Discussion
This case series presents an alternative method for reconstruction of
circumferential pharyngeal defects using a dual flap technique, with the
rotated deltopectoral flap as the posterior wall of the neopharynx. The
purpose of this technique is to reconstruct the neopharynx with minimal
soft tissue bulk in the limited central compartment space, and to create
a wider, conical conduit for food passage. A single tubed flap, with the
exception of the jejunal free flap, incorporates all the flap bulk in
the central compartment, limiting the calibre of the neopharynx. The
deltopectoral flap positions naturally on the prevertebral fascia. The
second flap being used as a patch flap as opposed to a tubed flap,
allows the majority of the flap bulk to be located in the lateral neck.
To maintain continuity of the neopharynx, the flaps need to be sutured
stepwise to the posterior pharyngeal wall postero-superiorly and to the
tongue base supero-anteriorly. Similarly, the flaps are sutured
inferiorly to the cervical oesophageal remnant forming a continuous food
passage. This resulted in a conical shaped neopharynx (Figure 2), which
resembles the natural pharynx more than a tubed flap reconstruction. The
authors theorise that this wider, conical neopharynx would both enhance
the swallow function, and allow improved air passage for speech. Our
limited series seems to support this, with good functional outcomes
reported.
The additional advantage to the DP flap, is that it can be rapidly
raised and positioned on the posterior wall, requiring minimal
de-epithelialisation. This also converts a complex circumferential
defect into a ‘partial’ defect, and consequently, does not contribute
significantly to the surgical time.
To the authors knowledge, the combination of a DP and a second flap has
never been described before in the literature. Various techniques have
been described for reconstructing circumferential defects, including
tubed free flaps, tubed pedicled flaps, and suturing of flaps onto the
prevertebral fascia. A recent multicentre study concluded that the type
of flap used during reconstruction does not impact on the post-operative
swallowing outcomes with just over half of patients being able to gain
normal diet post-operatively (54% with any flaps; 63% RFFF. 53% PMMC,
58% FJF) with no significant difference between the different flaps
being used. 5 Nevertheless, other series have
demonstrated superior functional outcomes when free flaps were used
(58% - 63% normal feeding; 21-25% stricture requiring dilatation)
compared to tubed PMMC or PMMC with the prevertebral fascia forming the
posterior pharyngeal wall (18-40% stenosis requiring dilatation;
53-91% adequate oral nutrition; 43% satisfactory vocal function).10-13
In our case series, all patients ultimately achieved oral diet intake,
with 7 patients achieving sufficient intake to support their complete
nutrition. Only one patient developed a stricture requiring repeated
dilatation. All patients who were able to receive a tracheooesophageal
puncture attained intelligible speech. The need for post-operative
dilatation of the neopharynx is frequently reported in the literature
when tubed free or single pedicle flaps are used for reconstruction of
circumferential pharyngolaryngeal defects. Dilatation figures vary from
21% with the FFF to 40% with PMMC. 5
The main weakness of the dual flap technique lies in the likelihood of
patients developing a small fistula. This occurs at the
de-epithelialised region on the DP flap. While an important
consideration in the perioperative period, this has not impacted on
subsequent care or adjuvant treatment delivery in any of the patients
involved. The fistula has always remained small and low volume,
requiring minimal/no intervention, and the authors are of the opinion
that the long-term functional outcome advantages outweigh the
consequences of fistula development. In fact, it may be that the small
fistula is advantageous, allowing a means of controlled drainage, as
none of the patients have developed significant tissue breakdown. The
factors that pre-dispose to fistulae have been investigated extensively
in previous studies, including comparing between free and pedicled
tissue flaps. 14-16 Despite a recent trend towards
increasing free flap use, morbidity profiles appear to be similar
between free and pedicled flaps 16. Although all
patients in our case series developed a fistula, the short-lived nature,
and the rapid healing indicate that dual flap use appears to be a robust
reconstruction technique.