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Modified pudendal-thigh flap for correction of penoscrotal transposition
ELSEVIER
MODIFIED JAY
B.
PUDENDAL-THIGH PENOSCROTAL LEVY,
MICHAEL
F. DARSON,
Objectives. In patients with penoscrotal deficiency of skin on the proximal penile Methods. We describe a new operation of incomplete penoscrotal transposition. Results. This procedure has been used been achieved in each patient. Conclusions. The flaps provide a reliable of postoperative penoscrotal fusion and sion-free second-stage urethroplasty. rights reserved.
ULDIS
BITE,
AND
STEPHEN
OF
A. KRAMER
ABSTRACT transposition, an occasional postoperative problem has been a shaft that results in penoscrotal fusion and tethering. using a modified neurovascular pudendal-thigh flap for correction in 6 children,
and an excellent
cosmetic
and functional
result has
blood supply, maintain normal innervation, and correct the problem tethering. This technique preserves sufficient penile skin for a tenUROLOGY 50: 597-600, 1997. 0 1997, Elsevier Science Inc. All
P
enoscrotal transposition is an unusual anomaly of the external genitalia that is characterized by malposition of the penis in relation to the scrotum. Embryologically, penoscrotal transposition occurs when the labioscrotal swellings fail to migrate caudally at 9 to 10 weeks of gestation and fuse anteriorly or laterally to the genital tubercle. The transposition may be complete or incomplete. Patients with incomplete penoscrotal transposition usually have associated proximal hypospadias with severe chordee. Standard techniques include mobilization of the two halves of the scrotum as rotational advancement flaps with relocation of the scrotum in the normal dependent position.1%2 An occasional problem with these repairs is a deficiency of skin on the proximal penile shaft that produces tethering at the junction of the scrotum and base of the penis. We have used a modified neurovascular pudendal-thigh flap for correction of incomplete penoscrotal transposition. The bilateral flaps provide a reliable blood supply, maintain normal innervation, and correct the problem of penoscrotal fusion
From the Department of Urology and the Division of Plastic Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota Repr-int requests: Stephen A. Kramer, M.D., Department of Urology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 Submitted: March 27, 1997, accepted: June 3, 1997 0 1997, ELSEVIER SCIENCE ALL RIGHTS RESERVED
FLAP FOR CORRECTION TRANSPOSITION
and tethering postoperatively. serves sufficient penile skin ond-stage urethroplasty. SURGICAL
This technique for a tension-free
presec-
TECHNIQUE
The procedure is performed with the patient in the lithotomy position. Hemicircumferential incisions are made bilaterally above the scrotum to mobilize the scrotal halves as rotational advancement flaps (Fig. 1). A plane of dissection is developed subcutaneously, and the scrotal pedicles are transposed inferior to the penis. This recreates the normal anatomic configuration of the penis and scrotum. Most of these children have descended testes. However, mobilization of the spermatic cords is often necessary to bring the testes down into the relocated dependent scrotal position. Although these rotational flaps allow the penis to ascend superiorly, the result is usually a large defect over the proximal shaft of the penis. The use of redundant dorsal penile skin fashioned into Byars flaps is sometimes insufficient to resurface the ventral aspect of the penile shaft. Furthermore, simple reapproximation of the penile skin to the scrotum may result in partial fusion between the scrotum and the penis (Fig. 2). We have used modified neurovascular pudendal-thigh flaps to correct the skin deficiency on the proximal penile shaft and prevent penoscrotal tethering postoperatively (Fig. 3). An axial skin flap is designed from the groin bilaterally, so that
INC.
PII
0090-4295/97/$17.00 s0090-4295(97)00341-5
597
09
FIGURE 2. Standard techniques result in partial fusion and tethering between the scrotum and the penis. (By permission of Mayo Foundation.)
(W FIGURE 1. (A) Hemicircumferential
incisions are made bilaterally around the superior aspect of the scrotum and penis. (B) incisions are carried on either side of the penis and connect in the midline just proximal to the urethral meatus. (By permission of Mayo Foundation.)
each flap will cover one-half of the defect (Fig. 4). A pattern of the defect is outlined and transferred to each groin. It is important that the flap be long enough to reach the tip of the penis without tension while the penis is held erect. The skin edges are incised, and the flaps are carefully elevated in a superior to inferior direction, with extreme caution taken to protect the axial blood supply. In the initial development of the flap, we maintain a plane of dissection above the fascia. More proximally, the dissection continues in a subfascial plane to enable the flap to be well mobilized and rotated 90” medially (Fig. 5). This ensures an adequate blood supply to the flap. The flaps are aligned in the midline and brought together with deep sutures of interrupted Vicryl. The inferior margins of the flaps are sutured to the upper margin of the scrotum. The donor sites are closed primarily and require only minimal mobilization of 598
FIGURE 3. Axial skin flaps are designed from the groins bilaterally. It is important that the flap be long enough to reach the tip of the penis without tension while the penis is held erect. (By permission of Mayo Foundation.)
the subcutaneous tissue. Jackson-Pratt drains are placed above the fascia of the thigh in both donor sites. Skin closure is accomplished with either subcuticular Vicryl or fine catgut (Fig. 6). The chordee is corrected by standard techniques. Urethroplasty is deferred for 6 to 12 months, at which time ample penile skin is available to proceed with a tension-free closure. UROLOGY
50 (41, 1997
FIGURE 4. The flaps are thicker proximally because the fascia is included to protect the neurovascular pedicle. (By permission of Mayo Foundation.]
Suprafascial , of elevation
plane
FIGURE 5. Transverse section of groin showing the proper plane of dissection. During the initial development of the flap, dissection proceeds in a suprafascial plane. More proximally, the dissection continues in a subfascial plane. (By permission of Mayo Foundation.)
COMMENT The goals of surgical correction of incomplete penoscrotal transposition include placement of the scrotum in its normal anatomic position, prevention of penoscrotal fusion and tethering, release of chordee, and urethroplasty to advance the urethral meatus to the glans tip. Standard surgical techniques include mobilization of the two halves of the scrotum as rotational advancement flaps, with relocation of the scrotum in a normal dependent position. Campbell3 described bisecting the scroUROLOGY
50 (41, 1997
FIGURE 6. The flaps are transposed medially and align in the midline to correct penoscrotal fusion and tethering. (By permission of Mayo Foundation.)
turn and suturing the two halves beneath the penis. McIlvoy and Harris4 placed the penis anterior to the scrotum through a subcutaneous tunnel. Glenn and Anderson’ described bilateral rotational advancement flaps with relocation of the scrotal compartment in a normal dependent position. Ehrlich and Scardino’ reported a modification of the Glenn-Anderson technique in which a midline skin bridge was left between the dorsal penile shaft and the suprapubic area. Rotational advancement flaps were then brought proximal to the urethral meatus. An occasional problem with these operations has been a deficiency of skin on the proximal penile shaft, resulting in penoscrotal fusion and tethering. The vascular basis of the pudendal-thigh flap has been well described and the flap subsequently used for vaginal reconstruction. Wee and Joseph5 defined the vascular supply to these flaps by using methylene blue injection, latex injection, and Batson’s corrosion cast techniques in female cadavers. The internal pudendal artery supplies the perineum by means of its first branch, the inferior rectal artery, and then the perineal artery (Fig. 7). The perineal artery enters the superficial perineal pouch at the base of the perineal membrane. This artery continues as the posterior labial artery (posterior scrotal artery in the male). The posterior labial arteries anastomose with branches of the deep external pudendal artery (main anastomoses), median femoral circumflex artery, and anterior branch of the obturator artery over the proximal portion of the adductor muscles. By a process of capturing adjacent territory, the posterior scrotal 599
ternal
1P
iliac
Posterior
a.
scrotal
a.
modified the original flap by dissecting the subcutaneous tissues in a suprafascial plane superiorly in the distal half of the flap. More proximally, the dissection is continued in a subfascial plane, enabling the flap to be well mobilized and rotated 90” medially. Dissecting in the subfascial plane in the inferior half ensures adequate blood supply to the flap by protecting the axial blood vessels supplying it. We have used this modified flap in 6 children over the past 24 months. Each patient has achieved an excellent cosmetic and functional result. There are several advantages of the modified pudendal-thigh flap for reconstruction of incomplete penoscrotal transposition. The technique is simple and can be completed in 1 hour or less with little or no blood loss. There is a reliable blood supply to the flaps that promotes early wound healing. The donor site scars are linear and well hidden in the groin crease and perineum. Interdigitation of sensate vascularized flaps between the base of the penis and the scrotum prevents postoperative tethering and penoscrotal fusion. This technique preserves sufficient penile skin for a tension-free second-stage urethroplasty. CONCLUSIONS
‘!
FIGURE 7. Vascular diagram shows anastomoses between the posterior scrotal arteries and the deeper external pudendal arteries. (By permission of Mayo Foundation.)
arteries extend to the femoral triangle and thus provide a reliable blood supply to the pudendalthigh flap. The neural innervation of the pudendal-thigh flap is well maintained. The posterior portion of the flap retains its innervation from posterior labial branches of the pudendal nerves and from the perineal rami of posterior cutaneous nerves of the thigh. The anterior portion of flap, near the femoral triangle, is supplied by nerve twigs of genitofemoral and ilioinguinal nerves. This area of the flap may be denervated in the process of mobilization. The use of the pudendal-thigh flap for correction of incomplete penoscrotal transposition has not been described previously. The vascular basis of this flap is the posterior scrotal artery. We have
600
In patients with incomplete penoscrotal transposition, the use of modified pudendal-thigh flaps allows well-vascularized tissue to resurface the proximal and inferior aspects of the penile shaft. The flaps provide a reliable blood supply, maintain normal innervation, and correct the problem of penoscrotal fusion and tethering postoperatively. These flaps can be used to close perineal wounds and fistulae and to reconstruct the scrotum or penis when local skin is deficient. REFERENCES 1. Glenn JF, and Anderson EE: Surgical correction of incomplete penoscrotal transposition. J Urol 110: 603-605, 1973. 2. Ehrlich RM, and Scardino PT: Surgical correction of scrotal transposition and perineal hypospadias. J Pediatr Surg 17: 175-177,
1982.
3. Campbell MF: Anomalies of the genital tract, in Campbell MF, and Harrison JH (Eds): Urology, 3rd ed. Philadelphia, WB Saunders, 1970, vol 2, pp 1576-1577. 4. McIlvoy DB, and Harris HS: Transposition of the penis and scrotum: case report. J Urol 73: 540-543, 1955. 5. Wee JT, and Joseph VT: A new technique of vaginal reconstruction using neurovascular pudendal-thigh flaps: a preliminary report. Plast Reconstr Surg 83: 701-709, 1989.
UROLOGY
SO (41, 1997
MODIFIED JAY
B.
PUDENDAL-THIGH PENOSCROTAL LEVY,
MICHAEL
F. DARSON,
Objectives. In patients with penoscrotal deficiency of skin on the proximal penile Methods. We describe a new operation of incomplete penoscrotal transposition. Results. This procedure has been used been achieved in each patient. Conclusions. The flaps provide a reliable of postoperative penoscrotal fusion and sion-free second-stage urethroplasty. rights reserved.
ULDIS
BITE,
AND
STEPHEN
OF
A. KRAMER
ABSTRACT transposition, an occasional postoperative problem has been a shaft that results in penoscrotal fusion and tethering. using a modified neurovascular pudendal-thigh flap for correction in 6 children,
and an excellent
cosmetic
and functional
result has
blood supply, maintain normal innervation, and correct the problem tethering. This technique preserves sufficient penile skin for a tenUROLOGY 50: 597-600, 1997. 0 1997, Elsevier Science Inc. All
P
enoscrotal transposition is an unusual anomaly of the external genitalia that is characterized by malposition of the penis in relation to the scrotum. Embryologically, penoscrotal transposition occurs when the labioscrotal swellings fail to migrate caudally at 9 to 10 weeks of gestation and fuse anteriorly or laterally to the genital tubercle. The transposition may be complete or incomplete. Patients with incomplete penoscrotal transposition usually have associated proximal hypospadias with severe chordee. Standard techniques include mobilization of the two halves of the scrotum as rotational advancement flaps with relocation of the scrotum in the normal dependent position.1%2 An occasional problem with these repairs is a deficiency of skin on the proximal penile shaft that produces tethering at the junction of the scrotum and base of the penis. We have used a modified neurovascular pudendal-thigh flap for correction of incomplete penoscrotal transposition. The bilateral flaps provide a reliable blood supply, maintain normal innervation, and correct the problem of penoscrotal fusion
From the Department of Urology and the Division of Plastic Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota Repr-int requests: Stephen A. Kramer, M.D., Department of Urology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 Submitted: March 27, 1997, accepted: June 3, 1997 0 1997, ELSEVIER SCIENCE ALL RIGHTS RESERVED
FLAP FOR CORRECTION TRANSPOSITION
and tethering postoperatively. serves sufficient penile skin ond-stage urethroplasty. SURGICAL
This technique for a tension-free
presec-
TECHNIQUE
The procedure is performed with the patient in the lithotomy position. Hemicircumferential incisions are made bilaterally above the scrotum to mobilize the scrotal halves as rotational advancement flaps (Fig. 1). A plane of dissection is developed subcutaneously, and the scrotal pedicles are transposed inferior to the penis. This recreates the normal anatomic configuration of the penis and scrotum. Most of these children have descended testes. However, mobilization of the spermatic cords is often necessary to bring the testes down into the relocated dependent scrotal position. Although these rotational flaps allow the penis to ascend superiorly, the result is usually a large defect over the proximal shaft of the penis. The use of redundant dorsal penile skin fashioned into Byars flaps is sometimes insufficient to resurface the ventral aspect of the penile shaft. Furthermore, simple reapproximation of the penile skin to the scrotum may result in partial fusion between the scrotum and the penis (Fig. 2). We have used modified neurovascular pudendal-thigh flaps to correct the skin deficiency on the proximal penile shaft and prevent penoscrotal tethering postoperatively (Fig. 3). An axial skin flap is designed from the groin bilaterally, so that
INC.
PII
0090-4295/97/$17.00 s0090-4295(97)00341-5
597
09
FIGURE 2. Standard techniques result in partial fusion and tethering between the scrotum and the penis. (By permission of Mayo Foundation.)
(W FIGURE 1. (A) Hemicircumferential
incisions are made bilaterally around the superior aspect of the scrotum and penis. (B) incisions are carried on either side of the penis and connect in the midline just proximal to the urethral meatus. (By permission of Mayo Foundation.)
each flap will cover one-half of the defect (Fig. 4). A pattern of the defect is outlined and transferred to each groin. It is important that the flap be long enough to reach the tip of the penis without tension while the penis is held erect. The skin edges are incised, and the flaps are carefully elevated in a superior to inferior direction, with extreme caution taken to protect the axial blood supply. In the initial development of the flap, we maintain a plane of dissection above the fascia. More proximally, the dissection continues in a subfascial plane to enable the flap to be well mobilized and rotated 90” medially (Fig. 5). This ensures an adequate blood supply to the flap. The flaps are aligned in the midline and brought together with deep sutures of interrupted Vicryl. The inferior margins of the flaps are sutured to the upper margin of the scrotum. The donor sites are closed primarily and require only minimal mobilization of 598
FIGURE 3. Axial skin flaps are designed from the groins bilaterally. It is important that the flap be long enough to reach the tip of the penis without tension while the penis is held erect. (By permission of Mayo Foundation.)
the subcutaneous tissue. Jackson-Pratt drains are placed above the fascia of the thigh in both donor sites. Skin closure is accomplished with either subcuticular Vicryl or fine catgut (Fig. 6). The chordee is corrected by standard techniques. Urethroplasty is deferred for 6 to 12 months, at which time ample penile skin is available to proceed with a tension-free closure. UROLOGY
50 (41, 1997
FIGURE 4. The flaps are thicker proximally because the fascia is included to protect the neurovascular pedicle. (By permission of Mayo Foundation.]
Suprafascial , of elevation
plane
FIGURE 5. Transverse section of groin showing the proper plane of dissection. During the initial development of the flap, dissection proceeds in a suprafascial plane. More proximally, the dissection continues in a subfascial plane. (By permission of Mayo Foundation.)
COMMENT The goals of surgical correction of incomplete penoscrotal transposition include placement of the scrotum in its normal anatomic position, prevention of penoscrotal fusion and tethering, release of chordee, and urethroplasty to advance the urethral meatus to the glans tip. Standard surgical techniques include mobilization of the two halves of the scrotum as rotational advancement flaps, with relocation of the scrotum in a normal dependent position. Campbell3 described bisecting the scroUROLOGY
50 (41, 1997
FIGURE 6. The flaps are transposed medially and align in the midline to correct penoscrotal fusion and tethering. (By permission of Mayo Foundation.)
turn and suturing the two halves beneath the penis. McIlvoy and Harris4 placed the penis anterior to the scrotum through a subcutaneous tunnel. Glenn and Anderson’ described bilateral rotational advancement flaps with relocation of the scrotal compartment in a normal dependent position. Ehrlich and Scardino’ reported a modification of the Glenn-Anderson technique in which a midline skin bridge was left between the dorsal penile shaft and the suprapubic area. Rotational advancement flaps were then brought proximal to the urethral meatus. An occasional problem with these operations has been a deficiency of skin on the proximal penile shaft, resulting in penoscrotal fusion and tethering. The vascular basis of the pudendal-thigh flap has been well described and the flap subsequently used for vaginal reconstruction. Wee and Joseph5 defined the vascular supply to these flaps by using methylene blue injection, latex injection, and Batson’s corrosion cast techniques in female cadavers. The internal pudendal artery supplies the perineum by means of its first branch, the inferior rectal artery, and then the perineal artery (Fig. 7). The perineal artery enters the superficial perineal pouch at the base of the perineal membrane. This artery continues as the posterior labial artery (posterior scrotal artery in the male). The posterior labial arteries anastomose with branches of the deep external pudendal artery (main anastomoses), median femoral circumflex artery, and anterior branch of the obturator artery over the proximal portion of the adductor muscles. By a process of capturing adjacent territory, the posterior scrotal 599
ternal
1P
iliac
Posterior
a.
scrotal
a.
modified the original flap by dissecting the subcutaneous tissues in a suprafascial plane superiorly in the distal half of the flap. More proximally, the dissection is continued in a subfascial plane, enabling the flap to be well mobilized and rotated 90” medially. Dissecting in the subfascial plane in the inferior half ensures adequate blood supply to the flap by protecting the axial blood vessels supplying it. We have used this modified flap in 6 children over the past 24 months. Each patient has achieved an excellent cosmetic and functional result. There are several advantages of the modified pudendal-thigh flap for reconstruction of incomplete penoscrotal transposition. The technique is simple and can be completed in 1 hour or less with little or no blood loss. There is a reliable blood supply to the flaps that promotes early wound healing. The donor site scars are linear and well hidden in the groin crease and perineum. Interdigitation of sensate vascularized flaps between the base of the penis and the scrotum prevents postoperative tethering and penoscrotal fusion. This technique preserves sufficient penile skin for a tension-free second-stage urethroplasty. CONCLUSIONS
‘!
FIGURE 7. Vascular diagram shows anastomoses between the posterior scrotal arteries and the deeper external pudendal arteries. (By permission of Mayo Foundation.)
arteries extend to the femoral triangle and thus provide a reliable blood supply to the pudendalthigh flap. The neural innervation of the pudendal-thigh flap is well maintained. The posterior portion of the flap retains its innervation from posterior labial branches of the pudendal nerves and from the perineal rami of posterior cutaneous nerves of the thigh. The anterior portion of flap, near the femoral triangle, is supplied by nerve twigs of genitofemoral and ilioinguinal nerves. This area of the flap may be denervated in the process of mobilization. The use of the pudendal-thigh flap for correction of incomplete penoscrotal transposition has not been described previously. The vascular basis of this flap is the posterior scrotal artery. We have
600
In patients with incomplete penoscrotal transposition, the use of modified pudendal-thigh flaps allows well-vascularized tissue to resurface the proximal and inferior aspects of the penile shaft. The flaps provide a reliable blood supply, maintain normal innervation, and correct the problem of penoscrotal fusion and tethering postoperatively. These flaps can be used to close perineal wounds and fistulae and to reconstruct the scrotum or penis when local skin is deficient. REFERENCES 1. Glenn JF, and Anderson EE: Surgical correction of incomplete penoscrotal transposition. J Urol 110: 603-605, 1973. 2. Ehrlich RM, and Scardino PT: Surgical correction of scrotal transposition and perineal hypospadias. J Pediatr Surg 17: 175-177,
1982.
3. Campbell MF: Anomalies of the genital tract, in Campbell MF, and Harrison JH (Eds): Urology, 3rd ed. Philadelphia, WB Saunders, 1970, vol 2, pp 1576-1577. 4. McIlvoy DB, and Harris HS: Transposition of the penis and scrotum: case report. J Urol 73: 540-543, 1955. 5. Wee JT, and Joseph VT: A new technique of vaginal reconstruction using neurovascular pudendal-thigh flaps: a preliminary report. Plast Reconstr Surg 83: 701-709, 1989.
UROLOGY
SO (41, 1997