Efficacy of conventional monitoring techniques in free tissue transfer: an 11-year experience in 750 consecutive cases

Conventional free flap monitoring techniques (clinical observation, hand-held Doppler ultrasonography, surface temperature probes, and pinprick testing) are proven methods for monitoring free flaps with an external component. Buried free flaps lack an external component; thus, conventional monitoring is limited to hand-held Doppler ultrasonography. Free flap success is enhanced by the rapid identification and salvage of failing flaps. The purpose of this study was to compare the salvage rate and final outcomes of buried versus nonburied flaps monitored by conventional techniques. This study is a retrospective review of 750 free flaps performed between 1986 and 1997 for reconstruction of oncologic surgical defects. There were 673 nonburied flaps and 77 buried flaps. All flaps were monitored by using conventional techniques. Both buried and nonburied flaps were used for head and neck and extremity reconstruction. Only nonburied flaps were used for trunk and breast reconstruction. Buried flap donor sites included jejunum (n = 50), fibula (n = 16), forearm (n = 8), rectus abdominis (n = 2), and temporalis fascia (n = 1). Overall flap loss for 750 free flaps was 2.3 percent. Of the 77 buried flaps, 5 flaps were lost, yielding a loss rate of 6.5 percent. The loss rate for nonburied flaps (1.8 percent) was significantly lower than for buried flaps (p = 0.02, Fisher's exact test). Fifty-seven (8.5 percent) of the nonburied flaps were reexplored for either change in monitoring status or a wound complication. Reexploration occurred between 2 and 400 hours postoperatively (mean, 95 hours). All 44 of the salvaged flaps were nonburied; these were usually reexplored early (<48 hours) for a change in the monitoring status. Flap compromise in buried flaps usually presented late (>7 days) as a wound complication (infection, fistula). None of five buried flaps were salvageable at the time of reexploration. The overall salvage rate of nonburied flaps (77 percent) was significantly higher than that of buried flaps (0 percent, p<0.001, chi-square test). Conventional monitoring of nonburied free flaps has been highly effective in this series. These techniques have contributed to rapid identification of failing flaps and subsequent salvage in most cases. As such, conventional monitoring has led to an overall free flap success rate commensurate with current standards. In contrast, conventional monitoring of buried free flaps has not been reliable. Failing buried flaps were identified late and found to be unsalvageable at reexploration. Thus, the overall free flap success rate was significantly lower for buried free flaps. To enhance earlier identification of flap compromise in buried free flaps, alternative monitoring techniques such as implantable Doppler probes or exteriorization of flap segments are recommended.     

Monitoring flap for buried free tissue transfer: its importance and reliability

To improve the success rate of microsurgical flap transfers into a buried area, it is important to monitor the circulation of the flap during the early stage. A monitoring flap includes such advantages as simplicity, reliability, noninvasiveness, and the ability to continuously monitor the vascular status of various buried flaps. This article describes experiences related to the importance and reliability of a monitoring flap. A total of 109 flaps in 99 patients were treated with buried free flaps, including a monitoring flap, between 1990 and 1999. Forty-nine patients received a tubed free radial forearm flap with a skin-monitoring flap, and six received a free jejunal flap with a jejunal segment monitoring flap for the reconstruction of the esophagus. Vascularized fibular grafts with a skin monitoring flap or peroneus longus muscle monitoring flap were used for reconstructing the mandible in six patients and for treating osteonecrosis of the femoral head in 48 flaps in 38 patients. Monitoring flap abnormalities were indicated in 14 flaps; therefore, immediate revisions were performed on the pedicle of the monitoring flap and microanastomosis site. Among these 14 flaps, nine showed true thrombosis and five showed false-positive thrombosis. Among the nine flaps that showed true thrombosis, five were salvaged and four were finally lost. The false-positive thrombosis in the five flaps was attributed to torsion or tension of the perforator of the monitoring flap in three flaps, an unclear determination in one flap because the monitoring flap size was too small, and damage to the perforator in the last flap. The total thrombosis rate was 8.3 percent (nine of 109), and the failure rate of the free tissue transfer was 3.7 percent (four of 109). The overall sensitivity of the monitoring flap was 100 percent, the predictive value of a positive test was 64 percent (nine of 14), and false-positive results occurred in 36 percent (five of 14). The salvage rate was 55.6 percent. To improve the reliability of a monitoring flap, it is recommended that the size of the flap be larger than 1 x 2 cm to assess the arterial status, and that a perforator with the appropriate caliber be selected. When a monitoring flap is fixed to a previous incision line or a newly created wound, any torsion or tension of the perforator should be avoided. In conclusion, the current results suggest that a monitoring flap is a simple, extremely useful, and reliable method for assessing the vascular status of a buried free flap.     

Laser Doppler blood flow measurements of common cutaneous donor sites for reconstructive surgery

The purpose of this study was to evaluate cutaneous blood flow in regions commonly used as donor sites in reconstructive surgery in order to better establish normal flow ranges. Flow was measured with the TSI Laserflo BPM 403 in 27 healthy volunteers and compared to the flow in uncomplicated postoperative autologous tissue transplants. The forehead produced the highest flow, with an average value of 6.50 +/- 0.31 (mean +/- SE), and the dorsalis pedis had the lowest flow, with an average value of 0.60 +/- 0.04. Gender differences were noted in the latissimus dorsi, pectoralis major, and rectus abdominis areas. There were no significant differences between smokers and nonsmokers, hand dominance, musculocutaneous and fasciocutaneous tissues, or supine and sitting body positions. Flow levels in volunteers were similar to those in postoperative surviving autologous tissue transplants. The site-specific flow and flow changes over long time periods (hours) have helped clinical monitoring of 77 patients in the last 24 months. In every case identified by the flowmeter as decreased perfusion, a definite etiology for low reduction was documented. Complications occurred in 12 patients, and the rate of salvaging compromised tissue has increased from 50 percent using temperature monitoring and clinical observation to 83 percent with the computerized laser Doppler flowmeter.     

The diagnosis of osteomyelitis in patients with pressure sores

A prospective blind trial was undertaken to assess the usefulness of commonly used tests to diagnose osteomyelitis underlying pressure sores. Sixty-one pressure sores were studied, with a histopathologic diagnosis from the ostectomy specimen being available in 52. White cell count, erythrocyte sedimentation rate, plain pelvic x-ray, technetium-99m bone scan, computerized tomography, and Jamshidi needle bone biopsy were studied. The most useful individual test was a needle bone biopsy, with a sensitivity of 73 percent and a specificity of 96 percent. Technetium-99m bone scans and computerized tomography are not indicated in the diagnosis of osteomyelitis associated with pressure sores. Plain pelvic x-ray, white cell count, and erythrocyte sedimentation rate, with a diagnosis of osteomyelitis if any test is positive, is the most sensitive (89 percent), specific (88 percent), noninvasive workup. Jamshidi needle biopsy may be useful where these tests are negative and a clinical suspicion of osteomyelitis remains. Extent of surgical debridement and antibiotic therapy can then be rationally decided on the basis of this information.     

Improved salvage of complicated microvascular transplants monitored with quantitative fluorometry.

Quantitative fluorometry has been used to monitor circulation in transplanted toes and cutaneous flaps in our unit since 1982. Analysis of 177 uncomplicated transplants monitored by quantitative fluorometry shows that this technique has low false indication rates for arterial occlusion (0.6 percent of patients) and venous occlusion (6.2 percent of patients). None of these patients was reexplored because of a false monitor reading, and except for single abnormal sequences, monitoring appropriately indicated intact circulation throughout the postoperative period. Quantitative fluorometry has correctly indicated vascular complications in 21 (91.3 percent) of 23 transplants over an 8-year period. The salvage rate (85.7 percent) of the fluorescein-monitored reexplored transplants was significantly higher than the salvage rates of similar reexplored transplants not monitored with fluorescein and of reexplored muscle flaps (which cannot be monitored with the fluorometer used at this unit). These clinical data indicate that quantitative fluorometry is a valid and useful postoperative monitor for transplanted toes and cutaneous flaps.     

Synthesis, turnover and compartment analysis of the free fatty acids in the placenta of rats.

The in vivo tracer method and in vitro acetate incorporation experiments were used to investigate the metabolism of placental free fatty acids. Analysis of data revealed that free fatty acids pass into the fetus from maternal plasma through a small placental compartment, which accounts for only 5 percent of all of the placental free fatty acids. The turnover time of this compartment is 0.57 min. The rate of placental fatty acid synthesis evaluated by both methods is very small and amounts to 0.003 mumols fatty acids/min/all placentas of one litter.     

Influence of recipient vessels on free tissue transplantation of the extremities

A retrospective analysis of the records of 107 free flap transplants in 94 patients operated on between May of 1992 and September of 1997 at the Center for Microsurgery of Extremities, Nopparatrajathanee Hospital, was conducted to study the risk factors leading to free flap failure. These factors were periods of operation to reflect the experience of the surgeon, locations of the defects, anastomotic techniques, and the use of vein grafts. Chi-square, Fisher's exact test, and multiple logistic regression analysis were used to determine the significance of the data. The overall vascular complication rate was 28 percent (30 of 107 transplants) and the re-exploration rate was 13 percent (14 of 107 transplants), the flap salvage rate was 50 percent (7 of 14 flaps), whereas the overall failure rate was 15 percent (16 of 107 transplants). The significant factors that caused free flap failure were the experience of the surgeon and the use of vein grafts. The most important experience was in the choice and preparation of the recipient vessel. When the surgeon gained more experience in the past 2 years (from October of 1995 to September of 1997), the success rate improved significantly. Moreover, the use of vein grafts no longer affected the outcome. Therefore, in this investigation the most important factor that improved the outcome of free tissue transplantation in the extremities was the experience of the surgeon in choosing and preparing the recipient vessels.     

Microvascular reconstruction of the hypopharynx: defect classification,treatment algorithm,and functional outcome based on 165 consecutive cases

The objectives of this study were three-fold: to develop a scheme for classification of hypopharyngeal defects, to establish a reconstructive algorithm based on this system, and to assess the functional outcome of such reconstruction. This study is a retrospective review of a 14-year experience with 165 consecutive microvascular reconstructions of the hypopharynx in 160 patients. The average patient age was 59 years (95 percent CI, 37 to 81). Thirty-four patients were operated on for recurrent disease; 71 had preoperative radiotherapy. Partial defects were reconstructed with radial forearm flaps (n = 52); circumferential defects were reconstructed with jejunum (n = 90); and extensive, noncircumferential longitudinal defects were reconstructed with rectus abdominis flaps (n = 23). The overall free flap success rate was 98 percent. Six flaps required reexploration, two of which were salvaged. The incidence of fistula was 7 percent and stricture, 4 percent. Preoperative radiotherapy was significantly associated with risk of recipient site complications (OR, 2.3; 95 percent CI, 1.0 to 5.0). Follow-up data were available on 95 percent of patients: 53 percent were able to tolerate an unrestricted diet, 23 percent a soft diet, 12 percent liquids only, and 12 percent were limited to tube feedings. The treatment algorithm for microvascular hypopharyngeal reconstruction is based on the type of defect with partial defects with radial forearm flaps, circumferential defects reconstructed with free jejunal flaps, and extensive, multilevel defects reconstructed with rectus abdominis myocutaneous flaps. Microvascular reconstruction of pharyngeal defects is highly successful with few postoperative complications. With appropriate flap selection, functional outcome can be optimized.     

The relationship between breast cancer and augmentation mammaplasty: an epidemiologic study

Surgical implantation of breast prostheses for cosmetic purposes has become increasingly popular, and by 1981, it was estimated that three-quarters of a million women had had such an operation. The long-term potential risks, particularly of breast cancer, of such procedures have not been properly investigated. To evaluate the potential breast cancer risk, we have conducted a retrospective cohort study of 3111 women followed through various public and medical records for a total of 18,476 person-years, with a median of 6.2 years per person. The cases of breast cancer were detected by means of a computerized match with the Los Angeles County Cancer Surveillance Program, a population-based cancer registry. Overall, 15.7 breast cancer cases were expected and 9 were observed, a nonsignificant deficit [standardized incidence ratio (SIR) = 57 percent, 95 percent confidence limits: 26 percent, 109 percent]. The cancers were generally diagnosed at an early stage. Among the 573 women aged 40 or older at implantation, 7.1 cases were expected and 8 were observed (SIR = 113 percent). In women whose implants were performed before the age of 40, only 1 case was observed whereas 8.6 cases were expected (SIR = 12 percent, 95 percent confidence limits: 0.3 percent, 65 percent), a significant difference. These data do not support an increased risk of breast cancer following augmentation mammaplasty. The low breast cancer rate in women having augmentation mammaplasty at a young age that many such women may have a reduced amount of breast tissue, but data on this are unavailable.     

Computerized method for analyzing maximum and partial expiratory flow-volume curves.

Computerized instrumentation and software have been developed to obtain maximum expiratory flow-volume (MEFV) and partial expiratory flow-volume (PEFV) curves. The computerized system calculates and prints out the flow at 25% and 40% of control vital capacity (VC), the expiratory volume, peak expiratory flow rate and expiratory volume at one second (FEV1) divided by VC, the latter expressed as a percent. The flow-volume curves can be displayed on an oscilloscope or plotter and stored on magnetic tape. A pilot study was completed to demonstrate the reliability and validity of the data obtained.     

Factors influencing genetic counseling attendance rate: a geographically based study

A study of factors influencing genetic counseling attendance rate has been conducted in the Bouches-du-Rh?ne area, in the south of France. In this area, a birth defects monitoring system (Eurocat n. 22) annually covers 23,000 births. All the genetic services are delivered by only one genetic center located in Marseilles, and the data collected are computerized. The comparison of these two data bases gives an opportunity to estimate the rate of genetic counseling attendance after the occurrence of an affected stillbirth or live birth. Among the parents of 358 infants born in 1983-84 in this area with a pathology requiring genetic counseling, 226 (63 per cent) attended the Genetic Center within the first year after birth. The rate of attendance is statistically higher (p less than 0.01) for the parents who had a stillbirth (78 per cent) than for those who had a live birth (57 per cent). It is also higher (p less than 0.01) for the Marseilles maternities group (68 per cent) than for the group outside Marseilles (50 per cent). The referral delays are also analyzed according to malformation etiology and to viability of the child by the eighth day of life. Besides evaluating a particular genetic center's effectiveness in diffusing information to the public concerned, this work shows that couples' request is strongly dependent on a psychological need.     

Intramucosal PCO2 measurement as a new monitoring method of free jejunal transfer following pharyngo-laryngo-esophagectomy

The choices for practical monitoring of free jejunal transfer have been quite limited because of its own characteristics, such as buried form, lack of skin surface, and the structure of a hollow viscous tract. Physiologically, it is known that tissue hypoxia caused by compromised perfusion leads to an increase of partial pressure of carbon dioxide (PCO2). Because of its physiological properties, the diffusion of carbon dioxide is always equilibrated between the mucosa of a hollow viscous organ and its lumen. The intramucosal PCO2 (PiCO2) of the gastrointestinal tract can therefore be determined indirectly from the intraluminal PCO2, which is measured with the aid of the tonometer catheter. To develop an optimal monitoring method for free jejunal transfer, the authors proposed the application of PiCO2 measurement by a modified use of a tonometer catheter. Since May of 1999, the authors performed postoperative PiCO2 monitoring on 20 cases of reconstructed pharyngoesophageal tracts in 18 patients who underwent radical tumor resection and one-stage reconstruction at the Shizuoka Red Cross Hospital. All 20 cases were safely monitored by PiCO2 measurement without any complications associated with the use of the tonometer catheter. In the 17 cases that succeeded uneventfully, the mean values of PiCO2 were kept lower than 40 mmHg throughout the monitoring period. On the other hand, the other three cases (15 percent) needed reexploration due to development of vascular complications, which was alerted by an abrupt increase of PiCO2 in each case (229, 130, and 99.6 mmHg). Two of the patients were fortunately successfully treated by immediate reexploration, leading to a 95 percent overall success rate. No false-negative or false-positive cases were observed. The authors' experience suggests that PiCO2 measurement using a tonometer catheter can provide the surgeon with reliable information for evaluating the perfusion and viability of a free jejunal transfer. Simplified manipulation and the objectivity of the numerical data allow stable measurement of PiCO2 and prompt judgment of the adequacy of the perfusion, which could minimize the burden and anxiety of the surgeon, particularly in the early postoperative period.     

The deep inferior epigastric perforator flap for breast reconstruction in overweight and obese patients

The authors retrospectively reviewed the computerized records of 71 women undergoing 80 deep inferior epigastric perforator (DIEP) flap reconstructions after mastectomy over a 1-year period. There were 33 normal, 26 overweight, and 12 obese patients. No statistically significant difference in flap complications was found between groups. Overall fat necrosis rates were 11.4 percent for the normal-weight patients, 6.7 percent for the overweight patients, and 6.7 percent for the obese patients. Postoperative hospital time was similar for all groups. The occurrence of abdominal wall fascial laxity was uncommon and similar for all groups. Large (>900 g) reconstructions were completed without prohibitive complications in the reconstruction flap. The DIEP flap represents a significant advance in autologous breast tissue reconstruction. Although concerns regarding fat necrosis rates in DIEP flaps have been voiced, the authors did not see an increasing rate of fat necrosis in their overweight and obese patients, and their overall rate of fat necrosis is comparable to rates reported for free transverse rectus abdominis myocutaneous (TRAM) flaps. Also, increasing body mass index did not seem to affect the rate of delayed complications of the abdominal wall, such as abdominal wall hernia or bulging. Although it was not statistically significant, the authors did observe a trend toward increased wound-healing complications with increasing body mass index. Their data also support the claim that the complete sparing of the rectus abdominis muscles afforded by the DIEP flap avoids abdominal wall fascial bulging or defects often seen in obese TRAM reconstruction patients. Because flap and wound complication rates are similar or superior to those of other autologous tissue reconstruction techniques and the occurrence of abdominal wall defects is all but eliminated, the DIEP flap likely represents the preferred autologous breast reconstruction technique for overweight and obese patients.     

Limb salvage of lower-extremity wounds using free gracilis muscle reconstruction

An extensive series reviewing the benefits and drawbacks of use of the gracilis muscle in lower-extremity trauma has not previously been collected. In this series of 50 patients, the use of microvascular free transfer of the gracilis muscle for lower-extremity salvage in acute traumatic wounds and posttraumatic chronic wounds is reviewed. In addition, the wound size, injury patterns, problems, and results unique to the use of the gracilis as a donor muscle for lower-extremity reconstruction are identified. In a 7-year period from 1991 to 1998, 50 patients underwent lower-extremity reconstruction using microvascular free gracilis transfer at the University of Maryland Shock Trauma Center, Johns Hopkins Hospital, and Johns Hopkins Bayview Medical Center. There were 22 patients who underwent reconstruction for coverage of acute lower-extremity traumatic soft-tissue defects associated with open fractures. The majority of patients were victims of high-energy injuries with 91 percent involving motor vehicle or motorcycle accidents, gunshot wounds, or pedestrians struck by vehicles. Ninety-one percent of the injuries were Gustilo type IIIb tibial fractures and 9 percent were Gustilo type IIIc. The mean soft-tissue defect size was 92.2 cm2. Successful limb salvage was achieved in 95 percent of patients. Twenty-eight patients with previous Gustilo type IIIb tibia-fibula fractures presented with posttraumatic chronic wounds characterized by osteomyelitis or deep soft-tissue infection. Successful free-tissue transfer was accomplished in 26 of 28 patients (93 percent). All but one of the patients in this group who underwent successful limb salvage (26 of 27, or 96 percent) are now free of infection. Use of the gracilis muscle as a free-tissue transfer has been shown to be a reliable and predictable tool in lower-extremity reconstruction, with a flap success and limb salvage rate comparable to those in other large studies.     

被动声学监测技术在西黑冠长臂猿监测中的应用

近年来, 被动声学监测技术被广泛应用于陆生哺乳动物的监测, 它能以较低的价格和非侵入的方式在特定区域进行野生动物无人值守监测, 面临的主要问题是需要人工收回数据和后期数据分析整理较为困难。本研究设计了一套被动声学监测系统用于西黑冠长臂猿(Nomascus concolor)监测, 监测系统在野外由太阳能供电, 使用自研的指向性拾音器阵列采集鸣声数据, 并通过无线网桥实时传输数据至管护局办公楼的服务器进行存储, 通过后台的鸣声数据管理系统辅助研究人员识别鸣声和辨认鸣声来源方向, 简化数据采集和处理流程。该系统在哀牢山国家级自然保护区枇杷箐科研监听点对两个西黑冠长臂猿群体进行了351天的连续监测, 特点为: 系统运行长期稳定, 数据通过无线方式传输便捷高效且不受季节天气影响。指向性拾音器阵列能有效分辨长臂猿鸣声来源方向, 弥补了传统监测设备难以分辨鸣声方向的缺陷。该系统与现有人工监测方法相比在数据采集的持续性、连续性、完整度以及鸣声数据处理智能化和监测成本方面均具有一定优势, 符合西黑冠长臂猿持续长期监测需求, 未来可作为西黑冠长臂猿自动化监测的解决方案进行推广应用。     

Visualization of multidimensional spectra in flow cytometry.

Flow data from a cell sorter have been processed by hardwired circuits which include amplification, discrimination, coincidence requirements, peak sensing and holding, A-D conversion, and a computerized pulse height analysis with storage of the spectra obtained. Two dimensional spectra can be stored directly in memory, on tape and disk. Three and four parametric cellular events can be recorded on line during the flow measurement in a sequential mode on tape for subsequent recall. Simple processing of these data can be performed for displaying of two dimensional projections from these multidimensional spaces based on threshold conditions for the remaining parameters. Interfaced transmission of the stored data to a large scale computer enables more sophisticated data analysis. Data reduction by means of a multidimensional probability analysis has been carried out in order to transfer the spectra to a computerized picture system for display. This system creates perspective two-dimensional images from a three-dimensional data space. Frequency can be converted into grey levels. Hard copy in color (color as the third dimension and color intensity as frequency) simplifies the visualization of multiparametric flow data sets.     

Factors influencing genetic counseling attendance rate: A geographically based study

Abstract

A study of factors influencing genetic counseling attendance rate has been conducted in the Bouches‐du‐Rhône area, in the south of France. In this area, a birth defects monitoring system (Eurocat n°22) annually covers 23,000 births. All the genetic services are delivered by only one genetic center located in Marseilles, and the data collected are computerized. The comparison of these two data bases gives an opportunity to estimate the rate of genetic counseling attendance after the occurrence of an affected stillbirth or live birth. Among the parents of 358 infants born in 1983–84 in this area with a pathology requiring genetic counseling, 226 (63 per cent) attended the Genetic Center within the first year after birth. The rate of attendance is statistically higher (p < 0.01) for the parents who had a stillbirth (78 per cent) than for those who had a live birth (57 per cent). It is also higher (p < 0.01) for the Marseilles maternities group (68 per cent) than for the group outside Marseilles (50 per cent). The referral delays are also analyzed according to malformation etiology and to viability of the child by the eighth day of lue. Besides evaluating a particular genetic center's effectiveness in diffusing information to the public concerned, this work shows that couples’ request is strongly dependent on a psychological need.     

An evolution of communication in postoperative free flap monitoring: using a smartphone and mobile messenger application

For more precise and rapid notification of free flap status between staff members after surgery, the authors used a smartphone and mobile messenger application including multimedia during the initial postoperative period and analyzed the influence of this method for the re-exploration time and survival rate of the flap before and after use. From April of 2010 to September of 2011, 123 consecutive free flaps were reviewed. The authors increased the flap survival rate from 96.2 to 100 percent and increased the threatened flap salvage rate from 50 to 100 percent with this method. The time interval between the first notification of flap compromise and the start of re-exploration was significantly shortened (4.0 versus 1.4 hours). This method not only provided better communication and comprehensive information but also allowed early diagnosis of flap compromise to be actualized at early re-exploration, ultimately increasing flap survival. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.     

Jejunal free autograft: analysis of complications and their resolution

Review of 101 patients who underwent 111 free jejunal autografts has demonstrated an absolute procedural failure rate of 13.5 percent. Salvage reconstruction with a second jejunum was successful in six of nine patients and one third-time jejunum was successful, giving an overall salvage rate of 70 percent. There were 33 patients experiencing pharyngocutaneous fistulas, 20 of whom had been previously irradiated. Of these patients, 15 experienced spontaneous closure and 9 others had successful surgical correction. The mortality rate was 5 percent. Eighty-three percent of patients were restored to adequate per oral alimentation. The jejunum, despite its relatively high complication rate, is an excellent method for pharyngoesophageal reconstruction, expeditiously providing return to function for patients with late-stage disease.     

A computerized system for remote monitoring of subterranean termites near structures.

Sensors comprising wooden stakes painted with conductive circuits of silver particle emulsion were inserted in Sentricon stations in soil near structures. Sensors were wired to a datalogger that was programmed to test for circuit breakage every 2 h and store the data in its memory. A host computer was programmed to access the datalogger through telephone communication lines for data download every 4 d. The computerized monitoring system was tested in three remote sites, and site visits were conducted monthly for 6 mo to examine system accuracy in detecting termite activity. The mean monthly accuracy for the system to correctly report the presence (true positive) or absence of termites (true negative) in the stations was 85%, but the accuracy at 6 mo after system installation ranged from 41 to 79%. Mean sensor longevity, defined as the time for a sensor circuit to break in the absence of termites, was approximately 4.4 mo.