126
|
van Bockel LW, van den Broecke DG, Spliet W, Canninga-van Dijk MR, Kon M. [Five patients with metastasized basal-cell carcinoma]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2003; 147:2231-6. [PMID: 14640062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
During the period 1986-2001, a metastasised basal-cell carcinoma of the head was diagnosed in five patients (a 35-year-old woman and four men aged 40, 44, 54 and 54 years) at the Utrecht University Medical Centre, the Netherlands. Metastases were found in the cervical lymph nodes, the skeleton, the parotid region and the lungs. The tumours were all of the morphoeic or 'wispy' type. The treatment consisted of excision and sometimes radiotherapy. Two patients died, one of whom of a cause unrelated to the tumour, two patients were free of symptoms 24 months after the last treatment and one patient was still being treated with radiotherapy. It is often assumed that basal-cell carcinomas do not metastasised, but a frequency of 0.0028-0.55% is reported in the literature. An important risk factor is the size of the tumour. Surgical excision or Mohs' micrographic surgery is the preferred method of treatment because this allows histological inspection of the excised margins. Due to the low incidence, there are no clear therapeutic guidelines for the treatment of patients with metastasised basal-cell carcinoma.
Collapse
|
127
|
Zonnevijlle EDH, Perez-Abadia G, Stremel RW, Maldonado CJ, Kon M, Barker JH. Dynamic graciloplasty for urinary incontinence: the potential for sequential closed-loop stimulation. Med Eng Phys 2003; 25:755-63. [PMID: 14519348 DOI: 10.1016/s1350-4533(03)00079-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Muscle tissue transplantation applied to regain or dynamically assist contractile functions is known as 'dynamic myoplasty'. Success rates of clinical applications are unpredictable, because of lack of endurance, ischemic lesions, abundant scar formation and inadequate performance of tasks due to lack of refined control. Electrical stimulation is used to control dynamic myoplasties and should be improved to reduce some of these drawbacks. Sequential segmental neuromuscular stimulation improves the endurance and closed-loop control offers refinement in rate of contraction of the muscle, while function-controlling stimulator algorithms present the possibility of performing more complex tasks. An acute feasibility study was performed in anaesthetised dogs combining these techniques. Electrically stimulated gracilis-based neo-sphincters were compared to native sphincters with regard to their ability to maintain continence. Measurements were made during fast bladder pressure changes, static high bladder pressure and slow filling of the bladder, mimicking among others posture changes, lifting heavy objects and diuresis. In general, neo-sphincter and native sphincter performance showed no significant difference during these measurements. However, during high bladder pressures reaching 40 cm H(2)O the neo-sphincters maintained positive pressure gradients, whereas most native sphincters relaxed. During slow filling of the bladder the neo-sphincters maintained a controlled positive pressure gradient for a prolonged time without any form of training. Furthermore, the accuracy of these maintained pressure gradients proved to be within the limits set up by the native sphincters. Refinements using more complicated self-learning function-controlling algorithms proved to be effective also and are briefly discussed. In conclusion, a combination of sequential stimulation, closed-loop control and function-controlling algorithms proved feasible in this dynamic graciloplasty-model. Neo-sphincters were created, which would probably provide an acceptable performance, when the stimulation system could be implanted and further tested. Sizing this technique down to implantable proportions seems to be justified and will enable exploration of the possible benefits.
Collapse
|
128
|
Corten EML, Schellekens PPA, Bleys RLAW, Kon M. The nerve supply to the clavicular part of the pectoralis major muscle: an anatomical study and clinical application of the function-preserving pectoralis major island flap. Plast Reconstr Surg 2003; 112:969-75. [PMID: 12973211 DOI: 10.1097/01.prs.0000076220.71260.c7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to investigate the nerve supply to the clavicular part of the pectoralis major muscle so that the innervation to this part can be maintained in the muscle-preserving pectoralis major island-flap transfer. Although methods have been described that include a limited portion of the muscle while leaving the upper parts undisturbed with an intact motor innervation, reports on anatomical studies of this nerve supply are brief. The distal distribution of the nerves, the spatial relationship to the main vascular pedicle, and the ways to preserve them during surgical procedures remain unclear. Surgically relevant features of the clavicular part of the pectoralis major muscle were studied by dissection. The nerve supply to this part was examined on 11 sides of eight formalin-fixed cadavers. Two fresh cadavers were used for dissection, intraarterial polymer injection, and application of a nerve-preserving surgical technique. In all subjects, a separate nerve innervated the clavicular and upper medial sternocostal portions of the pectoralis major muscle. This nerve arises craniomedial to the main vascular pedicle of the flap and divides into several branches. These branches run in a fascia on the deep surface of the pectoralis major muscle, superficial to the origin and distal course of the vascular pedicle. Most branches to the clavicular part end medial to the coracoid process. The course of the branches to the upper sternocostal part is more medial. Based on their anatomical findings, the authors propose a surgical technique for transfer of the pectoralis major island flap to the head and neck area through a tunnel in the deltopectoral groove, lateral to the origin of the vascular pedicle. Head and neck reconstruction was performed using this technique. The presented method is a muscle-preserving procedure that maintains maximal donor-site function and morphology.
Collapse
|
129
|
van der Heijden EPAB, Kroese ABA, Werker PMN, Kon M, de With MCJ, Bär DPR. Preservation of rat skeletal muscle function during storage for 16 h at 4 degrees C is not improved by pre-storage perfusion. Clin Sci (Lond) 2003; 105:29-37. [PMID: 12580764 DOI: 10.1042/cs20020308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2002] [Revised: 01/17/2003] [Accepted: 02/11/2003] [Indexed: 11/17/2022]
Abstract
The aim of this study was to investigate if the preservation of isolated skeletal muscles for 16 h at 4 degrees C could be improved by pre-storage perfusion (PSP). Two rat muscle models were used: the soleus (SOL) and a posterior strip of the cutaneous trunci (CT). The effects of a 10 min PSP (at 25 degrees C) with University of Wisconsin solution (UW) or HTK-Bretschneider solution (HTK) on muscle function were analysed. The perfusion model was validated by the demonstration that the SOL and CT could be perfused with donor blood, UW and HTK at a flow rate of 0.2 ml x min(-1) x g(-1) muscle for 10 min without any immediate adverse effects on muscle weight, function (maximum tetanus tension) and cytoarchitecture (multivariate analysis of variance, P >0.05; n =6). For each muscle type and for each solution, six perfused and six non-perfused muscles were stored for 16 h at 4 degrees C. In the perfused groups, the storage and perfusion solution were matched. For both muscle types, the function (maximum tetanus tension), weight and cytoarchitecture of pre-storage perfused muscles was not preserved any better than that of non-perfused muscles, irrespective of the solution used (multivariate analysis of variance, P >0.05). We conclude that PSP for 10 min with UW and HTK does not improve the preservation of function of rat skeletal muscles during storage for 16 h at 4 degrees C.
Collapse
|
130
|
van der Steen LPE, Hage JJ, Kon M, Mazzola R. Reliability of a structured method of selecting abstracts for a plastic surgical scientific meeting. Plast Reconstr Surg 2003; 111:2215-22. [PMID: 12794462 DOI: 10.1097/01.prs.0000061092.88629.82] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
There is no generally accepted method for assessing abstracts that are submitted for a medical scientific meeting. This article describes the development and prospective evaluation of such a method applied to the 220 abstracts submitted for the 2000 Annual Meeting of the European Association of Plastic Surgeons. Structured abstracts were evaluated in three categories: aesthetic surgery, basic research, and clinical study. Each anonymous abstract was assessed separately by 10 reputable European plastic surgeons. These reviewers used a structured rating questionnaire which resulted in a score given by each reviewer to each abstract between -6 and +6. The scores of all 10 reviewers were added for each abstract, and the papers were accepted in each of the three categories on the basis of this abridged score. To evaluate the reliability of this structured method of selection, the interrater agreement among the reviewers was tested by means of kappa analysis and the Cronbach alpha coefficient. The kappa values for agreement among reviewers regarding acceptability of abstracts were low, but the alpha coefficient indicated an acceptable degree of reliability of the average reviewers' ratings for all categories. Using a structured questionnaire can be helpful in the objective assessment of abstracts for a scientific meeting and may facilitate comparison of abstracts. Meritocratic dichotomy of abstracts by the reviewers is advocated to further improve reliability of the rating. Even though reliability generally increases with the number of reviewers, the annual increase of submitted abstracts may necessitate a decrease in the number of reviewers for each abstract.
Collapse
|
131
|
Nagelvoort RWK, Kon M, Schuurman AH. Proximal row carpectomy: a worthwhile salvage procedure. SCANDINAVIAN JOURNAL OF PLASTIC AND RECONSTRUCTIVE SURGERY AND HAND SURGERY 2003; 36:289-99. [PMID: 12477088 DOI: 10.1080/028443102320791842] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
After proximal row carpectomy 11 patients were evaluated in the six ensuing years for pain relief, satisfaction, ranges of movement, grip and precision grip strength, and radiographic picture. The median follow-up period was 3.1 years (range 4 months to 6 years). They were operated on for scaphoid non-union with radiocarpal arthritis, late stage Kienböck's disease, chronic scapholunate dissociation and scapholunate advanced collapse wrist deformity. The mean disabilities of the arm, shoulder and hand (DASH) scoring list, which indicates the patient's degree of disability 28% (range 2%-64%) of maximum disability for the function and symptom score. Flexion, extension, and radial and ulnar deviation of the wrist improved to 47% (range 21%-76%), 67% (range 41%-81%), 39% (range 25%-55%), and 81% (range 44%-90%) of the opposite wrist. Mean grip strength, 70% (range 22%-117%) of the opposite site, while the three precision grips improved between 72% and 79%. A review of previous studies of proximal row carpectomy showed results comparable with those of our study. Compared with other treatments, it is a dependable, relatively-simple procedure that gives reliable relief of pain, preserves functional ranges of movement and grip strength, and allows most patients to return to work.
Collapse
|
132
|
Overgoor MLE, Carroll SM, Papanicolau G, Carroll CMA, Ustüner TET, Stremel RW, Anderson GL, Franken RJPM, Kon M, Barker JH. Can angiogenesis induced by chronic electrical stimulation enhance latissimus dorsi muscle flap survival for application in cardiomyoplasty? Plast Reconstr Surg 2003; 111:178-88. [PMID: 12496579 DOI: 10.1097/01.prs.0000034920.59319.50] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In cardiomyoplasty, the latissimus dorsi muscle is lifted on its primary neurovascular pedicle and wrapped around a failing heart. After 2 weeks, it is trained for 6 weeks using chronic electrical stimulation, which transforms the latissimus dorsi muscle into a fatigue-resistant muscle that can contract in synchrony with the beating heart without tiring. In over 600 cardiomyoplasty procedures performed clinically to date, the outcomes have varied. Given the data obtained in animal experiments, the authors believe these variable outcomes are attributable to distal latissimus dorsi muscle flap necrosis. The aim of the present study was to investigate whether the chronic electrical stimulation training used to transform the latissimus dorsi muscle into fatigue-resistant muscle could also be used to induce angiogenesis, increase perfusion, and thus protect the latissimus dorsi muscle flap from distal necrosis. After 14 days of chronic electrical stimulation (10 Hz, 330 microsec, 4 to 6 V continuous, 8 hours/day) of the right or left latissimus dorsi muscle (randomly selected) in 11 rats, both latissimus dorsi muscles were lifted on their thoracodorsal pedicles and returned to their anatomical beds. Four days later, the resulting amount of distal flap necrosis was measured. Also, at predetermined time intervals throughout the experiment, muscle surface blood perfusion was measured using scanning laser Doppler flowmetry. Finally, latissimus dorsi muscles were excised in four additional stimulated rats, to measure angiogenesis (capillary-to-fiber ratio), fiber type (oxidative or glycolytic), and fiber size using histologic specimens. The authors found that chronic electrical stimulation (1) significantly (p < 0.05) increased angiogenesis (mean capillary-to-fiber ratio) by 82 percent and blood perfusion by 36 percent; (2) did not reduce the amount of distal flap necrosis compared with nonchronic electrical stimulation controls (29 +/- 5.3 percent versus 26.6 +/- 5.1 percent); (3) completely transformed the normally mixed (oxidative and glycolytic) fiber type distribution into all oxidative fibers; and (4) reduced fiber size in the proximal and middle but not in the distal segments of the flap. Despite the significant increase in angiogenesis and blood perfusion, distal latissimus dorsi muscle flap necrosis did not decrease. This might be because of three reasons: first, the change in muscle metabolism from anaerobic to aerobic may have rendered the muscle fibers more susceptible to ischemia. Second, because of the larger diameter of the distal fibers in normal and stimulated latissimus dorsi muscle, the diffusion distance for oxygen to the center of the distal fibers is increased, making fiber survival more difficult. Third, even though angiogenesis was significantly increased in the flap, cutting all but the single vascular pedicle resulted in the newly formed capillaries not receiving enough blood to provide nourishment to the distal latissimus dorsi muscle. The authors' findings indicate that chronic electrical stimulation as tested in these experiments could not be used to prevent distal latissimus dorsi muscle flap ischemia and necrosis in cardiomyoplasty.
Collapse
|
133
|
Nagelvoort RWK, Hulstaert PF, Kon M, Schuurman AH. [Necrotising fasciitis and myositis as serious complications after liposuction]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2002; 146:2430-5. [PMID: 12518522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Three days after liposuction of the lower abdomen, a 41-year-old woman was admitted for toxic shock-like syndrome with necrotising fasciitis and myositis, caused by Lancefield-group-A beta-haemolytic streptococci. The patient was treated by radical debridement of the skin, subcutis, fasciae and part of the pectoral muscle, plus antibiotics. Postoperatively she required artificial respiration for respiratory insufficiency. One week after the operation the wound was covered by transplantation of autologous skin. The patient survived, but was seriously disfigured. Necrotising fasciitis is a progressive soft-tissue infection, characterised by widespread necrosis of the superficial and deep fascia, often associated with severe systemic toxic reactions. Unless quickly recognised and aggressively treated, the course is often fatal. Due to the absence of cutaneous findings in the early stages, diagnosis is difficult. Important diagnostic aids are routine laboratory tests, contrast-MRI and a combination of the finger test and frozen-section biopsy. Treatment consists of early radical debridement, broad-spectrum antibiotics and supportive care. In a later stage, soft-tissue reconstruction with autografts or artificial skin grafts and skin transposition can be performed.
Collapse
|
134
|
Wan C, Maldonado C, Papanicolaou G, Anderson GL, Overgoor M, Kon M, Barker JH. Reducing the vascular delay period in latissimus dorsi muscle flaps for use in cardiomyoplasty. Plast Reconstr Surg 2002; 109:1630-7. [PMID: 11932607 DOI: 10.1097/00006534-200204150-00021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Although the mechanism by which vascular delay benefits skin flaps is not completely understood, this topic has been extensively studied and reported on in the literature. In contrast, little has been documented about the effects of vascular delay in skeletal muscle flaps. Recent animal studies tested the effectiveness of vascular delay to enhance latissimus dorsi muscle flap viability for use in cardiomyoplasty and found that it prevented distal flap necrosis. However, these studies did not define the optimal time period necessary to achieve this beneficial effect. The purpose of this study was to determine how many days of "delay" can elicit the beneficial effects of vascular delay on latissimus dorsi muscle flaps. To accomplish this, 90 latissimus dorsi muscles of 45 male Sprague-Dawley rats were randomly subjected to vascular delay on one side or a sham procedure on the other. After predetermined delay periods (0, 3, 7, 10, and 14 days) or a sham procedure, all latissimus dorsi muscles were elevated as single pedicled flaps based only on their thoracodorsal neurovascular pedicle. Latissimus dorsi muscle perfusion was measured using a Laser Doppler Perfusion Imager just before and immediately after flap elevation. The muscles were then returned to their original vascular beds, isolated from adjacent tissue with Silastic film, sutured into place to maintain their original size and shape, and left there for 5 days. After 5 days, the latissimus dorsi muscle flaps were dissected free, scanned again (Laser Doppler Perfusion Imager-perfusion measurements), and the area of distal necrosis was measured using digitized planimetry of magnified images. The authors' results showed that delay periods of 3, 7, 10, and 14 days significantly increased (p < 0.05) blood perfusion and decreased (p < 0.05) distal flap necrosis when compared with sham controls. On the basis of these findings, the authors conclude that in their rat latissimus dorsi muscle flap model the beneficial effects of vascular delay are present as early as 3 days. If these findings also hold true in humans, they could be useful in cardiomyoplasty by allowing surgeons to shorten the amount of time between the vascular delay procedure and the cardiomyoplasty procedure in these very sick patients.
Collapse
|
135
|
Zonnevijlle EDH, Abadia GP, Somia NN, Kon M, Barker JH, Koenig S, Ewert DL, Stremel RW. A technique for sequential segmental neuromuscular stimulation with closed loop feedback control. J INVEST SURG 2002; 15:91-9. [PMID: 12028619 DOI: 10.1080/08941930290085813] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
In dynamic myoplasty, dysfunctional muscle is assisted or replaced with skeletal muscle from a donor site. Electrical stimulation is commonly used to train and animate the skeletal muscle to perform its new task. Due to simultaneous tetanic contractions of the entire myoplasty, muscles are deprived of perfusion and fatigue rapidly, causing long-term problems such as excessive scarring and muscle ischemia. Sequential stimulation contracts part of the muscle while other parts rest, thus significantly improving blood perfusion. However, the muscle still fatigues. In this article, we report a test of the feasibility of using closed-loop control to economize the contractions of the sequentially stimulated myoplasty. A simple stimulation algorithm was developed and tested on a sequentially stimulated neo-sphincter designed from a canine gracilis muscle. Pressure generated in the lumen of the myoplasty neo-sphincter was used as feedback to regulate the stimulation signal via three control parameters, thereby optimizing the performance of the myoplasty. Additionally, we investigated and compared the efficiency of amplitude and frequency modulation techniques. Closed-loop feedback enabled us to maintain target pressures within 10% deviation using amplitude modulation and optimized control parameters (correction frequency = 4 Hz, correction threshold = 4%, and transition time = 0.3 s). The large-scale stimulation/feedback setup was unfit for chronic experimentation, but can be used as a blueprint for a small-scale version to unveil the theoretical benefits of closed-loop control in chronic experimentation.
Collapse
|
136
|
Stadelmann WK, Bardoel JW, Perez-Abadia G, Majzoub RK, Maldonado C, Tobin GR, Kon M, Barker JH. Dynamic rectus abdominis muscle flap for intestinal stomal continence: a systematic approach. Microsurgery 2002; 21:248-55. [PMID: 11746556 DOI: 10.1002/micr.1048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Several attempts to create a continent stomal sphincter using dynamic myoplasty with limited success have been reported. Denervation atrophy and early muscle fatigue have plagued all reported attempts to make a continent stoma a reality. To address this problem in a series of experiments, we designed a stomal sphincter using the most caudal segment of the rectus abdominis muscle. Then, we performed a study to determine whether a sphincter created with a rectus abdominis muscle island flap could maintain stomal continence in the short term. We found that when stimulated using two different electrical stimulation protocols, in all cases the rectus abdominis muscle sphincter generated peak pressures well above those needed to maintain stomal continence (60 mm Hg). All sphincters were able to maintain stomal continence at all intraluminal bowel pressures tested. We found one of these protocols to be far superior and reached 4 hours of stomal continence after 8 to 10 weeks of electrical stimulation.
Collapse
|
137
|
Perez-Abadia G, Van Aalst VC, Palacio MM, Werker PM, Ren X, Van Savage J, Fernandez AG, Kon M, Barker JH. Gracilis muscle neosphincter for treating urinary incontinence. Microsurgery 2002; 21:271-80. [PMID: 11746559 DOI: 10.1002/micr.1051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The purpose of this study was to test the anatomical and functional feasibility of using a gracilis muscle free flap to create a urinary sphincter. Anatomical studies were performed in 12 human cadavers and short-term (n = 7) and long-term (n = 8) functional studies were performed in dogs. In the short-term functional studies, the left gracilis muscle was transferred into the pelvis and wrapped around the urethra and the right gracilis muscle was wrapped around a stent. A cuff electrode was placed on the muscle's nerve pedicle and used to stimulate the neosphincter while peak pressure, fatigue rate, and perfusion measurements were performed. In the long-term functional studies, intramuscular electrodes were inserted into the neosphincter to stimulate the flap. The flaps were wrapped around the urethra and dogs were followed for 16 weeks, during which time urodynamic measurements were performed. Our anatomical studies demonstrated that the gracilis muscle free flap could be transferred into the pelvis to create a urinary neosphincter. Our short-term functional study demonstrated that gracilis muscle free-flap function and perfusion were not compromised by transfer. In our long-term functional study, all neosphincters provided bladder outlet resistance pressures consistent with continence. Our anatomical, short-term, and long-term functional studies indicate that a gracilis muscle free-flap neosphincter is an effective procedure for treating urinary incontinence.
Collapse
|
138
|
Koh TW, Parker KH, Kon M, Pepper JR. Changes in aortic rotational flow during cardiopulmonary bypass studied by transesophageal echocardiography and magnetic resonance velocity imaging: a potential mechanism for atheroembolism during cardiopulmonary bypass. Heart Vessels 2001; 16:1-8. [PMID: 11829212 DOI: 10.1007/pl00007273] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The human aorta is a curved conduit with a complex three-dimensional geometry. The curvature influences axial velocity distribution and introduces transverse velocity components. Rotational flow in the aorta can be demonstrated during normal pulsatile flow using transesophageal echocardiography. Cardiopulmonary bypass may affect the pattern of rotational flow in the aorta and thus influence the generation of atheroemboli. We investigated rotational flow in the descending aorta using color flow mapping and pulse-wave Doppler on transesophageal echocardiography before and during cardiopulmonary bypass. We correlated our findings with magnetic resonance velocity imaging in a model of a human aortic arch connected to a cardiopulmonary bypass circuit. Before cardiopulmonary bypass, rotational flow in the descending aorta was seen in 37 of 40 patients (93%). In the majority of these patients, rotational flow was in the clockwise direction during systole, looking in the direction of flow (30 of 37 patients, 81%, P < 0.01 vs counterclockwise rotation). During cardiopulmonary bypass, there were almost equal numbers of patients with clockwise (18 patients) and counterclockwise rotation (19 patients). Forty-seven percent of patients with clockwise rotation before cardiopulmonary bypass developed reversal in the direction of rotation to counterclockwise during cardiopulmonary bypass. Twenty-nine percent of patients with counterclockwise rotation developed reversal of the direction of rotation during cardiopulmonary bypass. The transverse velocity component increased during cardiopulmonary bypass regardless of the direction of rotation. We also demonstrated clockwise rotation in the descending aorta of a human aortic arch model connected to a cardiopulmonary bypass circuit using magnetic resonance velocity mapping. Before cardiopulmonary bypass, rotation was predominantly clockwise, while during cardiopulmonary bypass, there was no preferred direction of rotation. The geometry of the aorta, which is fairly constant in all patients, imposes handedness to aortic flow before cardiopulmonary bypass. However, during cardiopulmonary bypass, other extrinsic factors such as aortic cannula orientation may influence the direction of rotation. The change in direction of rotational flow and increase in its transverse velocity component during cardiopulmonary bypass may have implications for atheroembolism and arterial branch perfusion during extended periods of non-pulsatile flow.
Collapse
|
139
|
Maekawa K, Kon M, Araya K, Matsumoto T. Phylogeny and biogeography of wood-feeding cockroaches, genus Salganea Stål (Blaberidae: Panesthiinae), in Southeast Asia based on mitochondrial DNA sequences. J Mol Evol 2001; 53:651-9. [PMID: 11677625 DOI: 10.1007/s002390010252] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2001] [Accepted: 04/20/2001] [Indexed: 11/27/2022]
Abstract
Molecular phylogenetic relationships among 25 species of the wood-feeding cockroach belonging to the genus Salganea Stål (Panesthiinae; Blaberidae) in Southeast Asia were analyzed based on the DNA sequence of the complete mitochondrial cytochrome oxidase II (COII) gene. Most basal relationships among species of Salganea are poorly resolved by both neighbor-joining and nonweighted parsimony analyses, suggesting the possibility of a hard polytomy due to a rapid and potentially simultaneous radiation early in the history of the genus. For more apical relationships, however, some interesting phylogenetic relationships were recognized. The monophyly of the two species groups, morio and foveolata, the former of which is distributed mainly in the Sunda lands (containing the Malay Peninsula, Sumatra, Java, and Borneo), whereas the latter is Sulawesi endemic, was strongly supported. Based on the inferred phylogenetic patterns and recent palaeogeographic scenario for Southeast Asia, it is suggested that a radiation of Salganea species occurred in Southeast Asia presumably in the early Tertiary, and several barriers against dispersal and gene flow, such as the formation of straits or high mountains, have arisen from the middle Tertiary.
Collapse
|
140
|
Nagelvoort RW, Kon M, Schuurman AH. [Proximal row carpectomy: a 'salvage' procedure for radio-carpal arthritis of the wrist]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2001; 145:1913-7. [PMID: 11675971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
In 4 patients, a woman aged 46 years, and 3 men aged 58, 28 and 60 years, respectively, a proximal row carpectomy was done for pain and loss of function due to scapho-lunate dissociation, scaphoid nonunion, Kienböck's disease and scapho-lunate advanced collapse wrist deformity (bilateral). Pain relief was achieved post-operatively in all patients, allowing patients to return to their previous work and activities. Proximal row carpectomy involves the removal of the os scaphoideum, the os lunatum and the os triquetrum. This improves wrist extension and ulnar deviation. Intensive postoperative treatment is essential to achieve good mobility and strength.
Collapse
|
141
|
Kon M, O'Brien WJ, Rasmussen ST, Asaoka K. Mechanical properties of glass-only porcelains prepared by the use of two feldspathic frits with different thermal properties. J Dent Res 2001; 80:1758-63. [PMID: 11669489 DOI: 10.1177/00220345010800081501] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Low- and non-leucite-containing commercial porcelains with low firing temperatures have become popular. However, improving the strength of glass porcelains is difficult. The purpose of this study was to determine if dispersed glass particles could be used as a reinforcing agent for an all-glass porcelain. We produced 3 feldspathic glasses (high-fusing, medium-fusing, low-fusing) by melting powders consisting of potassium-feldspar and 0, 5, or 20 mass% Na2O, respectively. For high-fusing, medium-fusing, and low-fusing feldspathic glasses, the deformation temperatures were 945 degrees C, 647 degrees C, and 518 degrees C, and the thermal expansion coefficient values were 8.6 x 10(-6)/degrees C, 10.3 x 10(-6)/degrees C, and 13.4 x 10(-6)/degrees C between 25 degrees C and the glass-transition temperature, respectively. The high-fusing-glass (or medium-fusing-glass) powders were mixed with low-fusing-glass powders before being fired into test specimens. The mean flexural strength and fracture toughness (K1C) of 3 single-glass porcelains ranged from 57 to 63 MPa and from 0.68 to 0.73 MPa m(1/2), respectively, presenting no significant differences in one-way ANOVA. However, the flexural strength of 50% high-fusing-glass + 50% low-fusing-glass porcelain was 114 MPa (p < 0.05) and K1C was 1.2 MPa m(1/2) (p < 0.05). Microcracks were observed with a back-scattered scanning electron microscope and were associated with the high- (or medium-) fusing glass particles, suggesting residual stress in the low-fusing-glass matrix due to a coefficient of thermal expansion mismatch between the dispersed glass particles and the matrix glass. The dispersing glass particles appeared to act as a reinforcing agent for strengthening a glassy porcelain.
Collapse
|
142
|
Kawano F, Kon M, Kobayashi M, Miyai K. Reinforcement effect of short glass fibers with CaO- P(2)O(5) -SiO(2) -Al(2)O(3) glass on strength of glass-ionomer cement. J Dent 2001; 29:377-80. [PMID: 11472811 DOI: 10.1016/s0300-5712(01)00023-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVES A high strength glass-ionomer (not resin-modified) cement was developed using short fibers of CaO--P(2)O(5)--SiO(2)--Al(2)O(3) (CPSA) glass. The purpose of this study was to clarify the effect of the CPSA short fibers contained in the flexural strength of the glass-ionomer cement. METHOD The 40 mass% short fibers of CPSA glass were added to the powder of commercial glass-ionomer cement. Beam specimens of set cement (25 x 2 x 2 mm) were prepared for measuring the flexural strength (FS). The specimens of set commercial glass-ionomer cement (GI) were used for comparison with glass ionomer cement with CPSA (FRGI). Half of all specimens were thermocycled in water for 60s of dwell time at 4 and 60 degrees C for 2500, 5000, and 10,000 cycles. The other specimens were stored in water at 37 degrees C as a control. The measurements were statistically analyzed using ANOVA. RESULTS The initial FS of FRGI was 18.1 and that of GI was 7.7 MPa. After thermocycling, the mean FS ranged from 19.3 to 26.3 MPa and 9.8 to 11.1 MPa for FRGI and GI, respectively. After storage in water, the mean FS of FRGI and GI ranged from 20.4 to 25.9 MPa and 9.4 to 10.1 MPa, respectively. CONCLUSION These findings suggested that glass-ionomer cement reinforced with CPSA short fibers maintains a higher strength than the conventional cement after aging.
Collapse
|
143
|
Abstract
A total of 101 consecutive abdominoplasty patients were reviewed retrospectively. Of these, 14 male (mean age at time of operation, 34.3 years; range, 23 to 53 years) and 72 female (mean age at time of operation, 38.9 years; range, 19 to 64 years) patients had adequate documentation for inclusion in this study. Complications were recorded as either wound complications (wound infection, partial wound dehiscence, seroma, hematoma, and skin edge necrosis) or complications after surgery (deep vein thrombosis, pulmonary emboli, ileus, sensibility disorder of the skin of the thighs, and death). The complications were subsequently correlated for sex, race, the patient's age at surgery, body mass index before surgery, and the seniority of the surgeon. Nine male patients (64.3 percent) and 11 female patients (15.3 percent) had wound complications. Almost 10 percent of our patients sustained an injury to the lateral cutaneous nerve of the thigh. Male patients should be informed about their possible higher risk of complications, and special attention must be given by the surgeon to the prevention of such complications.Moreover, specific attention must be given to the preservation of the lateral cutaneous nerves of the thigh in both male and female patients undergoing abdominoplasties.
Collapse
|
144
|
van Uchelen JH, Kon M, Werker PM. The long-term durability of plication of the anterior rectus sheath assessed by ultrasonography. Plast Reconstr Surg 2001; 107:1578-84. [PMID: 11335840 DOI: 10.1097/00006534-200105000-00046] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to assess the long-term durability of a standard vertical plication of the anterior rectus sheath. For this purpose, 70 women who had undergone this procedure as part of an abdominoplasty were sent a questionnaire, their records were studied, and they were invited back to the clinic for an examination using ultrasound. A total of 63 patients returned the questionnaire, and 40 were willing to attend a follow-up consultation and ultrasound investigation. The presence of rectus diastasis was assessed by ultrasound (a real time scanner with a 7.5-MHz linear probe). The study showed that after a follow-up of 32 to 109 months (mean, 64 months), standard plication of the abdominal wall with absorbable material led to residual or recurrent diastasis in 40 percent of the patients. It also confirmed that vertical plication only is not enough to improve the waistline and may eventually lead to epigastric bulging.
Collapse
|
145
|
Franken RJ, Gupta SC, Banis JC, Thomas SV, Derr JW, Klein SA, Kon M, Barker JH. Microsurgery without a microscope: laboratory evaluation of a three-dimensional on-screen microsurgery system. Microsurgery 2001; 16:746-51. [PMID: 9148102 DOI: 10.1002/micr.1920161109] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In microvascular surgery, procedures may be both technically and physically demanding. Precise movements sustained over long hours in addition to typically compromised surgeon and assistant positioning lead quickly to physical and mental fatigue. Many of the positioning problems encountered are related to the fact that the eyes of the surgeon must be continually fixed to the microscope eyepieces. This study explores a possible solution: a microscope system that eliminates the need to view the operative field through the microscope eyepieces. A Three-dimensional On-screen Microsurgical System (TOMS) was used and contrasted with conventional operative microvascular surgery in the laboratory setting. The surgeon's comfort, his ability to instruct microsurgical technique, pertinent technological performance, and the procedure itself were evaluated using a standardized questionnaire. Based on data collected in this study, we conclude that divorcing the surgeon's eyes from the microscope eyepieces using the TOMS may make prolonged microvascular procedures less physically demanding and may increase the comfort level of both the surgeon and his assistant, although refinements to the technology are required.
Collapse
|
146
|
Franken RJ, Werker PM, Peter FW, Overgoor ML, Wang WZ, Anderson GL, Schuschke DA, Banis JC, Kon M, Barker JH. Microcirculatory changes following different temperature washouts in a free flap model. Microsurgery 2001; 19:214-22. [PMID: 10413786 DOI: 10.1002/(sici)1098-2752(1999)19:5<214::aid-micr2>3.0.co;2-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In spite of the extensive experimental work on vascular washout in free flap surgery, an optimal temperature for the washout solution has not been established. This study was designed to determine the effect of the washout solution temperature on the degree to which the microcirculation is cleared of blood. The cremaster muscle flap in the rat was used, in which the microcirculation can be directly viewed and the presence of blood and perfusion parameters within various vessels can be measured during and after washout. Washout was started with a single, high-pressure infusion and continued at 130 mmHg for 15 minutes. The temperature of the washout solution was either 2-3, 20-22, or 35 degrees C. In all three groups, washout cleared the microcirculation almost completely within the first minute. However, we observed that a cold or room temperature washout cleared the microcirculation more completely than a warm washout did. The temperature of the washout solution did not effect post washout capillary perfusion and/or arterial diameters.
Collapse
|
147
|
Borg ED, Werker PM, Franken RJ, Borst C, Kon M. Effect of vascular freezing on the histopathology of dissected small vessels in the rat: vascular freezing does induce intimal hyperplasia in arteries and veins. Microsurgery 2001; 20:331-6. [PMID: 11119288 DOI: 10.1002/1098-2752(2000)20:7<331::aid-micr4>3.0.co;2-n] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Intimal hyperplasia is the primary response of a vessel wall after injury. It may be the single most significant factor affecting long-term patency. The purpose of this study was to find out whether freeze injury, inflicted on rat microvessels, would be followed by intimal hyperplasia. Toward this aim, we exposed the superficial femoral vessels in the rat. On one side they were frozen using liquid nitrogen spray. The other side was dissected as the control. Vessel segments, harvested immediately and after 1, 2, 3, and 5 months, were studied light microscopically for the occurrence and content of intimal hyperplasia. In the arteries a considerable intimal hyperplasia was found within a 4-week interval, persisting for at least 5 months, as a result of the freeze injury. In the veins, the intimal hyperplasia was much less marked but was nevertheless demonstrable. These findings are not in agreement with earlier studies, in which freezing of injured rat microarteries with liquid nitrogen spray was followed by complete regeneration of the vessel wall, without intimal hyperplasia taking place. The factors contributing to these differences are discussed. It is concluded that freezing of a vessel wall is followed by intimal hyperplasia, which is part of the normal healing process.
Collapse
|
148
|
Hulscher JB, te Velde EA, Schuurman AH, Hoogendoorn JM, Kon M, van der Werken C. Arthrodesis after osteosynthesis and infection of the ankle joint. Injury 2001; 32:145-52. [PMID: 11223046 DOI: 10.1016/s0020-1383(00)00156-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nineteen patients with a severely infected ankle joint after previous osteosynthesis were treated with arthrodesis in our institution. Their notes and X-rays were reviewed. Goals of treatment were eradication of infection by aggressive débridement of infected tissues, obtaining adequate soft-tissue coverage, preservation/restoration of bonelength, and finally consolidation of the arthrodesis. Thirteen men and six women were treated, with a median age of 46 (17-69) years. Arthrodesis took place after a median of 6 months (0.5-40) post-accident, and after one to six earlier operative procedures. Primarily there had been four bimalleolar, five trimalleolar and ten pilon tibial fractures. Fifteen fractures were open with severe soft tissue damage. Seven free muscle transfers were performed, and ten cancellous bone graftings. Finally 29 attempts at arthrodesis were performed. Ultimately we had to perform two amputations. After a mean follow up of 3.5 years, one patient has an aseptic but asymptomatic pseudarthrosis, for which no further surgery is scheduled. Sixteen extremities are free from infection while full weightbearing is possible. The limb-threatening problem of deep infection after osteosynthesis of an ankle fracture can be resolved by consistent but prolonged treatment. After successful arthrodesis a weightbearing extremity without infection remains in the majority of cases.
Collapse
|
149
|
Bardoel JW, Stadelmann WK, Perez-Abadia GA, Galandiuk S, Zonnevijlle ED, Maldonado C, Stremel RW, Tobin GR, Kon M, Barker JH. Dynamic rectus abdominis muscle sphincter for stoma continence: an acute functional study in a dog model. Plast Reconstr Surg 2001; 107:478-84. [PMID: 11214064 DOI: 10.1097/00006534-200102000-00025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Fecal stomal incontinence is a problem that continues to defy surgical treatment. Previous attempts to create continent stomas using dynamic myoplasty have had limited success due to denervation atrophy of the muscle flap used in the creation of the sphincter and because of muscle fatigue resulting from continuous electrical stimulation. To address the problem of denervation atrophy, a stomal sphincter was designed using the most caudal segment of the rectus abdominis muscle, preserving its intercostal innervation as well as its vascular supply. The purpose of the present study was to determine whether this rectus abdominis muscle island flap sphincter design could maintain stomal continence acutely. In this experiment, six dogs were used to create eight rectus abdominis island flap stoma sphincters around a segment of distal ileum. Initially, the intraluminal stomal pressures generated by the sphincter using different stimulation frequencies were determined. The ability of this stomal sphincter to generate continence at different intraluminal bowel pressures was then assessed. In all cases, the rectus abdominis muscle sphincter generated peak pressures well above those needed to maintain stomal continence (60 mmHg). In addition, each sphincter was able to maintain stomal continence at all intraluminal bowel pressures tested.
Collapse
|
150
|
Kobayashi M, Kon M, Miyai K, Asaoka K. Strengthening of glass-ionomer cement by compounding short fibres with CaO-P2O5-SiO2-Al2O3 glass. Biomaterials 2000; 21:2051-8. [PMID: 10966014 DOI: 10.1016/s0142-9612(00)00096-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to determine if short fibres of CaO-P2O5-SiO2-Al2O3 (CPSA) glass possessing a particular aspect ratio (length/diameter) could be used as a reinforcing agent for glass-ionomer cement. The powder of a commercial glass-ionomer cement (not resin modified) was mixed with variously sized CPSA glass short fibres before mixing with the liquid of the glass-ionomer cement. The mixed powders containing 60 mass% CPSA glass short fibres (diameter, 9.7 +/- 2.1 microm, aspect ratio, 5.0 +/- 0.9) obtained maximum values of 18 and 35 MPa for the diametral tensile strength (DTS) and flexural strength (FS) of set cements, respectively, after 24 h. These DTS and FS values were 1.8 and 4.5 times larger, respectively, than those of the set glass-ionomer cement not containing short fibres. Moreover, it was found that the addition of CPSA glass short fibres was remarkably more effective in the strengthening than electric glass (a typical glass fibre) short fibres. The results suggested that the CPSA glass short fibres acted as a reinforcing agent for strengthening the glass-ionomer cement, because of the shape of short fibres and reactivity between the mixing liquid and short fibres.
Collapse
|