| BackgroundPenis is an important urinary and reproductive organ, and the size of which plays aspecial role in male's physiology and psychology. People usually believe that "bigger isbetter", and many males with a short penis, even normal size, hope to enlarge their penisesthough any surgical or non-surgical approaches. Suspensory ligament dissecting penilelengthening was reported firstly in rectification of congenital epispadias and bladderexstrophy. As further studies in penile suspensory ligament and surrounding structures, theindication of this operation gradually expanded to short penis caused by various congenitalor acquired reasons, such as penile dysplasia, trauma and operations after penile carcinoma.The suspensory ligament dissecting is the more acceptable approach by doctors and patientsbecause of its simple method, lower influence to erection and faster postoperative recovery.Actually, the efficacy and safety of this operation, specifically the operation effect and theinfluence to erection, were the most concerned issues in clinic.In recent years, there were some of disputes in operation effect. Firstly, the actualextended effect of the operation had not reached a consensus. The universal viewpointconsidered that this operation could obtain1~2cm in extended length, but the data indifferent reports existed obvious difference. Secondly, the postoperative satisfaction wasgenerally low in this operation. The reasons were that the patients usually had a higherexpectation preoperatively, but the extended lengths were usually very limited in most cases.Thirdly, the indications of this operation were unclear in clinic. Mondaini et al. reportedthat the men who sought penis lengthening in clinic mostly had a normal penile size. Thesemales usually had a higher expectation in extended length, and the operation effect usuallywould not satisfy them. For these reasons, many researches had conservative attitudes tothis operation. They thought this operation should not be operated extensively, especially tomales with a normal penile size. Actually, it might be helpless to improve the postoperative satisfaction by limiting the indications strictly. The key problem was to make patients'expectation correspond to the actual effect. Thus, an individual forecasting method wouldbe very useful to solve the disputes above-mentioned. An individual forecasting methodneeded a precise prehension of the influence of the regional structures caused by theoperation. However, current researches in the mechanism of the operation were too rough tosatisfy it, because there was lacking of effective study methods yet. Therefore, it wasimportant and urgent to find an effective and precise study method to investigate the precisemechanism for clinical extending and thorough researches of this operation.The penile lengthening procures the extended length through destroying the suspensionsystem of penis, so it is inevitable to influence the physiological function of this systemmore or less. The suspension system of penis contains the fundiform ligament, suspensoryligament and arcuate subpubic ligament, which fixes the corpus penis to the pubicsymphysis and maintains the superducting status in erection. The universal idea of thesuspension system affected by penile lengthening was that the operation brought littleinfluence to the "stability of penile erection", but there was lacking of strict experimentalevidences to support it. Actually there was not related research in the "stability of penileerection" in traditional uronology, even a definite concept. In plastic surgery, the "stabilityof penile erection" in penile lengthening usually was used to indicate whether there was avisible swing or drooping of penis during erection. In this point of view, we suggested thatthe erection angle of penis might be a potential index representing this "stability of penileerection". In order to distinguish with the hemodynamic stability of penile erection, we putforward a concept of "structural stability of penile erection" to represent the previous"stability of penile erection" in penile lengthening. However, there were limited literaturesreferring to erection angle in uronology and andriatria as well. Thus, we firstly had toinvestigate the formation mechanism of erection angle and the relationship of the erectionangle and structural stability of penile erection, in order to study the influence of thesuspension system affected by penile lengthening.MethodThis research consist three parts as follow:1. A total of322patients were diagnosed congenital penile shortness and receivedpartial suspensory ligament release in our department since1988. Firstly all the patients were divide into two groups, named the Modeling Group (200patients) and the CheckingGroup (122patients). Then a two-dimensional model of the suspensory-ligament-releasepenis lengthening was established. For the Modeling Group, a statistical analysis of thepenile length in flaccid and erectile state before and after penis lengthening was carried out,and a forecasting predictive function of increased penile length was derived. At last, theforecasting error of the Modeling Group and the Checking Group were compared.2. The ultrasonograph and MRI were firstly examined in3patients preoperatively andpostoperatively. Then, the corresponding images of ultrasonograph and MRI werecontrasted to investigate the displaying status of dorsal root of penis in ultrasonograph.Finally, the preoperative and postoperative ultrasonograph images were contrasted toinvestigate the precise changes of regional structures caused by the operation.3. The formation mechanism of erection angle was discussed through literature review.Based on the mechanism, a mathematic model of erection angle was established. Then, theintracavernous pressure, erectile angle and length on ex vivo fresh corpse were measured,and the parameter of the model was computed from those measured data.Results1. There is a significant linear correlation between the increased length in flaccid anderectile state (R=0.921, P <0.01), a similar relationship between the extension rate oferection before and after the operation (R=0.803, P <0.01), as well as preoperative flaccidlength and extension rate of erection (R=-0.803, P <0.01). According to the significantlinear correlations shown above, two regression forecasting models are established. Apredictive function of increased flaccid length is derived from the two regressionforecasting models. The effectively forecasting rate is84.5%(the Modeling Group) and87.7%(the Checking Group) when the absolute value of forecasting error is less than1.5cm.2. The ultrasonograph could display the major structures of dorsal root of penis. Afterthe operation, the released corpus cavernosum usually would have a downward (leg side)displacement and an axial prolongation. But a part of released corpus cavernosum washidden in corpore again because of the thickening of presymphysial soft tissue. Thecontributions of the decrease of fixed segment of penis and the axial prolongation ofreleased corpus cavernosum were about1/4and3/4of flaccid absolute extended length respectively.3. The formation mechanism of erection angle mainly depended on the intracavernouspressure, the size of free segment of penis, the distribution of elastic fiber in tunicaalbuginea and the angle between fixed segment of cavernosum and horizontal plane. Theconstructed mathematic model of erection angle could reflect the functional relation of thedeterminative factors shown above. And the parameter of the model could be calculated bythe measured data.Conclusions1. The discovered significant correlation and the established forecasting functionprovide us a model of roughly and individually forecasting the feasible extended penilelength before penis lengthening. But the accuracy of the forecasting model is limited.2. This study is useful to prehension the mechanism and significance of the operation,and might provide some supports in theory and method for forecasting the extended lengthprecisely and individually. In addition, it might degrade the blindness and risk of operativeprocedure.3. The formation mechanism and mathematic model of erection angle we worked couldenrich the theory of penile erection mechanism. Besides, it could be referred for choosing aright treatment for penile lengthening, abnormal erection angle and an evaluation oferection state conveniently and scientifically in clinical practice. |
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