose that this model may be useful for comparing the effects of open to laparoscopic surgery. Received: 19 June 1996/Accepted: 2 November 1996     

Port-site metastases

Background: Port-site metastases after laparoscopic procedures in patients with digestive malignancies have evoked concern. The pathogenesis of port-site metastases remains unclear. Two experiments in rats were performed to determine the impact of both tissue trauma and leakage of CO₂ along trocars (chimney effect) in the development of port-site metastases. Methods: Experiment I: Ten WAG rats had four 5-mm incisions in all abdominal quadrants. The incisions on the right side were crushed to induce tissue trauma. After inserting 5-mm trocars in all incisions, a pneumoperitoneum was created, and CC-531 tumor cells were injected intraperitoneally. CO₂ was insufflated for 20 min. Experiment II: Ten WAG rats had 5-mm incisions in the left and right abdominal upper quadrant. A 5-mm trocar was inserted in the incision in the left upper quadrant, and a 2-mm trocar was inserted in the incision in the right upper quadrant. After insufflating the abdomen, CC-531 tumor cells were injected intraperitoneally. Total leakage of CO₂ along the trocar in the right quadrant was 10 liters. After 4 weeks, in both experiments, the tumor deposits at the trocar sites were assessed. Statistical analysis was performed by the Wilcoxon matched-pairs test. Results: Experiment I: The median weight of tumor deposits at the trocar sites without induced tissue trauma was 22 mg. At the traumatic port sites, median weight of tumor deposits was 316 mg (p= 0.007). Experiment II: The median weight of tumor deposits at the leaking trocar sites was 478 mg and at the control sites 153 mg (p= 0.009). Conclusion: Tissue trauma at trocar sites and leakage of CO₂ along a trocar appear to promote implantation and growth of tumor cells at port sites. Received: 15 May 1997/Accepted: 3 March 1998     

Endoscopic photodynamic therapy for obstructing esophageal cancer: 77 cases over a 2-year period

rid="id="<e5>Correspondence to:</e5> J. D. Luketich, 200 Lothrop Street, C-800, Presbyterian Hospital, Pittsburgh, PA 15213, USA Background: Photodynamic therapy (PDT) is an alternative treatment option for the palliation of obstructive esophageal cancer. We report our experience with PDT for patients presenting with inoperable, obstructing, or bleeding esophageal cancer. Methods: Seventy-seven patients with inoperable, obstructing esophageal cancer were treated with PDT from November 1996 to July 1998. Photofrin (1.5–2.0 mg/kg) was administered, followed by endoscopic light treatment (630 nm red dye laser) at 48 h. Dysphagia score (1 for no dysphagia to 5 for complete obstruction), dysphagia-free interval, and patient survival were assessed. Results: Seventy-seven patients underwent 125 PDT courses. The mean dysphagia score at 4 weeks after PDT in 90.8% of the patients improved from 3.2 ± 0.7 to 1.9 ± 0.8 (p < 0.05). PDT adequately controlled bleeding in all six patients who had bleeding. The most common complications after the 125 PDT courses were esophageal stricture (4.8%), Candida esophagitis (3.2%), symptomatic pleural effusion (3.2%), and sunburn (10.0%). Twenty-nine patients (38%) required more than one PDT course, and seven patients required placement of an expandable metal stent for recurrent dysphagia. The mean dysphagia-free interval was 80.3 ± 58.2 days. The median survival was 5.9 months. Conclusions: Photodynamic therapy is a safe and effective treatment for the palliation of obstructing and bleeding esophagus cancer. Received: 8 May 1999/Accepted: 24 September 1999/Online publication: 15 May 2000     

Does the ultrasonically activated scalpel release viable airborne cancer cells?

Background: Viable cancer cells may implant at distant sites and cause tumor recurrence. One possible mechanism is the inadvertent exfoliation of viable tumor cells during dissection. The ultrasonically activated scalpel (UAS) uses ultrasonic energy to disrupt tissues by cavitation and produces a dense cloud of cellular debris that may contain viable cells. This study aimed to investigate the viability of airborne cells released during cancer dissection using the UAS and electrosurgery. Methods: Flank tumors (n= 8) measuring 1 cm³ were induced in male WAG rats by subcutaneous injection of 2 × 10⁶ CC531s colon cancer cells. Dissection was performed in cutting mode using the maximum power output of the respective devices. Electrosurgery was performed using a standard monopolar electrosurgical unit and a needle probe, and ultrasonic dissection was performed with the Harmonic Scalpel™ utilising the open surgical handset and the hooked spatula tip. The smoke plume was aspirated by a vacuum pump and bubbled under Hank's balanced salt solution to trap particulate matter. The viability of the cellular material was blindly assessed with the trypan blue test and by in vitro culture. The morphology of the cellular debris was studied by examination of cytospin preparations. Results: Large quantities of cellular debris was trapped in the plume from both devices. However, no viable cells were isolated, nor did in vitro cell growth occur with either device. Examination of the debris from the UAS demonstrated a characteristic mixture of amorphous forms and very few morphologically intact cells. The cauterized tumor produced charred cells and tissue fragments. Conclusions: In conclusion, this study demonstrates that viable airborne cancer cells are not released after tumor ablation with the UAS or electrosurgery. Received: 6 June 1997/Accepted: 20 November 1997     

Does laparoscopy increase bacteremia and endotoxemia in a peritonitis model?

Background: Laparoscopy is increasingly used in patients with intraabdominal bacterial infection although pneumoperitoneum may increase bacteremia by elevated intraabdominal pressure. Methods: The influence of laparotomy and laparoscopy on bacteremia, endotoxemia, and postoperative abscess formation was investigated in a rat model. Rats received intraperitoneally a standardized fecal inoculum and underwent laparotomy (n= 20), or laparoscopy (n= 20), or no further manipulation in the control group (n= 20). Results: Bacteremia and endotoxemia were higher after laparotomy and laparoscopy compared to the control group (p= 0.01) 1 h after intervention. One hour after intervention, aerobic and anaerobic bacterial species were detected in the laparotomy group while only anaerobic bacteria were found in the other two groups. Although bacteremia and endotoxemia did not differ among the three groups after 1 week, the mean number of intraperitoneal abscesses was significantly higher (p < 0.05) after laparotomy (n= 10) compared with laparoscopy (n= 6) and control group (n= 5). Conclusion: Laparoscopy does not increase bacteremia and intraperitoneal abscess formation compared to laparotomy in an animal model of peritonitis. Received: 28 May 1996/Accepted: 25 July 1996     

The effect of immune enhancement and suppression on the development of laparoscopic port site metastasesrid=""id=""Presented at the 6th World Congress of Endoscopic Surgery, Rome, Italy, June 1998

Background: Recent clinical case reports and experimental studies have suggested that laparoscopic cancer surgery is associated with an increased risk of tumor spread to abdominal wall wounds. While the etiology of this problem was initially believed to be related to mechanical contamination of wounds, it is now recognized that there are other contributory factors, including disturbed immune function within the peritoneal cavity. To investigate this question further, we evaluated the effect of immune modulation within an established laparoscopic cancer model. Methods: Eighteen immune-competent syngeneic rats underwent modulation of their immune system, followed 18 h later by laparoscopy with the introduction of a suspension of adenocarcinoma cells into the peritoneal cavity. Rats were randomly allocated to receive either systemic cyclosporin (immune suppresser), intraperitoneal endotoxin (immune enhancer), or no agent (controls). Seven days later, all rats were killed and their peritoneal cavity was inspected for tumor implantation and port site metastases. Results: Cyclosporin did not influence the study outcome, but tumor growth (p= 0.008) and port site metastases (p < 0.0001) were less common following the administration of intraperitoneal endotoxin. Conclusion: The results of this study suggest that the immune system plays a role in the genesis of port site metastases. A preventive role for endotoxin in patients undergoing laparoscopic cancer surgery, however, remains speculative. Received: 22 July 1998/Accepted: 23 June 1999     

Laparoscopic cecal ligation and puncture in the rat

Background: We describe a technique of laparoscopic cecal ligation and puncture (CLP) in the rat analogous to open CLP which may facilitate the study of minimally invasive surgery (MIS) and peritonitis. Methods: Forty-four rats were randomized to either laparoscopic or open CLP and their 3-day mortality was recorded. Autopsies were performed for peritoneal fluid cultures, measurement of the length of ligated cecum, and scoring of the degree of cecal necrosis. Results: Laparoscopic CLP required slightly longer operating times compared to open CLP (average 15.6 vs 13.1 min, p= 0.002). Three-day postoperative mortality was 36.4% and 22.7% for open and laparoscopic CLP, respectively (p= NS). There were no differences in the length of ligated cecum or the cecal necrosis score between the open and laparoscopic CLP groups. Conclusion: Laparoscopic CLP is feasible and produces a fecal peritonitis with similar characteristics to those of traditional open CLP. Received: 3 July 1996/Accepted: 7 January 1997     

Laparoscopic ventral hernia repair

Introduction: Effective surgical therapy for ventral and incisional hernias is problematic. Recurrence rates following primary repair range as high as 25–49%, and breakdown following conventional treatment of recurrent hernias can exceed 50%. As an alternative, laparoscopic techniques offer the potential benefits of decreased pain and a shorter hospital stay. This study evaluates the efficacy of the laparoscopic approach for ventral herniorrhaphy. Methods: A retrospective review was performed for 100 consecutive patients with ventral hernias who underwent laparoscopic repair at our institutions between November 1995 and May 1998. All patients who presented during this period and were candidates for a mesh hernia repair were treated via an endoscopic approach. Results: One hundred patients underwent a laparoscopic ventral hernia repair. There were 48 men and 52 women. The patients were typically obese, with a mean body mass index (BMI) of 31 kg/m². Each had undergone an average of 2.5 (range; 0–8) previous laparotomies. Forty-nine repairs were performed for recurrent hernias. An average of two patients (range; 1–7) had previously failed open herniorhaphies; in 20 cases, intraabdominal polypropylene mesh was present. There were no conversions to open operation. The mean size of the defects was large at 87 cm² (range; 1–480). In all cases, the mesh (average, 287 cm²) was secured with transabdominal sutures and metal tacks or staples. Operative time and estimated blood loss averaged 88 min (range; 18–270) and 30 cc (range; 10–150). Length of stay averaged 1.6 days (range; 0–4). There were 12 minor and (two) major complications: cellulitis of the trocar site (two), seroma lasting >4 weeks (three), postoperative ileus (two), suture site pain > 2 weeks (two), urinary retention (one), respiratory distress (one), serosal bowel injury (one), and skin breakdown (one) and bowel injury (one). Both of the latter complications required mesh removal. With an average follow-up of 22.5 months (range; 7–37), there have been (three) recurrences. Conclusion: The laparoscopic approach to the repair of both primary and recurrent ventral henias offers a low conversion rate, a short hospital stay, and few complications. At 23 months of follow-up, the recurrence rate has been 3%. Laparoscopic repair should be considered a viable option for any ventral hernia. Received: 11 February 1999/Accepted: 15 March 2000/Online publication: 28 April 2000     

Multicentric experience of the Belgian Group for Endoscopic Surgery (BGES) with endoscopic adrenalectomy

Background: Adrenalectomy is not a frequent operation. Therefore the newly developed laparoscopic approach is sporadically performed by surgeons dealing with endocrine disorders. Methods: Some 54 videoendoscopic adrenalectomies performed on 52 patients by five surgical teams between October 1993 and December 1996 were prospectively evaluated. Results: Indications for endoscopic adrenalectomy were pheochromocytoma (n= 17), primary hyperaldosteronism (n= 15), Cushing's adenoma or disease (n= 7), nonsecreting adenoma (n= 7), single metastasis from adenocarcinoma (n= 2), adenoma with dehydroepiandrostenedione (DHEAS) hypersecretion (n= 3), and ACTH-secreting metastases from a thymoma (n= 1). Of the 54 adrenalectomies performed, 31 were of the left gland, 19 of the right and two bilateral. Laparoscopic adrenalectomy was successful in 50 patients (96%). Median tumor size was 4 cm (range 1.5–12), median operation duration was 80 min (range 59–360), and median postoperative stay was 4 days (range 2–13). One patient required blood transfusion. Conclusions: Endoscopic adrenalectomy can safely be performed—even sporadically—by surgeons well versed in adrenalectomy techniques for endocrine disorders and trained in endoscopic surgery. Received: 25 March 1997/Accepted: 16 May 1997     

Geometry and reproducibility in 360° fundoplication

Background: In this study, we set out to precisely define two symmetrical points—a on the anterior fundic wall and b on the posterior fundic wall. These points, when advanced around a 60-Fr bougie-filled esophagus, will meet on the right side, to the right of the anterior vagus nerve, to create a reliable, reproducible, loose (i.e., or ``floppy') 360° fundoplication (FP). Methods: For the terms of this study, circumference =c; diameter =d; c/d=π; π= 3.14; and d(cm) = Fr/30. Using a flexible plastic ruler, we measured, in cadavers (n= 5) and intraoperatively (n= 16), esophageal c at the gastroesophageal junction (GEJ) with a 60-Fr bougie in place; d was calculated from c. Results: The smallest measured value for c was 7.5 cm (d= 2.39 cm); the largest value for c was 10.0 cm (d= 3.18 cm). The mean value was 8.35 cm (d= 2.66 cm). Points a and b are established by measuring laterally from a point where the greater curve meets the GEJ in the bougie-filled esophagus. Point a is 6.0 cm laterally and 6.0 cm below the short gastric vessels on the anterior fundus; point b is 6.0 cm laterally in a symmetrical position on the posterior fundus. Connecting these three points as a line defines the inner c of the completed FP and measures 12.0 cm. This gives an internal d of 3.82 cm for the FP. This is >1 cm larger than d for the mean measured external esophageal c of 8.35 cm where d= 2.66 cm. This technique creates a correctly oriented, symmetrical, ``floppy,' true fundoplication. It avoids wrapping or twisting the fundus around the GEJ. The technique is easily taught and reproducible. Conclusions: Two points, measured a horizontal distance of 6.0 cm from the GEJ, symmetrically placed on the anterior (point a) and posterior (point b) fundus can be brought anterior (a) and posterior (b) to the esophagus and sutured to the right of the anterior vagus nerve to reliably and reproducibly create a ``floppy' 360° fundoplication. Received: 20 April 1999/Accepted: 15 February 2000/Online publication: 15 May 2000     

Bone Metabolism in Endurance Trained Athletes: A Comparison to Population-Based Controls Based on DXA, SXA, Quantitative Ultrasound, and Biochemical Markers

In general, physical exercise appears to have favorable effects on the skeleton. However, a few recent reports have described negative effects, including reduced bone density (BMD) and high bone turnover in runners. The aim of our study was to compare endurance runners to controls with respect to BMD at different sites and ultrasound transmission through the peripheral skeleton, and to use PTH, total serum calcium, and biochemical markers of bone metabolism as a complement in evaluating the effects of endurance running on bone. Thirty runners (mean age 32 years, range 19–54 years) participated in the study. Their main form of training consisted of endurance running at moderate intensity for about 7 hours (range 2–12 hours) per week, and they had been active in their sport for about 12 years (range 1–21 years). For a comparison, 30 age- and sex-matched population based controls were investigated. BMD values, measured by dual energy X-ray absorptiometry (DXA), were higher in runners than in controls for the total body (3.6%; P= 0.03), legs (9.6%; P= 0.001), femoral neck (10.0%; P= 0.01), trochanter (9.9%; P= 0.01), and Wards triangle (11.8%; P= 0.02), but not in the lumbar spine or in the forearm measured by single energy X-ray absorptiometry (SXA). The quantitative ultrasound measurement of the calcaneus also revealed higher values in runners than in controls for both broadband ultrasound attenuation (9.2%; P= 0.002) and speed of sound (3.1%; P= 0.0001). At all sites, BMD was related to ultrasound measurements in controls, but no such relationship was evident in runners. Concentrations of parathyroid hormone (PTH) were lower (23.2%; P= 0.02) in runners than in controls, whereas total serum calcium concentrations were slightly higher (3.0%; P= 0.003). The levels of PICP (bone formation) and ICTP (bone resorption) in serum were lower (18.0%; P= 0.03 and 22.2%; P= 0.004, respectively) in runners than in controls, but no differences were seen for osteocalcin or bone specific alkaline phosphatase (b-ALP). In conclusion, BMD at the focus of strain for running, that is, the legs, is higher in endurance runners when compared to matched controls. Low bone turnover in runners, indicated by lower levels of PTH and biochemical markers of bone metabolism, point to an influence of endurance running at the cellular level. Received: 25 July 1996 / Accepted: 24 March 1997     

Influence of Body Mass Index on the Age-related Slope of Total and Regional Bone Mineral Content

The influence of body mass index (BMI) on T scores for total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) was studied in 186 healthy women: 100 postmenopausal, 35 perimenopausal, and 51 premenopausal. The three groups were divided by BMI >25 kg/m² and BMI <25 kg/m² and the postmenopausal women were further subdivided by years since menopause (YSM): <10, 10–20, and >20. Tartrate-resistant acid phosphatase (TRAP) concentration was higher in perimenopausal and postmenopausal women with BMI <25 kg/m² (P < 0.001). T scores for TBBMC and for axial or peripheral RBMC differed (P < 0.05 in all) between women with BMI >25 kg/m² and BMI <25 kg/m². The rate of perimenopausal and postmenopausal age-related slope of BMC, as reflected in all measurements, differed with BMI. In the overall group of women, the T score for TBBMC correlated significantly with BMI (r = 0.46, P < 0.0001); this correlation increased when adjusted for age (r = 0.62, P < 0.0001). BMI correlated with TRAP only in postmenopausal women (r = 0.57, P < 0.0001). Yearly TBBMC decline was twice as high in postmenopausal women with BMI <25 kg/m² (P= 0.0004) than in those with BMI >25 kg/m²; the decline of trunk RBMC was more significant (P < 0.0001). These findings confirm the influence of BMI and gonadal status on bone mass. Received 20 February 1996 / Accepted 31 December 1996